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  • richardmitnick 9:48 pm on November 30, 2022 Permalink | Reply
    Tags: "Einstein–Rosen bridges", "EPR": Einstein-Podolsky-Rosen, "ER = EPR" theory, "Physicists observe wormhole dynamics using a quantum computer", "SYK" model: Subir Sachdev- Jinwu Ye- Alexei Kitaev, , , , Juan Maldacena and Leonard Susskind in 2013 first proposed the notion that wormholes and quantum physics may have a connection., , Quantum entanglement, , Some theoretical wormhole ideas could be studied more deeply by doing experiments on quantum processors., , The physicists [Juan Maldacena and Leonard Susskind] speculated that wormholes (or "ER") were equivalent to entanglement., The research is a step toward studying "quantum gravity" in the lab., The term "wormhole" itself was coined by physicist John Wheeler in the 1950s.   

    From The California Institute of Technology: “Physicists observe wormhole dynamics using a quantum computer” 

    Caltech Logo

    From The California Institute of Technology

    11.30.22
    Whitney Clavin
    (626) 395‑1944
    wclavin@caltech.edu

    1
    Artwork depicting a quantum experiment that studies traversable wormholes. Credit: inqnet/A. Mueller (Caltech)

    The research is a step toward studying “quantum gravity” in the lab.

    Scientists have, for the first time, developed a quantum experiment that allows them to study the dynamics, or behavior, of a special kind of theoretical wormhole. The experiment has not created an actual wormhole (a rupture in space and time), rather it allows researchers to probe connections between theoretical wormholes and quantum physics, a prediction of so-called quantum gravity. Quantum gravity refers to a set of theories that seek to connect gravity with quantum physics, two fundamental and well-studied descriptions of nature that appear inherently incompatible with each other.

    “We found a quantum system that exhibits key properties of a gravitational wormhole yet is sufficiently small to implement on today’s quantum hardware,” says Maria Spiropulu, the principal investigator of the U.S. Department of Energy Office of Science research program Quantum Communication Channels for Fundamental Physics (QCCFP) and the Shang-Yi Ch’en Professor of Physics at Caltech. “This work constitutes a step toward a larger program of testing quantum gravity physics using a quantum computer. It does not substitute for direct probes of quantum gravity in the same way as other planned experiments that might probe quantum gravity effects in the future using quantum sensing, but it does offer a powerful testbed to exercise ideas of quantum gravity.”

    The research will be published December 1 in the journal Nature [below]. The study’s first authors are Daniel Jafferis of Harvard University and Alexander Zlokapa (BS ’21), a former undergraduate student at Caltech who started on this project for his bachelor’s thesis with Spiropulu and has since moved on to graduate school at MIT.

    Wormholes are bridges between two remote regions in spacetime. They have not been observed experimentally, but scientists have theorized about their existence and properties for close to 100 years. In 1935, Albert Einstein and Nathan Rosen described wormholes as tunnels through the fabric of spacetime in accordance with Einstein’s General Theory of Relativity, which describes gravity as a curvature of spacetime. Researchers call wormholes “Einstein–Rosen bridges” after the two physicists who invoked them, while the term “wormhole” itself was coined by physicist John Wheeler in the 1950s.

    The notion that wormholes and quantum physics, specifically entanglement (a phenomenon in which two particles can remain connected across vast distances), may have a connection was first proposed in theoretical research by Juan Maldacena and Leonard Susskind in 2013. The physicists speculated that wormholes (or “ER”) were equivalent to entanglement (also known as “EPR” after Albert Einstein, Boris Podolsky [PhD ’28], and Nathan Rosen, who first proposed the concept). In essence, this work established a new kind of theoretical link between the worlds of gravity and quantum physics. “It was a very daring and poetic idea,” says Spiropulu of the “ER = EPR” work.

    Later, in 2017, Jafferis, along with his colleagues Ping Gao and Aron Wall, extended the “ER = EPR” idea to not just wormholes but traversable wormholes. The scientists concocted a scenario in which negative repulsive energy holds a wormhole open long enough for something to pass through from one end to the other. The researchers showed that this gravitational description of a traversable wormhole is equivalent to a process known as quantum teleportation. In quantum teleportation, a protocol that has been experimentally demonstrated over long distances via optical fiber and over the air, information is transported across space using the principles of quantum entanglement.

    The present work explores the equivalence of wormholes with quantum teleportation. The Caltech-led team performed the first experiments that probe the idea that information traveling from one point in space to another can be described in either the language of gravity (the wormholes) or the language of quantum physics (quantum entanglement).

    A key finding that inspired possible experiments occurred in 2015, when Caltech’s Alexei Kitaev, the Ronald and Maxine Linde Professor of Theoretical Physics and Mathematics, showed that a simple quantum system could exhibit the same duality later described by Gao, Jafferis, and Wall, such that the model’s quantum dynamics are equivalent to quantum gravity effects. This Sachdev–Ye–Kitaev, or SYK model (named after Kitaev, and Subir Sachdev and Jinwu Ye, two other researchers who worked on its development previously) led researchers to suggest that some theoretical wormhole ideas could be studied more deeply by doing experiments on quantum processors.

    Furthering these ideas, in 2019, Jafferis and Gao showed that by entangling two “SYK” models, researchers should be able to perform wormhole teleportation and thus produce and measure the dynamical properties expected of traversable wormholes.

    In the new study, the team of physicists performed this type of experiment for the first time. They used a “baby” “SYK”-like model prepared to preserve gravitational properties, and they observed the wormhole dynamics on a quantum device at Google, namely the Sycamore quantum processor.

    To accomplish this, the team had to first reduce the “SYK” model to a simplified form, a feat they achieved using machine learning tools on conventional computers.

    “We employed learning techniques to find and prepare a simple “SYK”-like quantum system that could be encoded in the current quantum architectures and that would preserve the gravitational properties,” says Spiropulu. “In other words, we simplified the microscopic description of the “SYK’ quantum system and studied the resulting effective model that we found on the quantum processor. It is curious and surprising how the optimization on one characteristic of the model preserved the other metrics! We have plans for more tests to get better insights on the model itself.”

    In the experiment, the researchers inserted a qubit—the quantum equivalent of a bit in conventional silicon-based computers—into one of their “SYK”-like systems and observed the information emerge from the other system. The information traveled from one quantum system to the other via quantum teleportation—or, speaking in the complementary language of gravity, the quantum information passed through the traversable wormhole.

    “We performed a kind of quantum teleportation equivalent to a traversable wormhole in the gravity picture. To do this, we had to simplify the quantum system to the smallest example that preserves gravitational characteristics so we could implement it on the Sycamore quantum processor at Google,” says Zlokapa.

    Co-author Samantha Davis, a graduate student at Caltech, adds, “It took a really long time to arrive at the results, and we surprised ourselves with the outcome.”

    “The near-term significance of this type of experiment is that the gravitational perspective provides a simple way to understand an otherwise mysterious many-particle quantum phenomenon,” says John Preskill, the Richard P. Feynman Professor of Theoretical Physics at Caltech and director of the Institute for Quantum Information and Matter (IQIM). “What I found interesting about this new Google experiment is that, via machine learning, they were able to make the system simple enough to simulate on an existing quantum machine while retaining a reasonable caricature of what the gravitation picture predicts.”

    In the study, the physicists report wormhole behavior expected both from the perspectives of gravity and from quantum physics. For example, while quantum information can be transmitted across the device, or teleported, in a variety of ways, the experimental process was shown to be equivalent, at least in some ways, to what might happen if information traveled through a wormhole. To do this, the team attempted to “prop open the wormhole” using pulses of either negative repulsive energy pulse or the opposite, positive energy. They observed key signatures of a traversable wormhole only when the equivalent of negative energy was applied, which is consistent with how wormholes are expected to behave.

    “The high fidelity of the quantum processor we used was essential,” says Spiropulu. “If the error rates were higher by 50 percent, the signal would have been entirely obscured. If they were half we would have 10 times the signal!”

    In the future, the researchers hope to extend this work to more complex quantum circuits. Though bona fide quantum computers may still be years away, the team plans to continue to perform experiments of this nature on existing quantum computing platforms.

    “The relationship between quantum entanglement, spacetime, and quantum gravity is one of the most important questions in fundamental physics and an active area of theoretical research,” says Spiropulu. “We are excited to take this small step toward testing these ideas on quantum hardware and will keep going.”

    More information can be found at the Alliance for Quantum Technologies website: https://inqnet.caltech.edu/wormhole2022.

    Science paper:
    Nature

    See the full article here .

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”


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    Please help promote STEM in your local schools.

    Stem Education Coalition

    Caltech campus

    The California Institute of Technology is a private research university in Pasadena, California. The university is known for its strength in science and engineering, and is one among a small group of institutes of technology in the United States which is primarily devoted to the instruction of pure and applied sciences.

    The California Institute of Technology was founded as a preparatory and vocational school by Amos G. Throop in 1891 and began attracting influential scientists such as George Ellery Hale, Arthur Amos Noyes, and Robert Andrews Millikan in the early 20th century. The vocational and preparatory schools were disbanded and spun off in 1910 and the college assumed its present name in 1920. In 1934, The California Institute of Technology was elected to the Association of American Universities, and the antecedents of National Aeronautics and Space Administration ‘s Jet Propulsion Laboratory, which The California Institute of Technology continues to manage and operate, were established between 1936 and 1943 under Theodore von Kármán.

    The California Institute of Technology has six academic divisions with strong emphasis on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. First-year students are required to live on campus, and 95% of undergraduates remain in the on-campus House System at The California Institute of Technology. Although The California Institute of Technology has a strong tradition of practical jokes and pranks, student life is governed by an honor code which allows faculty to assign take-home examinations. The The California Institute of Technology Beavers compete in 13 intercollegiate sports in the NCAA Division III’s Southern California Intercollegiate Athletic Conference (SCIAC).

    As of October 2020, there are 76 Nobel laureates who have been affiliated with The California Institute of Technology, including 40 alumni and faculty members (41 prizes, with chemist Linus Pauling being the only individual in history to win two unshared prizes). In addition, 4 Fields Medalists and 6 Turing Award winners have been affiliated with The California Institute of Technology. There are 8 Crafoord Laureates and 56 non-emeritus faculty members (as well as many emeritus faculty members) who have been elected to one of the United States National Academies. Four Chief Scientists of the U.S. Air Force and 71 have won the United States National Medal of Science or Technology. Numerous faculty members are associated with the Howard Hughes Medical Institute as well as National Aeronautics and Space Administration. According to a 2015 Pomona College study, The California Institute of Technology ranked number one in the U.S. for the percentage of its graduates who go on to earn a PhD.

    Research

    The California Institute of Technology is classified among “R1: Doctoral Universities – Very High Research Activity”. Caltech was elected to The Association of American Universities in 1934 and remains a research university with “very high” research activity, primarily in STEM fields. The largest federal agencies contributing to research are National Aeronautics and Space Administration; National Science Foundation; Department of Health and Human Services; Department of Defense, and Department of Energy.

    In 2005, The California Institute of Technology had 739,000 square feet (68,700 m^2) dedicated to research: 330,000 square feet (30,700 m^2) to physical sciences, 163,000 square feet (15,100 m^2) to engineering, and 160,000 square feet (14,900 m^2) to biological sciences.

    In addition to managing NASA-JPL/Caltech , The California Institute of Technology also operates the Caltech Palomar Observatory; the Owens Valley Radio Observatory;the Caltech Submillimeter Observatory; the W. M. Keck Observatory at the Mauna Kea Observatory; the Laser Interferometer Gravitational-Wave Observatory at Livingston, Louisiana and Hanford, Washington; and Kerckhoff Marine Laboratory in Corona del Mar, California. The Institute launched the Kavli Nanoscience Institute at The California Institute of Technology in 2006; the Keck Institute for Space Studies in 2008; and is also the current home for the Einstein Papers Project. The Spitzer Science Center, part of the Infrared Processing and Analysis Center located on The California Institute of Technology campus, is the data analysis and community support center for NASA’s Spitzer Infrared Space Telescope [no longer in service].

    The California Institute of Technology partnered with University of California at Los Angeles to establish a Joint Center for Translational Medicine (UCLA-Caltech JCTM), which conducts experimental research into clinical applications, including the diagnosis and treatment of diseases such as cancer.

    The California Institute of Technology operates several Total Carbon Column Observing Network stations as part of an international collaborative effort of measuring greenhouse gases globally. One station is on campus.

     
  • richardmitnick 1:57 pm on November 13, 2022 Permalink | Reply
    Tags: , , , , , Quantum entanglement, "New Entanglement Results Hint at Better Quantum Codes", Two entangled quantum particles must be considered a single system., The phenomenon of “nonlocality” means that the system you have in front of you can be instantaneously affected by something that’s thousands of miles away., Encryption   

    From “Quanta Magazine” : “New Entanglement Results Hint at Better Quantum Codes” 

    From “Quanta Magazine”

    10.24.22 [Just found this.]
    Allison Parshall

    1
    Three-way entanglement represents one small step toward a global quantum internet. Credit: Kristina Armitage/Quanta Magazine.

    This month, three scientists won the Nobel Prize in Physics for their work proving one of the most counterintuitive yet consequential realities of the quantum world. They showed that two entangled quantum particles must be considered a single system — their states inexorably intertwined with each other — even if the particles are separated by great distances. In practice, this phenomenon of “nonlocality” means that the system you have in front of you can be instantaneously affected by something that’s thousands of miles away.

    Entanglement and nonlocality enable computer scientists to create uncrackable codes. In a technique known as device-independent quantum key distribution, a pair of particles is entangled and then distributed to two people. The particles’ shared properties can now serve as a code, one that will keep communications safe even from quantum computers — machines capable of breaking through classical encryption techniques.

    But why stop at two particles? In theory, there’s no upper limit on how many particles can share an entangled state. For decades, theoretical physicists have imagined three-way, four-way, even 100-way quantum connections — the sort of thing that would allow a fully distributed quantum-protected internet. Now, a lab in China has achieved what appears to be nonlocal entanglement between three particles at once, potentially boosting the strength of quantum cryptography and the possibilities for quantum networks generally.

    “Two-party nonlocality is crazy enough as it is,” said Peter Bierhorst, a quantum information theorist at the University of New Orleans. “But it turns out quantum mechanics can do stuff that even goes beyond that when you have three parties.”

    Physicists have entangled more than two particles before. The record is somewhere between 14 particles and 15 trillion, depending on whom you ask. But these were only across short distances, just inches apart at the most. To make multiparty entanglement useful for cryptography, scientists need to go beyond simple entanglement and demonstrate nonlocality — “a high bar to achieve,” said Elie Wolfe, a quantum theorist at the Perimeter Institute for Theoretical Physics in Waterloo, Canada.

    The key to proving nonlocality is to test whether the properties of one particle match up with the properties of the other — the hallmark of entanglement — once they’re far enough apart that nothing else could cause the effects. For example, a particle that’s still physically close to its entangled twin might emit radiation that affects the other. But if they’re a mile apart and measured practically instantaneously, then they are likely linked only by entanglement. The experimenters use a set of equations called Bell inequalities to rule out all other explanations for the particles’ linked properties.

    With three particles, the process of proving nonlocality is similar, but there are more possibilities to rule out. This balloons the complexity of both the measurements and the mathematical hoops that the scientists must jump through to prove the nonlocal relationship of the three particles. “You have to come up with a creative way to approach it,” Bierhorst said — and have the technology to create just the right conditions in the lab.

    In results published in August [Physical Review Letters (below)], a team in Hefei, China, made a crucial leap forward. First, by shooting lasers through a special type of crystal, they entangled three photons and placed them in different areas of the research facility, hundreds of meters apart. Then they simultaneously measured a random property of each photon. The researchers analyzed the measurements and found that the relationship between the three particles was best explained by three-way quantum nonlocality. It was the most comprehensive demonstration of three-way nonlocality to date.

    Technically, there remains a small chance that something else caused the results. “We still have some open loopholes,” said Xuemei Gu, one of the lead authors of the study. But by separating the particles, they were able to rule out the most glaring alternative explanation for their data: physical proximity.

    The authors also based their experiment on a new, stricter definition [Physical Review Letters (below)] of three-way nonlocality that has been gaining traction in the past few years. Whereas past experiments allowed for cooperation between the devices that measured the photons, Gu’s three devices could not communicate. Instead, they made random measurements of the particles — a restriction that would be useful in cryptographic scenarios where any communication can be compromised, said Renato Renner, a quantum physicist at the Swiss Federal Institute of Technology Zurich. (Using the older paradigm, a Canadian team demonstrated three-way nonlocality at a distance in 2014 [Nature Photonics] (below).)

    Now that researchers following the new definition have successfully entangled particles this far apart, they can focus on expanding the distance even further.

    “It’s an important steppingstone toward doing longer-distance, bigger-scale experiments,” said Saikat Guha, a quantum information theorist at the University of Arizona.

    Most directly, this technology can power more expansive quantum key distribution, Renner said. If you use entangled particles as the key to encryption, the same Bell inequalities that physicists use to test for nonlocality can ensure that your secret is completely secure. Then even if the device you use to send or receive a message gets maliciously manipulated by your worst enemy, they won’t be able to determine your quantum key. Those secrets stay between you and whoever has the other entangled particle.

    2
    Researchers in China entangled three particles and placed them hundreds of meters apart in facilities labeled Alice, Bob and Charlie.

    Quantum key distribution is “the thing people are excited about,” Renner said. Last year, three separate groups demonstrated the protocol in the lab, though still on a small scale. That’s why three-way nonlocality will be so important. “You have in principle much more cryptographic power,” because these three-way connections cannot be simulated by cobbling together a few two-way links.

    “It’s a fundamentally new level of phenomena,” Bierhorst said, one that could expand device-independent cryptography from basic, two-way communication to an entire network of secret-sharers.

    Besides cryptography, multiparty entanglement also opens up possibilities for other types of quantum networks. Researchers like Guha are working on a quantum internet, which could link up quantum computers the way the regular internet connects ordinary devices. This system would bring together the computing power of many quantum devices by connecting millions of particles with varying levels of entanglement across varying distances. We have all the individual building blocks for such a system, Guha said, but assembling it “is a huge, huge engineering challenge.” With this goal in mind, scientists in the Netherlands have succeeded [Nature (below)] in entangling three particles in a network spanning two separate labs — though unlike Gu’s team, they weren’t focused on demonstrating nonlocality.

    This work on three-way entanglement started as “just an interesting phenomenon,” said Bierhorst. But “when you have something that quantum mechanics can do that it’s impossible to do otherwise, that’s going to open up all sorts of new technological possibilities that can be exploited in unforeseen ways.”

    For now, a few labs have demonstrated four-way nonlocality between particles that are very close together. “These experiments are pretty speculative at this point. You have to make a lot of assumptions,” said Bierhorst.

    The three-way experiments still rely on some assumptions as well. The Nobel laureates spent half a century ruling out those loopholes in their two-way experiments, finally succeeding in 2017. But we’ve come a long way since then technologically, said Renner.

    “What [took] decades before will now happen in a year or so,” he said.

    Science papers:
    Physical Review Letters
    Physical Review Letters 2021
    Nature Photonics 2014
    Nature
    See this science paper for instructive material with images.

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition

    Formerly known as Simons Science News, Quanta Magazine is an editorially independent online publication launched by the Simons Foundation to enhance public understanding of science. Why Quanta? Albert Einstein called photons “quanta of light.” Our goal is to “illuminate science.” At Quanta Magazine, scientific accuracy is every bit as important as telling a good story. All of our articles are meticulously researched, reported, edited, copy-edited and fact-checked.

     
  • richardmitnick 8:37 pm on October 20, 2022 Permalink | Reply
    Tags: "An Entangled Matter-wave Interferometer - Now with Double the Spookiness!", "De’Broglie waves": waves made of matter., "Delocalization": the fact that a single atom can be in more than one place at the same time., "Matter-wave interferometer", "Quantum nondemolition measurement", A better quantum sensor: entanglement between atoms and delocalization of atoms., , , JILA - [The Joint Institute for Laboratory Astrophysics] Exploring the Frontiers of Physics (University of Colorado-Boulder and NIST), , , , Quantum entanglement, , The Thompson group has learned how to entangle thousands to millions of atoms even when they are millimeters or more apart., Using an optical cavity to allow information to jump between the atoms and knit them into an entangled state.   

    From JILA – [The Joint Institute for Laboratory Astrophysics] Exploring the Frontiers of Physics (University of Colorado-Boulder and NIST): “An Entangled Matter-wave Interferometer – Now with Double the Spookiness!” 

    From JILA – [The Joint Institute for Laboratory Astrophysics] Exploring the Frontiers of Physics (University of Colorado-Boulder and NIST)

    10.20.22
    Kenna Hughes-Castleberry

    1
    A rendering of the entangled atoms within the interferometer. Image Credit: Steven Burrows/Thompson Group.

    JILA and NIST Fellow James K. Thompson’s team of researchers have for the first time successfully combined two of the “spookiest” features of quantum mechanics to make a better quantum sensor: entanglement between atoms and “delocalization” of atoms. Einstein originally referred to entanglement as creating spooky action at a distance—the strange effect of quantum mechanics in which what happens to one atom somehow influences another atom somewhere else. Entanglement is at the heart of hoped-for quantum computers, quantum simulators and quantum sensors. A second rather spooky aspect of quantum mechanics is “delocalization”: the fact that a single atom can be in more than one place at the same time. As described in their paper recently published in Nature [below], the Thompson group has combined the spookiness of both entanglement and delocalization to realize a “matter-wave interferometer” that can sense accelerations with a precision that surpasses the standard quantum limit (a limit on the accuracy of an experimental measurement at a quantum level) for the first time. By doubling down on the spookiness, future quantum sensors will be able to provide more precise navigation, explore for needed natural resources, more precisely determine fundamental constants such as the fine structure and gravitational constants, look more precisely for dark matter, or maybe even one day detect gravitational waves.

    Generating Entanglement

    To entangle two objects, one must typically bring them very, very close to each other so they can interact. The Thompson group has learned how to entangle thousands to millions of atoms even when they are millimeters or more apart. They do this by using light bouncing between mirrors, called an optical cavity to allow information to jump between the atoms and knit them into an entangled state. Using this unique light-based approach, they have created and observed some of the most highly entangled states ever generated in any system be it atomic, photonic, or solid state. Using this technique, the group designed two distinct experimental approaches, both of which they utilized in their recent work. In the first approach, called a “quantum nondemolition measurement”, they make a premeasurement of the quantum noise associated with their atoms and simply subtract the quantum noise from their final measurement. In a second approach, light injected into the cavity causes the atoms to undergo one-axis twisting, a process in which the quantum noise of each atom becomes correlated with the quantum noise of all the other atoms so that they can conspire together to become quieter. “The atoms are kind of like kids shushing each other to be quiet so they can hear about the party the teacher has promised them, but here it’s the entanglement that does the shushing,” says Thompson.

    “Matter-wave Interferometer”

    One of the most precise and accurate quantum sensors today is the “matter-wave interferometer”. The idea is that one uses pulses of light to cause atoms to simultaneously move and not move by having both absorbed and not absorbed laser light. This causes the atoms over time to simultaneously be in two different places at once. As graduate student Chengyi Luo explained, “We shine laser beams on the atoms so we actually split each atom’s quantum wave packet in two, in other words, the particle actually exists in two separate spaces at the same time.” Later pulses of laser light then reverse the process bringing the quantum wave packets back together so that any changes in the environment such as accelerations or rotations can be sensed by a measurable amount of interference happening to the two parts of the atomic wave packet, much like is done with light fields in normal interferometers, but here with “de’Broglie waves”, or waves made of matter. The team of JILA graduate students figured out how to make all of this work inside of an optical cavity with highly-reflective mirrors. They could measure how far the atoms fell along the vertically-oriented cavity due to gravity in a quantum version of Galileo’s gravity experiment dropping items from the Leaning Tower of Pisa, but with all the benefits of precision and accuracy that comes along from quantum mechanics.

    Doubling the Spookiness

    By learning how to operate a matter-wave interferometer inside of an optical cavity, the team of graduate students lead by Chengyi Luo and Graham Greve were then able to take advantage of the light-matter interactions to create entanglement between the different atoms to make a quieter and more precise measurement of the acceleration due to gravity. This is the first time that anyone has been able to observe a matter-wave interferometer with a precision that surpasses the standard quantum limit on precision set by the quantum noise of unentangled atoms.

    Thanks to the enhanced precision, researchers like Luo and Thompson see many future benefits for utilizing entanglement as a resource in quantum sensors. Thompson says, “I think that one day we will be able to introduce entanglement into matter-wave interferometers for detecting gravitational waves in space, or for dark matter searches—things that probe fundamental physics, as well as devices that can be used for every day applications such as navigation or geodesy.” With this momentous experimental advance, Thompson and his team hope that others will use this new entangled interferometer approach to lead to other advances in the field of physics. With optimism, Thompson says, “By learning to harness and control all of the spookiness we already know about, maybe we can discover new spooky things about the universe that we haven’t even thought of yet!”

    Science paper:
    Nature
    See the science paper for detailed material with images.

    See the full article here.

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    JILA, formerly known as the Joint Institute for Laboratory Astrophysics, is a physical science research institute in the United States. JILA is located on The University of Colorado-Boulder campus. JILA was founded in 1962 as a joint institute of The University of Colorado Boulder and the National Institute of Standards & Technology.

    JILA is one of the nation’s leading research institutes in the physical sciences. The world’s first Bose-Einstein Condensate was created at JILA by Eric Cornell and Carl Wieman in 1995. The first frequency comb demonstration was led by John L. Hall at JILA. The first demonstrations of a Fermionic condensate and BEC-BCS crossover physics were done by Deborah S. Jin.

    JILA’s members hold faculty appointments in the Departments of Physics; Astrophysical and Planetary Science; Chemistry and Biochemistry; and Molecular, Cellular, and Developmental Biology as well as Engineering. JILA’s Quantum Physics Division of NIST members hold joint faculty appointments at CU in the same departments.

    Research at JILA addresses fundamental scientific questions about the limits of quantum measurements and technologies, the design of precision optical and X-ray lasers, the fundamental principles underlying the interaction of light and matter, the role of quantum physics in chemistry and biology, and the processes that have governed the evolution of the Universe for nearly 14 billion years.

     
  • richardmitnick 2:14 pm on October 10, 2022 Permalink | Reply
    Tags: "Black Holes May Hide a Mind-Bending Secret About Our Universe", A blizzard of research in the last decade on the inner lives of black holes has revealed unexpected connections between the two views of the cosmos., , , For the last century the biggest bar fight in science has been between Albert Einstein and himself., , Gravity rules outer space shaping galaxies and indeed the whole universe whereas quantum mechanics rules inner space-the arena of atoms and elementary particles., Quantum entanglement, , Susskind vs Hawking: The Black Hole War,   

    From “The New York Times” : “Black Holes May Hide a Mind-Bending Secret About Our Universe” 

    From “The New York Times”

    10.10.22
    Dennis Overbye

    1
    Credit: Leonardo Santamaria

    For the last century the biggest bar fight in science has been between Albert Einstein and himself.

    On one side is the Einstein who in 1915 conceived General Relativity, which describes gravity as the warping of space-time by matter and energy. That theory predicted that space-time could bend, expand, rip, quiver like a bowl of Jell-O and disappear into those bottomless pits of nothingness known as black holes.

    On the other side is the Einstein who, starting in 1905, laid the foundation for quantum mechanics, the nonintuitive rules that inject randomness into the world — rules that Einstein never accepted. According to quantum mechanics, a subatomic particle like an electron can be anywhere and everywhere at once, and a cat can be both alive and dead until it is observed. God doesn’t play dice, Einstein often complained.

    Gravity rules outer space, shaping galaxies and indeed the whole universe, whereas quantum mechanics rules inner space, the arena of atoms and elementary particles. The two realms long seemed to have nothing to do with each other; this left scientists ill-equipped to understand what happens in an extreme situation like a black hole or the beginning of the universe.

    But a blizzard of research in the last decade on the inner lives of black holes has revealed unexpected connections between the two views of the cosmos. The implications are mind-bending, including the possibility that our three-dimensional universe — and we ourselves — may be holograms, like the ghostly anti-counterfeiting images that appear on some credit cards and drivers licenses. In this version of the cosmos, there is no difference between here and there, cause and effect, inside and outside or perhaps even then and now; household cats can be conjured in empty space. We can all be Dr. Strange.

    “It may be too strong to say that gravity and quantum mechanics are exactly the same thing,” Leonard Susskind of Stanford University wrote in a paper in 2017. “But those of us who are paying attention may already sense that the two are inseparable, and that neither makes sense without the other.”

    That insight, Dr. Susskind and his colleagues hope, could lead to a theory that combines gravity and quantum mechanics — quantum gravity — and perhaps explains how the universe began.

    Einstein vs. Einstein

    The schism between the two Einsteins entered the spotlight in 1935, when the physicist faced off against himself in a pair of scholarly papers.

    In one paper, Einstein and Nathan Rosen showed that general relativity predicted that black holes (which were not yet known by that name) could form in pairs connected by shortcuts through space-time, called Einstein-Rosen bridges — “wormholes.” In the imaginations of science fiction writers, you could jump into one black hole and pop out of the other.

    In the other paper, Einstein, Rosen and another physicist, Boris Podolsky, tried to pull the rug out from quantum mechanics by exposing a seeming logical inconsistency. They pointed out that, according to the uncertainty principle of quantum physics, a pair of particles once associated would be eternally connected, even if they were light-years apart. Measuring a property of one particle — its direction of spin, say — would instantaneously affect the measurement of its mate. If these photons were flipped coins and one came up heads, the other invariably would be found out to be tails.

    To Einstein this proposition was obviously ludicrous, and he dismissed it as “spooky action at a distance.” But today physicists call it “entanglement,” and lab experiments confirm its reality every day. Last week the Nobel Prize in Physics was awarded to a trio of physicists whose experiments over the years had demonstrated the reality of this “spooky action.”

    The physicist N. David Mermin of Cornell University once called such quantum weirdness “the closest thing we have to magic.”

    As Daniel Kabat, a physics professor at Lehman College in New York, explained it, “We’re used to thinking that information about an object — say, that a glass is half-full — is somehow contained within the object. Entanglement means this isn’t correct. Entangled objects don’t have an independent existence with definite properties of their own. Instead they only exist in relation to other objects.”

    Einstein probably never dreamed that the two 1935 papers had anything in common, Dr. Susskind said recently. But Dr. Susskind and other physicists now speculate that wormholes and spooky action are two aspects of the same magic and, as such, are the key to resolving an array of cosmic paradoxes.

    Throwing Dice in the Dark

    To astronomers, black holes are dark monsters with gravity so strong that they can consume stars, wreck galaxies and imprison even light. At the edge of a black hole, time seems to stop. At a black hole’s center, matter shrinks to infinite density and the known laws of physics break down. But to physicists bent on explicating those fundamental laws, black holes are a Coney Island of mysteries and imagination.

    In 1974 the cosmologist Stephen Hawking astonished the scientific world with a heroic calculation showing that, to his own surprise, black holes were neither truly black nor eternal, when quantum effects were added to the picture. Over eons, a black hole would leak energy and subatomic particles, shrink, grow increasingly hot and finally explode. In the process, all the mass that had fallen into the black hole over the ages would be returned to the outer universe as a random fizz of particles and radiation.

    This might sound like good news, a kind of cosmic resurrection. But it was a potential catastrophe for physics. A core tenet of science holds that information is never lost; billiard balls might scatter every which way on a pool table, but in principle it is always possible to rewind the tape to determine where they were in the past or predict their positions in the future, even if they drop into a black hole.

    But if Hawking were correct, the particles radiating from a black hole were random, a meaningless thermal noise stripped of the details of whatever has fallen in. If a cat fell in, most of its information — name, color, temperament — would be unrecoverable, effectively lost from history. It would be as if you opened your safe deposit box and found that your birth certificate and your passport had disappeared. As Hawking phrased it in 1976: “God not only plays dice, he sometimes throws them where they can’t be seen.”

    His declaration triggered a 40-year war of ideas. “This can’t be right,” Dr. Susskind, who became Hawking’s biggest adversary in the subsequent debate, thought to himself when first hearing about Hawking’s claim. “I didn’t know what to make out of it.”

    Encoding Reality

    A potential solution came to Dr. Susskind one day in 1993 as he was walking through a physics building on campus. There in the hallway he saw a display of a hologram of a young woman.

    A hologram is basically a three-dimensional image — a teapot, a cat, Princess Leia — made entirely of light. It is created by illuminating the original (real) object with a laser and recording the patterns of reflected light on a photographic plate. When the plate is later illuminated, a three-dimensional image of the object springs into view at the center.

    “‘Hey, here’s a situation where it looks as if information is kind of reproduced in two different ways,’” Dr. Susskind recalled thinking. On the one hand, there is a visible object that “looked real,” he said. “And on the other hand, there’s the same information coded on the film surrounding the hologram. Up close, it just looks like a little bunch of scratches and a highly complex encoding.”

    The right combinations of scratches on that film, Dr. Susskind realized, could make anything emerge into three dimensions. Then he thought: What if a black hole was actually a hologram, with the event horizon serving as the “film,” encoding what was inside? It was “a nutty idea, a cool idea,” he recalled.

    Across the Atlantic, the same nutty idea had occurred to the Dutch physicist, Gerardus ’t Hooft, a Nobel laureate at Utrecht University in the Netherlands.

    According to Einstein’s general relativity, the information content of a black hole or any three-dimensional space — your living room, say, or the whole universe — was limited to the number of bits that could be encoded on an imaginary surface surrounding it. That space was measured in pixels 10⁻³³ centimeters on a side — the smallest unit of space, known as the Planck length.

    With data pixels so small, this amounted to quadrillions of megabytes per square centimeter — a stupendous amount of information, but not an infinite amount. Trying to cram too much information into any region would cause it to exceed a limit decreed by Jacob Bekenstein, then a Princeton graduate student and Hawking’s rival, and cause it to collapse into a black hole.

    “This is what we found out about Nature’s bookkeeping system,” Dr. ’t Hooft wrote in 1993. “The data can be written onto a surface, and the pen with which the data are written has a finite size.”

    The Soup-Can Universe

    The cosmos-as-holograph idea found its fullest expression a few years later, in 1997. Juan Maldacena, a theorist at the Institute for Advanced Study in Princeton, N.J., used new ideas from string theory — the speculative “theory of everything” that portrays subatomic particles as vibrating strings — to create a mathematical model of the entire universe as a hologram.

    In his formulation, all the information about what happens inside some volume of space is encoded as quantum fields on the surface of the region’s boundary.

    Dr. Maldacena’s universe is often portrayed as a can of soup: Galaxies, black holes, gravity, stars and the rest, including us, are the soup inside, and the information describing them resides on the outside, like a label. Think of it as gravity in a can. The inside and outside of the can — the “bulk” and the “boundary” — are complementary descriptions of the same phenomena.

    Since the fields on the surface of the soup can obey quantum rules about preserving information, the gravitational fields inside the can must also preserve information. In such a picture, “there is no room for information loss,” Dr. Maldacena said at a conference in 2004.

    Hawking conceded: Gravity was not the great eraser after all.

    “In other words, the universe makes sense,” Dr. Susskind said in an interview.

    “It’s completely crazy,” he added, in reference to the holographic universe. “You could imagine in a laboratory, in a sufficiently advanced laboratory, a large sphere — let’s say, a hollow sphere of a specially tailored material — to be made of silicon and other things, with some kind of appropriate quantum fields inscribed on it.” Then you could conduct experiments, he said: Tap on the sphere, interact with it, then wait for answers from the entities inside.

    “On the other hand, you could open up that shell and you would find nothing in it,” he added. As for us entities inside: “We don’t read the hologram, we are the hologram.”

    Wormholes, wormholes everywhere

    Our actual universe, unlike Dr. Maldacena’s mathematical model, has no boundary, no outer limit. Nonetheless, for physicists, his universe became a proof of principle that gravity and quantum mechanics were compatible and offered a font of clues to how our actual universe works.

    But, Dr. Maldacena noted recently, his model did not explain how information manages to escape a black hole intact or how Hawking’s calculation in 1974 went wrong.

    Don Page, a former student of Hawking now at the University of Alberta, took a different approach in the 1990s. Suppose, he said, that information is conserved when a black hole evaporates. If so, then a black hole does not spit out particles as randomly as Hawking had thought. The radiation would start out as random, but as time went on, the particles being emitted would become more and more correlated with those that had come out earlier, essentially filling the gaps in the missing information. After billions and billions of years all the hidden information would have emerged.

    In quantum terms, this explanation required any particles now escaping the black hole to be entangled with the particles that had leaked out earlier. But this presented a problem. Those newly emitted particles were already entangled with their mates that had already fallen into the black hole, running afoul of quantum rules mandating that particles be entangled only in pairs. Dr. Page’s information-transmission scheme could only work if the particles inside the black hole were somehow the same as the particles that were now outside.

    How could that be? The inside and outside of the black hole were connected by wormholes, the shortcuts through space and time proposed by Einstein and Rosen in 1935.

    In 2012 Drs. Maldacena and Susskind proposed a formal truce between the two warring Einsteins. They proposed that spooky entanglement and wormholes were two faces of the same phenomenon. As they put it, employing the initials of the authors of those two 1935 papers, Einstein and Rosen in one and Einstein, Podolsky and Rosen in the other: “ER = EPR.”

    The implication is that, in some strange sense, the outside of a black hole was the same as the inside, like a Klein bottle that has only one side.

    How could information be in two places at once? Like much of quantum physics, the question boggles the mind, like the notion that light can be a wave or a particle depending on how the measurement is made.

    What matters is that, if the interior and exterior of a black hole were connected by wormholes, information could flow through them in either direction, in or out, according to John Preskill, a Caltech physicist and quantum computing expert.

    “We ought to be able to influence the interior of one of these black holes by ‘tickling’ its radiation, and thereby sending a message to the inside of the black hole,” he said in a 2017 interview with Quanta. He added, “It sounds crazy.”

    Ahmed Almheiri, a physicist at N.Y.U. Abu Dhabi, noted recently that by manipulating radiation that had escaped a black hole, he could create a cat inside that black hole. “I can do something with the particles radiating from the black hole, and suddenly a cat is going to appear in the black hole,” he said.

    He added, “We all have to get used to this.”

    The metaphysical turmoil came to a head in 2019. That year two groups of theorists made detailed calculations showing that information leaking through wormholes would match the pattern predicted by Dr. Page. One paper was by Geoff Penington, now at the University of California, Berkeley. And the other was by Netta Engelhardt of M.I.T.; Don Marolf of the University of California, Santa Cruz; Henry Maxfield, now at Stanford University; and Dr. Almheiri. The two groups published their papers on the same day.

    “And so the final moral of the story is, if your theory of gravity includes wormholes, then you get information coming out,” Dr. Penington said. “If it doesn’t include wormholes, then presumably you don’t get information coming out.”

    He added, “Hawking didn’t include wormholes, and we are including wormholes,”

    Not everybody has signed on to this theory. And testing it is a challenge, since particle accelerators will probably never be powerful enough to produce black holes in the lab for study, although several groups of experimenters hope to simulate black holes and wormholes in quantum computers.

    And even if this physics turns out to be accurate, Dr. Mermin’s magic does have an important limit: Neither wormholes nor entanglement can transmit a message, much less a human, faster than the speed of light. So much for time travel. The weirdness only becomes apparent after the fact, when two scientists compare their observations and discover that they match — a process that involves classical physics, which obeys the speed limit set by Einstein.

    As Dr. Susskind likes to say, “You can’t make that cat hop out of a black hole faster than the speed of light.”

    See the full article here .

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  • richardmitnick 4:22 pm on October 7, 2022 Permalink | Reply
    Tags: "Achieving greater entanglement - Milestones on the path to useful quantum technologies", , , , , , Quantum entanglement, ,   

    From The Paderborn University [Universität Paderborn] (DE) Via “phys.org” : “Achieving greater entanglement – Milestones on the path to useful quantum technologies” 

    From The Paderborn University [Universität Paderborn] (DE)

    Via

    “phys.org”

    10.6.22

    1
    a) Operating principle of our approach. Bell pairs are generated sequentially. The detection of one photon triggers the feed-forward including a field programmable gate array (FPGA), which in turn controls the operation mode of an all-optical storage loop. Possible operation modes are “read in and read out” (orange), “Storage” (green), or “PBS interference” (purple) selected by an appropriate switching of the electro-optic modulator (EOM). 2N-fold coincidences confirm the buildup of 2N-photon GHZ states. (b) Sketch of the experimental setup. A Ti:sapphire laser with a wavelength of 775 nm pumps a polarization Bell-state source based on parametric down-conversion in a Sagnac configuration (blue area). One photon of each emitted Bell pair is detected and triggers the feed-forward (red arrows), and the other photon is sent to our all-optical storage loop (green area), where it is stored until it is brought to interference with the subsequent qubit. Credit: Physical Review Letters (2022).

    Tiny particles are interconnected despite sometimes being thousands of kilometers apart—Albert Einstein called this “spooky action at a distance.” Something that would be inexplicable by the laws of classical physics is a fundamental part of quantum physics. Entanglement like this can occur between multiple quantum particles, meaning that certain properties of the particles are intimately linked with each other.

    Entangled systems containing multiple quantum particles offer significant benefits in implementing quantum algorithms, which have the potential to be used in communications, data security or quantum computing. Researchers from Paderborn University have been working with colleagues from Ulm University to develop the first programmable optical quantum memory. The study was published as an “Editor’s suggestion” in the Physical Review Letters journal [below].

    Entangled light particles

    The Integrated Quantum Optics group led by Prof. Christine Silberhorn from the Department of Physics and Institute for Photonic Quantum Systems (PhoQS) at Paderborn University is using minuscule light particles, or photons, as quantum systems. The researchers are seeking to entangle as many as possible in large states. Working together with researchers from the Institute of Theoretical Physics at Ulm University, they have now presented a new approach.

    Previously, attempts to entangle more than two particles only resulted in very inefficient entanglement generation. In some cases, if researchers wanted to link two particles with others, it involved a long wait, as the interconnections that promote this entanglement only operate with limited probability rather than at the touch of a button. This meant that the photons were no longer a part of the experiment once the next suitable particle arrived—as storing qubit states represents a major experimental challenge.

    Gradually achieving greater entanglement

    “We have now developed a programmable, optical, buffer quantum memory that can switch dynamically back and forth between different modes—storage mode, interference mode and the final release,” Silberhorn explains.

    In the experimental setup, a small quantum state can be stored until another state is generated, and then the two can be entangled. This enables a large, entangled quantum state to grow particle by particle. Silberhorn’s team has already used this method to entangle six particles, making it much more efficient than any previous experiments. By comparison, the largest ever entanglement of photon pairs, performed by Chinese researchers, consisted of twelve individual particles. However, creating this state took significantly more time, by orders of magnitude.

    The quantum physicist explains: “Our system allows entangled states of increasing size to be gradually built up—which is much more reliable, faster, and more efficient than any previous method. For us, this represents a milestone that puts us in striking distance of practical applications of large, entangled states for useful quantum technologies.” The new approach can be combined with all common photon-pair sources, meaning that other scientists will also be able to use the method.

    Science paper:
    Physical Review Letters

    See the full article here.

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    The Paderborn University [Universität Paderborn] (DE) is one of the fourteen public research universities in the state of North Rhine-Westphalia in Germany. It was founded in 1972 and 20,308 students were enrolled at the university in the wintersemester 2016/2017. It offers 62 different degree programs.

    The university has several winners of the Gottfried Wilhelm Leibniz Prize awarded by the German Research Foundation (DFG) and ERC grant recipients of the European Research Council. In 2002, the Romanian mathematician Preda Mihăilescu proved the Catalan conjecture, a number-theoretical conjecture, formulated by the French and Belgian mathematician Eugène Charles Catalan, which had stood unresolved for 158 years. The University Closely Collaborates with the Heinz Nixdorf Institute, Paderborn Center for Parallel Computing and two Fraunhofer Institutes for research in Computer Science, Mathematics, Electrical Engineering and Quantum Photonics.

    In 2018, world record for “optical data transmission at 128 gigabits per second” was achieved at the Heinz Nixdorf Institute of the University of Paderborn. The academic ranking of world universities 2018, popularly known as Shanghai Rankings placed the university in the ranking bracket 50-75 among mathematics departments worldwide.

     
  • richardmitnick 9:34 am on October 4, 2022 Permalink | Reply
    Tags: "Nobel Prize in Physics Is Awarded to 3 Scientists for Work in Quantum Technology", , , , Quantum entanglement, , ,   

    From “The New York Times” : “Nobel Prize in Physics Is Awarded to 3 Scientists for Work in Quantum Technology” 

    From “The New York Times”

    10.4.22
    Isabella Kwai
    Cora Engelbrecht
    Dennis Overbye

    1
    Awarding the prize on Tuesday, the committee said that the scientists’ work had “opened doors to another world.” Credit: Jonas Ekstromer/TT News Agency, via Associated Press

    The Nobel Prize in Physics was awarded to Alain Aspect, John F. Clauser and Anton Zeilinger on Tuesday for work that has “laid the foundation for a new era of quantum technology,” the Nobel Committee for Physics said.

    2
    Alain Aspect.

    3
    John F. Clauser

    4
    Anton Zeilinger

    The scientists have each conducted “groundbreaking experiments using entangled quantum states, where two particles behave like a single unit even when they are separated,” the committee said in a briefing. Their results, it said, cleared the way for “new technology based upon quantum information.”

    The laureates’ research builds on the work of John Stewart Bell, a physicist who strove in the 1960s to understand whether particles, having flown too far apart for there to be normal communication between them, can still function in concert, also known as quantum entanglement.

    According to quantum mechanics, particles can exist simultaneously in two or more places. They do not take on formal properties until they are measured or observed in some way. By taking measurements of one particle, like its position or “spin,” a change is observed in its partner, no matter how far away it has traveled from its pair.

    Working independently, the three laureates did experiments that helped clarify a fundamental claim about quantum entanglement, which concerns the behavior of tiny particles, like electrons, that interacted in the past and then moved apart.

    Dr. Clauser, an American, was the first in 1972. Using duct tape and spare parts at The DOE’s Lawrence Berkeley National Laboratory in Berkeley, Calif., he endeavored to measure quantum entanglement by firing thousands of photons in opposite directions to investigate a property known as polarization. When he measured the polarizations of photon pairs, they showed a correlation, proving that a principle called Bell’s inequality had been violated and that the photon pairs were entangled, or acting in concert.

    The research was taken up 10 years later by Dr. Aspect, a French scientist, and his team at the University of Paris. And in 1998, Dr. Zeilinger, an Austrian physicist, led another experiment that considered entanglement among three or more particles.

    Eva Olsson, a member of the Nobel Committee for Physics, noted that quantum information science had broad implications in areas like secure information transfer and quantum computing.

    Quantum information science is a “vibrant and rapidly developing field,” she said. “Its predictions have opened doors to another world, and it has also shaken the very foundation of how we interpret measurements.”

    The Nobel committee said the three scientists were being honored for their experiments with entangled photons, establishing the violation of Bell inequalities and pioneering quantum information science.

    “Being able to manipulate and manage quantum states and all their layers of properties gives us access to tools with unexpected potential,” the committee said in a statement on Twitter.

    Dr. Zeilinger described the award as “an encouragement to young people.”

    “The prize would not be possible without more than 100 young people who worked with me over the years and made all this possible,” he said.

    Though he acknowledged that the award was recognizing the future applications of his work, he said, “My advice would be: Do what you find interesting, and don’t care too much about possible applications.”

    It was the second of several such prizes to be awarded over the coming week. The Nobels, among the highest honors in science, recognize groundbreaking contributions in a variety of fields.

    “I’m still kind of shocked, but it’s a very positive shock,” Dr. Zeilinger said of receiving the phone call informing him of the news.

    See the full article here .

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  • richardmitnick 11:11 am on September 10, 2022 Permalink | Reply
    Tags: "A quantum network of entangled atomic clocks", , , Quantum entanglement, , , This is the first time researchers have been able to achieve this between clocks in two separate remotely entangled systems.   

    From The University of Oxford (UK): “A quantum network of entangled atomic clocks” 

    U Oxford bloc

    From The University of Oxford (UK)

    1

    For the first time, scientists at the University of Oxford have been able to demonstrate a network of two entangled optical atomic clocks and show how the entanglement between the remote clocks can be used to improve their measurement precision, according to research published this week by Nature [below].

    Improving the precision of frequency comparisons between multiple atomic clocks offers the potential to unlock our understanding of all sorts of natural phenomena. It is essential, for example, in measuring the space-time variation of fundamental constants, for geodesy where the frequency of the atomic clocks is used to measure the heights of two locations, and even in the search for dark matter.

    Fundamental limit of precision

    Entanglement – a quantum phenomenon in which two or more particles become linked together so that they can no longer be described independently, even at vast distances – is the key to reaching the fundamental limit of precision that’s determined by quantum theory. While previous experiments have demonstrated that entanglement between clocks in the same system can be used to improve the quality of measurements, this is the first time researchers have been able to achieve this between clocks in two separate remotely entangled systems. This development paves the way for applications like those mentioned above, where comparing the frequencies of atoms in separate locations to the highest possible precision is vital.

    Bethan Nichol, one of the authors of the paper published in Nature, said ‘Thanks to years of hard work from the whole team at Oxford, our network apparatus can produce entangled pairs of ions with high fidelity and high rate at the push of a button. Without this capability this demonstration would not have been possible.’

    State-of-the-art quantum network

    The Oxford team used a state-of-the-art quantum network to achieve their results. Developed by the UK’s Quantum Computing and Simulation (QCS) Hub, a consortium of 17 universities led by the University of Oxford, this network was designed for quantum computing and for communication rather than for quantum-enhanced metrology, but the researchers’ work demonstrates the versatility of such systems. The two clocks used for the experiment were only 2 metres apart, but in principle such networks can be scaled up to cover much larger distances.

    ‘While our result is very much a proof-of-principle, and the absolute precision we achieve is a few orders of magnitude below the state of the art, we hope that the techniques shown here might someday improve state-of the art systems,’ explains Dr Raghavendra Srinivas, another of the paper’s authors. ‘At some point, entanglement will be required as it provides a path to the ultimate precision allowed by quantum theory.’

    Professor David Lucas, whose team at Oxford were responsible for the experiment, said, ‘Our experiment shows the importance of quantum networks for metrology, with applications to fundamental physics, as well as to the more well-known areas of quantum cryptography and quantum computing.’

    Science paper:
    Nature

    See the full article here.

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    U Oxford campus

    The University of Oxford

    1
    Universitas Oxoniensis

    The University of Oxford [a.k.a. The Chancellor, Masters and Scholars of the University of Oxford] is a collegiate research university in Oxford, England. There is evidence of teaching as early as 1096, making it the oldest university in the English-speaking world and the world’s second-oldest university in continuous operation. It grew rapidly from 1167 when Henry II banned English students from attending the University of Paris [Université de Paris](FR). After disputes between students and Oxford townsfolk in 1209, some academics fled north-east to Cambridge where they established what became the The University of Cambridge (UK). The two English ancient universities share many common features and are jointly referred to as Oxbridge.

    The university is made up of thirty-nine semi-autonomous constituent colleges, six permanent private halls, and a range of academic departments which are organised into four divisions. All the colleges are self-governing institutions within the university, each controlling its own membership and with its own internal structure and activities. All students are members of a college. It does not have a main campus, and its buildings and facilities are scattered throughout the city centre. Undergraduate teaching at Oxford consists of lectures, small-group tutorials at the colleges and halls, seminars, laboratory work and occasionally further tutorials provided by the central university faculties and departments. Postgraduate teaching is provided predominantly centrally.

    Oxford operates the world’s oldest university museum, as well as the largest university press in the world and the largest academic library system nationwide. In the fiscal year ending 31 July 2019, the university had a total income of £2.45 billion, of which £624.8 million was from research grants and contracts.

    Oxford has educated a wide range of notable alumni, including 28 prime ministers of the United Kingdom and many heads of state and government around the world. As of October 2020, 72 Nobel Prize laureates, 3 Fields Medalists, and 6 Turing Award winners have studied, worked, or held visiting fellowships at the University of Oxford, while its alumni have won 160 Olympic medals. Oxford is the home of numerous scholarships, including the Rhodes Scholarship, one of the oldest international graduate scholarship programmes.

    The University of Oxford’s foundation date is unknown. It is known that teaching at Oxford existed in some form as early as 1096, but it is unclear when a university came into being.

    It grew quickly from 1167 when English students returned from The University of Paris-Sorbonne [Université de Paris-Sorbonne](FR). The historian Gerald of Wales lectured to such scholars in 1188, and the first known foreign scholar, Emo of Friesland, arrived in 1190. The head of the university had the title of chancellor from at least 1201, and the masters were recognised as a universitas or corporation in 1231. The university was granted a royal charter in 1248 during the reign of King Henry III.

    The students associated together on the basis of geographical origins, into two ‘nations’, representing the North (northerners or Boreales, who included the English people from north of the River Trent and the Scots) and the South (southerners or Australes, who included English people from south of the Trent, the Irish and the Welsh). In later centuries, geographical origins continued to influence many students’ affiliations when membership of a college or hall became customary in Oxford. In addition, members of many religious orders, including Dominicans, Franciscans, Carmelites and Augustinians, settled in Oxford in the mid-13th century, gained influence and maintained houses or halls for students. At about the same time, private benefactors established colleges as self-contained scholarly communities. Among the earliest such founders were William of Durham, who in 1249 endowed University College, and John Balliol, father of a future King of Scots; Balliol College bears his name. Another founder, Walter de Merton, a Lord Chancellor of England and afterwards Bishop of Rochester, devised a series of regulations for college life. Merton College thereby became the model for such establishments at Oxford, as well as at the University of Cambridge. Thereafter, an increasing number of students lived in colleges rather than in halls and religious houses.

    In 1333–1334, an attempt by some dissatisfied Oxford scholars to found a new university at Stamford, Lincolnshire, was blocked by the universities of Oxford and Cambridge petitioning King Edward III. Thereafter, until the 1820s, no new universities were allowed to be founded in England, even in London; thus, Oxford and Cambridge had a duopoly, which was unusual in large western European countries.

    The new learning of the Renaissance greatly influenced Oxford from the late 15th century onwards. Among university scholars of the period were William Grocyn, who contributed to the revival of Greek language studies, and John Colet, the noted biblical scholar.

    With the English Reformation and the breaking of communion with the Roman Catholic Church, recusant scholars from Oxford fled to continental Europe, settling especially at the University of Douai. The method of teaching at Oxford was transformed from the medieval scholastic method to Renaissance education, although institutions associated with the university suffered losses of land and revenues. As a centre of learning and scholarship, Oxford’s reputation declined in the Age of Enlightenment; enrollments fell and teaching was neglected.

    In 1636, William Laud, the chancellor and Archbishop of Canterbury, codified the university’s statutes. These, to a large extent, remained its governing regulations until the mid-19th century. Laud was also responsible for the granting of a charter securing privileges for The University Press, and he made significant contributions to the Bodleian Library, the main library of the university. From the beginnings of the Church of England as the established church until 1866, membership of the church was a requirement to receive the BA degree from the university and “dissenters” were only permitted to receive the MA in 1871.

    The university was a centre of the Royalist party during the English Civil War (1642–1649), while the town favoured the opposing Parliamentarian cause. From the mid-18th century onwards, however, the university took little part in political conflicts.

    Wadham College, founded in 1610, was the undergraduate college of Sir Christopher Wren. Wren was part of a brilliant group of experimental scientists at Oxford in the 1650s, the Oxford Philosophical Club, which included Robert Boyle and Robert Hooke. This group held regular meetings at Wadham under the guidance of the college’s Warden, John Wilkins, and the group formed the nucleus that went on to found the Royal Society.

    Before reforms in the early 19th century, the curriculum at Oxford was notoriously narrow and impractical. Sir Spencer Walpole, a historian of contemporary Britain and a senior government official, had not attended any university. He said, “Few medical men, few solicitors, few persons intended for commerce or trade, ever dreamed of passing through a university career.” He quoted the Oxford University Commissioners in 1852 stating: “The education imparted at Oxford was not such as to conduce to the advancement in life of many persons, except those intended for the ministry.” Nevertheless, Walpole argued:

    “Among the many deficiencies attending a university education there was, however, one good thing about it, and that was the education which the undergraduates gave themselves. It was impossible to collect some thousand or twelve hundred of the best young men in England, to give them the opportunity of making acquaintance with one another, and full liberty to live their lives in their own way, without evolving in the best among them, some admirable qualities of loyalty, independence, and self-control. If the average undergraduate carried from university little or no learning, which was of any service to him, he carried from it a knowledge of men and respect for his fellows and himself, a reverence for the past, a code of honour for the present, which could not but be serviceable. He had enjoyed opportunities… of intercourse with men, some of whom were certain to rise to the highest places in the Senate, in the Church, or at the Bar. He might have mixed with them in his sports, in his studies, and perhaps in his debating society; and any associations which he had this formed had been useful to him at the time, and might be a source of satisfaction to him in after life.”

    Out of the students who matriculated in 1840, 65% were sons of professionals (34% were Anglican ministers). After graduation, 87% became professionals (59% as Anglican clergy). Out of the students who matriculated in 1870, 59% were sons of professionals (25% were Anglican ministers). After graduation, 87% became professionals (42% as Anglican clergy).

    M. C. Curthoys and H. S. Jones argue that the rise of organised sport was one of the most remarkable and distinctive features of the history of the universities of Oxford and Cambridge in the late 19th and early 20th centuries. It was carried over from the athleticism prevalent at the public schools such as Eton, Winchester, Shrewsbury, and Harrow.

    All students, regardless of their chosen area of study, were required to spend (at least) their first year preparing for a first-year examination that was heavily focused on classical languages. Science students found this particularly burdensome and supported a separate science degree with Greek language study removed from their required courses. This concept of a Bachelor of Science had been adopted at other European universities (The University of London (UK) had implemented it in 1860) but an 1880 proposal at Oxford to replace the classical requirement with a modern language (like German or French) was unsuccessful. After considerable internal wrangling over the structure of the arts curriculum, in 1886 the “natural science preliminary” was recognized as a qualifying part of the first-year examination.

    At the start of 1914, the university housed about 3,000 undergraduates and about 100 postgraduate students. During the First World War, many undergraduates and fellows joined the armed forces. By 1918 virtually all fellows were in uniform, and the student population in residence was reduced to 12 per cent of the pre-war total. The University Roll of Service records that, in total, 14,792 members of the university served in the war, with 2,716 (18.36%) killed. Not all the members of the university who served in the Great War were on the Allied side; there is a remarkable memorial to members of New College who served in the German armed forces, bearing the inscription, ‘In memory of the men of this college who coming from a foreign land entered into the inheritance of this place and returning fought and died for their country in the war 1914–1918’. During the war years the university buildings became hospitals, cadet schools and military training camps.

    Reforms

    Two parliamentary commissions in 1852 issued recommendations for Oxford and Cambridge. Archibald Campbell Tait, former headmaster of Rugby School, was a key member of the Oxford Commission; he wanted Oxford to follow the German and Scottish model in which the professorship was paramount. The commission’s report envisioned a centralised university run predominantly by professors and faculties, with a much stronger emphasis on research. The professional staff should be strengthened and better paid. For students, restrictions on entry should be dropped, and more opportunities given to poorer families. It called for an enlargement of the curriculum, with honours to be awarded in many new fields. Undergraduate scholarships should be open to all Britons. Graduate fellowships should be opened up to all members of the university. It recommended that fellows be released from an obligation for ordination. Students were to be allowed to save money by boarding in the city, instead of in a college.

    The system of separate honour schools for different subjects began in 1802, with Mathematics and Literae Humaniores. Schools of “Natural Sciences” and “Law, and Modern History” were added in 1853. By 1872, the last of these had split into “Jurisprudence” and “Modern History”. Theology became the sixth honour school. In addition to these B.A. Honours degrees, the postgraduate Bachelor of Civil Law (B.C.L.) was, and still is, offered.

    The mid-19th century saw the impact of the Oxford Movement (1833–1845), led among others by the future Cardinal John Henry Newman. The influence of the reformed model of German universities reached Oxford via key scholars such as Edward Bouverie Pusey, Benjamin Jowett and Max Müller.

    Administrative reforms during the 19th century included the replacement of oral examinations with written entrance tests, greater tolerance for religious dissent, and the establishment of four women’s colleges. Privy Council decisions in the 20th century (e.g. the abolition of compulsory daily worship, dissociation of the Regius Professorship of Hebrew from clerical status, diversion of colleges’ theological bequests to other purposes) loosened the link with traditional belief and practice. Furthermore, although the university’s emphasis had historically been on classical knowledge, its curriculum expanded during the 19th century to include scientific and medical studies. Knowledge of Ancient Greek was required for admission until 1920, and Latin until 1960.

    The University of Oxford began to award doctorates for research in the first third of the 20th century. The first Oxford D.Phil. in mathematics was awarded in 1921.

    The mid-20th century saw many distinguished continental scholars, displaced by Nazism and communism, relocating to Oxford.

    The list of distinguished scholars at the University of Oxford is long and includes many who have made major contributions to politics, the sciences, medicine, and literature. As of October 2020, 72 Nobel laureates and more than 50 world leaders have been affiliated with the University of Oxford.

    To be a member of the university, all students, and most academic staff, must also be a member of a college or hall. There are thirty-nine colleges of the University of Oxford (including Reuben College, planned to admit students in 2021) and six permanent private halls (PPHs), each controlling its membership and with its own internal structure and activities. Not all colleges offer all courses, but they generally cover a broad range of subjects.

    The colleges are:

    All-Souls College
    Balliol College
    Brasenose College
    Christ Church College
    Corpus-Christi College
    Exeter College
    Green-Templeton College
    Harris-Manchester College
    Hertford College
    Jesus College
    Keble College
    Kellogg College
    Lady-Margaret-Hall
    Linacre College
    Lincoln College
    Magdalen College
    Mansfield College
    Merton College
    New College
    Nuffield College
    Oriel College
    Pembroke College
    Queens College
    Reuben College
    St-Anne’s College
    St-Antony’s College
    St-Catherines College
    St-Cross College
    St-Edmund-Hall College
    St-Hilda’s College
    St-Hughs College
    St-John’s College
    St-Peters College
    Somerville College
    Trinity College
    University College
    Wadham College
    Wolfson College
    Worcester College

    The permanent private halls were founded by different Christian denominations. One difference between a college and a PPH is that whereas colleges are governed by the fellows of the college, the governance of a PPH resides, at least in part, with the corresponding Christian denomination. The six current PPHs are:

    Blackfriars
    Campion Hall
    Regent’s Park College
    St Benet’s Hall
    St-Stephen’s Hall
    Wycliffe Hall

    The PPHs and colleges join as the Conference of Colleges, which represents the common concerns of the several colleges of the university, to discuss matters of shared interest and to act collectively when necessary, such as in dealings with the central university. The Conference of Colleges was established as a recommendation of the Franks Commission in 1965.

    Teaching members of the colleges (i.e. fellows and tutors) are collectively and familiarly known as dons, although the term is rarely used by the university itself. In addition to residential and dining facilities, the colleges provide social, cultural, and recreational activities for their members. Colleges have responsibility for admitting undergraduates and organizing their tuition; for graduates, this responsibility falls upon the departments. There is no common title for the heads of colleges: the titles used include Warden, Provost, Principal, President, Rector, Master and Dean.

    Oxford is regularly ranked within the top 5 universities in the world and is currently ranked first in the world in the Times Higher Education World University Rankings, as well as the Forbes’s World University Rankings. It held the number one position in The Times Good University Guide for eleven consecutive years, and the medical school has also maintained first place in the “Clinical, Pre-Clinical & Health” table of The Times Higher Education World University Rankings for the past seven consecutive years. In 2021, it ranked sixth among the universities around the world by SCImago Institutions Rankings. The Times Higher Education has also recognised Oxford as one of the world’s “six super brands” on its World Reputation Rankings, along with The University of California-Berkeley, The University of Cambridge (UK), Harvard University, The Massachusetts Institute of Technology, and Stanford University. The university is fifth worldwide on the US News ranking. Its Saïd Business School came 13th in the world in The Financial Times Global MBA Ranking.
    Oxford was ranked ninth in the world in 2015 by The Nature Index, which measures the largest contributors to papers published in 82 leading journals. It is ranked fifth best university worldwide and first in Britain for forming CEOs according to The Professional Ranking World Universities, and first in the UK for the quality of its graduates as chosen by the recruiters of the UK’s major companies.

    In the 2018 Complete University Guide, all 38 subjects offered by Oxford rank within the top 10 nationally meaning Oxford was one of only two multi-faculty universities (along with Cambridge) in the UK to have 100% of their subjects in the top 10. Computer Science, Medicine, Philosophy, Politics and Psychology were ranked first in the UK by the guide.

    According to The QS World University Rankings by Subject, the University of Oxford also ranks as number one in the world for four Humanities disciplines: English Language and Literature, Modern Languages, Geography, and History. It also ranks second globally for Anthropology, Archaeology, Law, Medicine, Politics & International Studies, and Psychology.

     
  • richardmitnick 10:51 am on September 10, 2022 Permalink | Reply
    Tags: "AMO": atomic molecular and optical physics program, "Purdue researchers suggest novel way to generate a light source made from entangled photons", "XUV': extreme-ultraviolet wavelengths, , , , , , Quantum entanglement, , The team proposed a method to generate entangled photons at extreme-ultraviolet (XUV) wavelengths where no such source currently exists., This research shows promise in establishing the measurement of entangled photons down to the attosecond and possibly even zeptosecond.   

    From Purdue University: “Purdue researchers suggest novel way to generate a light source made from entangled photons” 

    From Purdue University

    9.7.22

    Cheryl Pierce,
    Communications Specialist
    pierce81@purdue.edu

    1
    In a recent publication in Physical Review Research, Purdue researchers propose an unconventional way to generate light made from entangled photons. In the graphic above, photons meet the electrons of a helium atom, which then emits two entangled photons. Graphic by: Cheryl Pierce with elements from Adobe Stock.

    This research shows promise in establishing the measurement of entangled photons down to the attosecond and possibly even zeptosecond.

    Entanglement is a strange phenomenon in quantum physics where two particles are inherently connected to each other no matter the distance between them. When one is measured, the other measurement is instantly a given. Researchers from Purdue University have proposed a novel, unconventional approach to generate a special light source made up of entangled photons. On Sept. 6, 2022, they published their findings in Physical Review Research [below].

    The team proposed a method to generate entangled photons at extreme-ultraviolet (XUV) wavelengths where no such source currently exists. Their work provides a road map on how to generate these entangled photons and use them to track the dynamics of electrons in molecules and materials on the incredibly short timescales of attoseconds.

    “The entangled photons in our work are guaranteed to arrive at a given location within a very short duration of attoseconds, as long as they travel the same distance,” says Dr. Niranjan Shivaram, assistant professor of Physics and Astronomy. “This correlation in their arrival time makes them very useful to measure ultrafast events. One important application is in attosecond metrology to push the limits of measurement of the shortest time scale phenomena. This source of entangled photons can also be used in quantum imaging and spectroscopy, where entangled photons have been shown to enhance the ability to gain information, but now at XUV and even X-ray wavelengths.”

    The authors of the publication are all from the Purdue University Department of Physics and Astronomy and work with the Purdue Quantum Science and Engineering Institute (PQSEI). They are Dr. Yimeng Wang, recent graduate of Purdue University; Siddhant Pandey, PhD candidate in the field of experimental ultrafast spectroscopy; Dr. Chris H. Greene, Albert Overhauser Distinguished Professor of Physics and Astronomy; and Dr. Shivaram.

    “The Department of Physics and Astronomy at Purdue has a strong atomic, molecular and optical (AMO) physics program, which brings together experts in various subfields of AMO,” says Shivaram. “Chris Greene’s expert knowledge of theoretical atomic physics combined with Niranjan’s background in the relatively young field of experimental attosecond science led to this collaborative project. While many universities have AMO programs, Purdue’s AMO program is uniquely diverse in that it has experts in multiple subfields of AMO science.”

    Each researcher played a significant role in this ongoing research. Greene initially suggested the idea of using photons emitted by helium atoms as a source of entangled photons and Shivaram suggested applications to attosecond science and proposed experimental schemes. Wang and Greene then developed the theoretical framework to calculate entangled photon emission from helium atoms, while Pandey and Shivaram made estimates of entangled photon emission/absorption rates and worked out the details of the proposed attosecond experimental schemes.

    The publication marks the beginning of this research for Shivaram and Greene. In this publication, the authors propose the idea and work out the theoretical aspects of the experiment. Shivaram and Greene plan to continue to collaborate on experimental and further theoretical ideas. Shivaram’s lab, the Ultrafast Quantum Dynamics Group, is currently building an apparatus to experimentally demonstrate some of these ideas. According to Shivaram, the hope is that other researchers in attosecond science will begin working on these ideas. A concerted effort by many research groups could further increase the impact of this work. Eventually, they hope to get the timescale of entangled photons down to the zeptosecond, 10^-21 seconds.

    “Typically, experiments on attosecond timescales are performed using attosecond laser pulses as ‘strobes’ to ‘image’ the electrons. Current limits on these pulses are around 40 attoseconds. Our proposed idea of using entangled photons could push this down to a few attoseconds or zeptoseconds,” says Shivaram.

    In order to understand the timing, one must understand that electrons play a fundamental role in determining the behavior of atoms, molecules and solid materials. The timescale of motion of electrons is typically in the femtosecond (one millionth of a billionth of a second – 10^-15 seconds) and attosecond (one billionth of a billionth of a second, or 10^-18 seconds) scale. According to Shivaram, gaining insight into the dynamics of electrons and tracking their motion on these ultrashort timescales is essential.

    “The goal of the field of ultrafast science is to make such ‘movies’ of electrons and then use light to control the behavior of these electrons to engineer chemical reactions, make materials with novel properties, make molecular-scale devices, etc.,” he says. “This is light-matter interaction at its most basic level, and the possibilities for discovery are many. A single zeptosecond is 10^-21 seconds. A thousand zeptoseconds is an attosecond. Researchers are only now beginning to explore zeptosecond phenomena, though it is experimentally out of reach due to lack of zeptosecond laser pulses. Our unique approach of using entangled photons instead of photons in laser pulses could allow us to reach the zeptosecond regime. This will require considerable experimental effort and is likely possible on the timescale of five years.”

    Science paper:
    Physical Review Research

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Purdue University is a public land-grant research university in West Lafayette, Indiana, and the flagship campus of the Purdue University system. The university was founded in 1869 after Lafayette businessman John Purdue donated land and money to establish a college of science, technology, and agriculture in his name. The first classes were held on September 16, 1874, with six instructors and 39 students.

    The main campus in West Lafayette offers more than 200 majors for undergraduates, over 69 masters and doctoral programs, and professional degrees in pharmacy and veterinary medicine. In addition, Purdue has 18 intercollegiate sports teams and more than 900 student organizations. Purdue is a member of the Big Ten Conference and enrolls the second largest student body of any university in Indiana, as well as the fourth largest foreign student population of any university in the United States.

    Purdue University is a member of the Association of American Universities and is classified among “R1: Doctoral Universities – Very high research activity”. Purdue has 25 American astronauts as alumni and as of April 2019, the university has been associated with 13 Nobel Prizes.

    In 1865, the Indiana General Assembly voted to take advantage of the Morrill Land-Grant Colleges Act of 1862 and began plans to establish an institution with a focus on agriculture and engineering. Communities throughout the state offered facilities and funding in bids for the location of the new college. Popular proposals included the addition of an agriculture department at Indiana State University, at what is now Butler University. By 1869, Tippecanoe County’s offer included $150,000 (equivalent to $2.9 million in 2019) from Lafayette business leader and philanthropist John Purdue; $50,000 from the county; and 100 acres (0.4 km^2) of land from local residents.

    On May 6, 1869, the General Assembly established the institution in Tippecanoe County as Purdue University, in the name of the principal benefactor. Classes began at Purdue on September 16, 1874, with six instructors and 39 students. Professor John S. Hougham was Purdue’s first faculty member and served as acting president between the administrations of presidents Shortridge and White. A campus of five buildings was completed by the end of 1874. In 1875, Sarah A. Oren, the State Librarian of Indiana, was appointed Professor of Botany.

    Purdue issued its first degree, a Bachelor of Science in chemistry, in 1875, and admitted its first female students that autumn.

    Emerson E. White, the university’s president, from 1876 to 1883, followed a strict interpretation of the Morrill Act. Rather than emulate the classical universities, White believed Purdue should be an “industrial college” and devote its resources toward providing a broad, liberal education with an emphasis on science, technology, and agriculture. He intended not only to prepare students for industrial work, but also to prepare them to be good citizens and family members.

    Part of White’s plan to distinguish Purdue from classical universities included a controversial attempt to ban fraternities, which was ultimately overturned by the Indiana Supreme Court, leading to White’s resignation. The next president, James H. Smart, is remembered for his call in 1894 to rebuild the original Heavilon Hall “one brick higher” after it had been destroyed by a fire.

    By the end of the nineteenth century, the university was organized into schools of agriculture, engineering (mechanical, civil, and electrical), and pharmacy; former U.S. President Benjamin Harrison served on the board of trustees. Purdue’s engineering laboratories included testing facilities for a locomotive, and for a Corliss steam engine—one of the most efficient engines of the time. The School of Agriculture shared its research with farmers throughout the state, with its cooperative extension services, and would undergo a period of growth over the following two decades. Programs in education and home economics were soon established, as well as a short-lived school of medicine. By 1925, Purdue had the largest undergraduate engineering enrollment in the country, a status it would keep for half a century.

    President Edward C. Elliott oversaw a campus building program between the world wars. Inventor, alumnus, and trustee David E. Ross coordinated several fundraisers, donated lands to the university, and was instrumental in establishing the Purdue Research Foundation. Ross’s gifts and fundraisers supported such projects as Ross–Ade Stadium, the Memorial Union, a civil engineering surveying camp, and Purdue University Airport. Purdue Airport was the country’s first university-owned airport and the site of the country’s first college-credit flight training courses.

    Amelia Earhart joined the Purdue faculty in 1935 as a consultant for these flight courses and as a counselor on women’s careers. In 1937, the Purdue Research Foundation provided the funds for the Lockheed Electra 10-E Earhart flew on her attempted round-the-world flight.

    Every school and department at the university was involved in some type of military research or training during World War II. During a project on radar receivers, Purdue physicists discovered properties of germanium that led to the making of the first transistor. The Army and the Navy conducted training programs at Purdue and more than 17,500 students, staff, and alumni served in the armed forces. Purdue set up about a hundred centers throughout Indiana to train skilled workers for defense industries. As veterans returned to the university under the G.I. Bill, first-year classes were taught at some of these sites to alleviate the demand for campus space. Four of these sites are now degree-granting regional campuses of the Purdue University system. On-campus housing became racially desegregated in 1947, following pressure from Purdue President Frederick L. Hovde and Indiana Governor Ralph F. Gates.

    After the war, Hovde worked to expand the academic opportunities at the university. A decade-long construction program emphasized science and research. In the late 1950s and early 1960s the university established programs in veterinary medicine, industrial management, and nursing, as well as the first computer science department in the United States. Undergraduate humanities courses were strengthened, although Hovde only reluctantly approved of graduate-level study in these areas. Purdue awarded its first Bachelor of Arts degrees in 1960. The programs in liberal arts and education, formerly administered by the School of Science, were soon split into an independent school.

    The official seal of Purdue was officially inaugurated during the university’s centennial in 1969.

    1

    Consisting of elements from emblems that had been used unofficially for 73 years, the current seal depicts a griffin, symbolizing strength, and a three-part shield, representing education, research, and service.

    In recent years, Purdue’s leaders have continued to support high-tech research and international programs. In 1987, U.S. President Ronald Reagan visited the West Lafayette campus to give a speech about the influence of technological progress on job creation.

    In the 1990s, the university added more opportunities to study abroad and expanded its course offerings in world languages and cultures. The first buildings of the Discovery Park interdisciplinary research center were dedicated in 2004.

    Purdue launched a Global Policy Research Institute in 2010 to explore the potential impact of technical knowledge on public policy decisions.

    On April 27, 2017, Purdue University announced plans to acquire for-profit college Kaplan University and convert it to a public university in the state of Indiana, subject to multiple levels of approval. That school now operates as Purdue University Global, and aims to serve adult learners.

    Campuses

    Purdue’s campus is situated in the small city of West Lafayette, near the western bank of the Wabash River, across which sits the larger city of Lafayette. State Street, which is concurrent with State Road 26, divides the northern and southern portions of campus. Academic buildings are mostly concentrated on the eastern and southern parts of campus, with residence halls and intramural fields to the west, and athletic facilities to the north. The Greater Lafayette Public Transportation Corporation (CityBus) operates eight campus loop bus routes on which students, faculty, and staff can ride free of charge with Purdue Identification.

    Organization and administration

    The university president, appointed by the board of trustees, is the chief administrative officer of the university. The office of the president oversees admission and registration, student conduct and counseling, the administration and scheduling of classes and space, the administration of student athletics and organized extracurricular activities, the libraries, the appointment of the faculty and conditions of their employment, the appointment of all non-faculty employees and the conditions of employment, the general organization of the university, and the planning and administration of the university budget.

    The Board of Trustees directly appoints other major officers of the university including a provost who serves as the chief academic officer for the university, several vice presidents with oversight over specific university operations, and the regional campus chancellors.

    Academic divisions

    Purdue is organized into thirteen major academic divisions.

    College of Agriculture

    The university’s College of Agriculture supports the university’s agricultural, food, life, and natural resource science programs. The college also supports the university’s charge as a land-grant university to support agriculture throughout the state; its agricultural extension program plays a key role in this.

    College of Education

    The College of Education offers undergraduate degrees in elementary education, social studies education, and special education, and graduate degrees in these and many other specialty areas of education. It has two departments: (a) Curriculum and Instruction and (b) Educational Studies.

    College of Engineering

    The Purdue University College of Engineering was established in 1874 with programs in Civil and Mechanical Engineering. The college now offers B.S., M.S., and Ph.D. degrees in more than a dozen disciplines. Purdue’s engineering program has also educated 24 of America’s astronauts, including Neil Armstrong and Eugene Cernan who were the first and last astronauts to have walked on the Moon, respectively. Many of Purdue’s engineering disciplines are recognized as top-ten programs in the U.S. The college as a whole is currently ranked 7th in the U.S. of all doctorate-granting engineering schools by U.S. News & World Report.

    Exploratory Studies

    The university’s Exploratory Studies program supports undergraduate students who enter the university without having a declared major. It was founded as a pilot program in 1995 and made a permanent program in 1999.

    College of Health and Human Sciences

    The College of Health and Human Sciences was established in 2010 and is the newest college. It offers B.S., M.S. and Ph.D. degrees in all 10 of its academic units.

    College of Liberal Arts

    Purdue’s College of Liberal Arts contains the arts, social sciences and humanities programs at the university. Liberal arts courses have been taught at Purdue since its founding in 1874. The School of Science, Education, and Humanities was formed in 1953. In 1963, the School of Humanities, Social Sciences, and Education was established, although Bachelor of Arts degrees had begun to be conferred as early as 1959. In 1989, the School of Liberal Arts was created to encompass Purdue’s arts, humanities, and social sciences programs, while education programs were split off into the newly formed School of Education. The School of Liberal Arts was renamed the College of Liberal Arts in 2005.

    Krannert School of Management

    The Krannert School of Management offers management courses and programs at the undergraduate, master’s, and doctoral levels.

    College of Pharmacy

    The university’s College of Pharmacy was established in 1884 and is the 3rd oldest state-funded school of pharmacy in the United States. The school offers two undergraduate programs leading to the B.S. in Pharmaceutical Sciences (BSPS) and the Doctor of Pharmacy (Pharm.D.) professional degree. Graduate programs leading to M.S. and Ph.D. degrees are offered in three departments (Industrial and Physical Pharmacy, Medicinal Chemistry and Molecular Pharmacology, and Pharmacy Practice). Additionally, the school offers several non-degree certificate programs and post-graduate continuing education activities.

    Purdue Polytechnic Institute

    The Purdue Polytechnic Institute offers bachelor’s, master’s and Ph.D. degrees in a wide range of technology-related disciplines. With over 30,000 living alumni, it is one of the largest technology schools in the United States.

    College of Science

    The university’s College of Science houses the university’s science departments: Biological Sciences; Chemistry; Computer Science; Earth, Atmospheric, & Planetary Sciences; Mathematics; Physics & Astronomy; and Statistics. The science courses offered by the college account for about one-fourth of Purdue’s one million student credit hours.

    College of Veterinary Medicine

    The College of Veterinary Medicine is accredited by the AVMA to offer the Doctor of Veterinary Medicine degree, associate’s and bachelor’s degrees in veterinary technology, master’s and Ph.D. degrees, and residency programs leading to specialty board certification. Within the state of Indiana, the Purdue University College of Veterinary Medicine is the only veterinary school, while the Indiana University School of Medicine is one of only two medical schools (the other being Marian University College of Osteopathic Medicine). The two schools frequently collaborate on medical research projects.

    Honors College

    Purdue’s Honors College supports an honors program for undergraduate students at the university.

    The Graduate School

    The university’s Graduate School supports graduate students at the university.

    Research

    The university expended $622.814 million in support of research system-wide in 2017, using funds received from the state and federal governments, industry, foundations, and individual donors. The faculty and more than 400 research laboratories put Purdue University among the leading research institutions. Purdue University is considered by the Carnegie Classification of Institutions of Higher Education to have “very high research activity”. Purdue also was rated the nation’s fourth best place to work in academia, according to rankings released in November 2007 by The Scientist magazine. Purdue’s researchers provide insight, knowledge, assistance, and solutions in many crucial areas. These include, but are not limited to Agriculture; Business and Economy; Education; Engineering; Environment; Healthcare; Individuals, Society, Culture; Manufacturing; Science; Technology; Veterinary Medicine. The Global Trade Analysis Project (GTAP), a global research consortium focused on global economic governance challenges (trade, climate, resource use) is also coordinated by the University. Purdue University generated a record $438 million in sponsored research funding during the 2009–10 fiscal year with participation from National Science Foundation, National Aeronautics and Space Administration, and the Department of Agriculture, Department of Defense, Department of Energy, and Department of Health and Human Services. Purdue University was ranked fourth in Engineering research expenditures amongst all the colleges in the United States in 2017, with a research expenditure budget of 244.8 million. Purdue University established the Discovery Park to bring innovation through multidisciplinary action. In all of the eleven centers of Discovery Park, ranging from entrepreneurship to energy and advanced manufacturing, research projects reflect a large economic impact and address global challenges. Purdue University’s nanotechnology research program, built around the new Birck Nanotechnology Center in Discovery Park, ranks among the best in the nation.

    The Purdue Research Park which opened in 1961 was developed by Purdue Research Foundation which is a private, nonprofit foundation created to assist Purdue. The park is focused on companies operating in the arenas of life sciences, homeland security, engineering, advanced manufacturing and information technology. It provides an interactive environment for experienced Purdue researchers and for private business and high-tech industry. It currently employs more than 3,000 people in 155 companies, including 90 technology-based firms. The Purdue Research Park was ranked first by the Association of University Research Parks in 2004.

    Purdue’s library system consists of fifteen locations throughout the campus, including an archives and special collections research center, an undergraduate library, and several subject-specific libraries. More than three million volumes, including one million electronic books, are held at these locations. The Library houses the Amelia Earhart Collection, a collection of notes and letters belonging to Earhart and her husband George Putnam along with records related to her disappearance and subsequent search efforts. An administrative unit of Purdue University Libraries, Purdue University Press has its roots in the 1960 founding of Purdue University Studies by President Frederick Hovde on a $12,000 grant from the Purdue Research Foundation. This was the result of a committee appointed by President Hovde after the Department of English lamented the lack of publishing venues in the humanities. Since the 1990s, the range of books published by the Press has grown to reflect the work from other colleges at Purdue University especially in the areas of agriculture, health, and engineering. Purdue University Press publishes print and ebook monograph series in a range of subject areas from literary and cultural studies to the study of the human-animal bond. In 1993 Purdue University Press was admitted to membership of the Association of American University Presses. Purdue University Press publishes around 25 books a year and 20 learned journals in print, in print & online, and online-only formats in collaboration with Purdue University Libraries.

    Sustainability

    Purdue’s Sustainability Council, composed of University administrators and professors, meets monthly to discuss environmental issues and sustainability initiatives at Purdue. The University’s first LEED Certified building was an addition to the Mechanical Engineering Building, which was completed in Fall 2011. The school is also in the process of developing an arboretum on campus. In addition, a system has been set up to display live data detailing current energy production at the campus utility plant. The school holds an annual “Green Week” each fall, an effort to engage the Purdue community with issues relating to environmental sustainability.

    Rankings

    In its 2021 edition, U.S. News & World Report ranked Purdue University the 5th most innovative national university, tied for the 17th best public university in the United States, tied for 53rd overall, and 114th best globally. U.S. News & World Report also rated Purdue tied for 36th in “Best Undergraduate Teaching, 83rd in “Best Value Schools”, tied for 284th in “Top Performers on Social Mobility”, and the undergraduate engineering program tied for 9th at schools whose highest degree is a doctorate.

     
  • richardmitnick 10:50 pm on September 2, 2022 Permalink | Reply
    Tags: "New Fur for the Quantum Cat. Quantum materials:: entanglement of many atoms discovered for the first time", , , , , , Quantum entanglement, , , , , The scientists discovered an entirely new type of quantum phase transitions where entanglement takes place on the scale of many thousands of atoms instead of just in the microcosm of only a few.,   

    From The Dresden University of Technology [Technische Universität Dresden] (DE) And The Technical University of Munich [Technische Universität München] (DE): “New Fur for the Quantum Cat. Quantum materials:: entanglement of many atoms discovered for the first time” 

    From The Dresden University of Technology [Technische Universität Dresden] (DE)

    And

    Techniche Universitat Munchen

    The Technical University of Munich [Technische Universität München] (DE)

    9.2.22
    Prof. Matthias Vojta
    Technische Universität Dresden
    Chair of Theoretical Solid State Physics
    Cluster of Excellence ct.qmat – Complexity and Topology in Quantum Matter
    Co-spokesperson
    Tel.: +49 351 463-34135
    Matthias.Vojta@tu-dresden.de

    1
    Schroedinger’s cat with quantum fur: In the material LiHoF4, physicists from the universities of Dresden and Munich have discovered a new quantum phase transition at which the domains behave in a quantum mechanical fashion. Credit: C. Hohmann, MCQST.

    Be it magnets or superconductors: materials are known for their various properties. However, these properties may change spontaneously under extreme conditions. Researchers at the Technische Universität Dresden (TUD) and the Technische Universität München (TUM) have discovered an entirely new type of such phase transitions. They display the phenomenon of quantum entanglement involving many atoms, which previously has only been observed in the realm of few atoms. The results were recently published in the scientific journal Nature [below].

    New Fur for the Quantum Cat

    In physics, Schroedinger’s cat is an allegory for two of the most awe-inspiring effects of quantum mechanics: entanglement and superposition. Researchers from Dresden and Munich have now observed these behaviors on a much larger scale than that of the smallest of particles. Until now, materials that display properties like, e.g., magnetism have been known to have so-called domains – islands in which the materials properties are homogeneously either of one or a different kind (imagine them being either black or white, for example). Looking at lithium holmium fluoride (LiHoF4), the physicists have now discovered a completely new phase transition, at which the domains surprisingly exhibit quantum mechanical features, resulting in their properties becoming entangled (being black and white at the same time). “Our quantum cat now has a new fur because we’ve discovered a new quantum phase transition in LiHoF4 which has not previously been known to exist,” comments Matthias Vojta, Chair of Theoretical Solid State Physics at TUD.

    Phase transitions and entanglement

    We can easily observe the spontaneously changing properties of a substance if we look at water: at 100 degrees Celsius it evaporates into a gas, at zero degrees Celsius it freezes into ice. In both cases, these new states of matter form as a consequence of a phase transition where the water molecules rearrange themselves, thus changing the characteristics of the matter. Properties like magnetism or superconductivity emerge as a result of electrons undergoing phase transitions in crystals. For phase transitions at temperatures approaching the absolute zero at -273.15 degrees Celsius, quantum mechanical effects such as entanglement come into play, and one speaks of quantum phase transitions. “Even though there are more than 30 years of extensive research dedicated to phase transitions in quantum materials, we had previously assumed that the phenomenon of entanglement played a role only on a microscopic scale, where it involves only a few atoms at a time,” explains Christian Pfleiderer, Professor of Topology of Correlated Systems at the TUM.

    Quantum entanglement is one of the most astonishing phenomena of physics, where the entangled quantum particles exist in a shared superposition state that allows for usually mutually exclusive properties (e.g., black and white) to occur simultaneously. As a rule, the laws of quantum mechanics only apply to microscopic particles. The research teams from Munich and Dresden have now succeeded in observing effects of quantum entanglement on a much larger scale, that of thousands of atoms. For this, they have chosen to work with the well-known compound LiHoF4.

    Spherical samples enable precision measurements

    At very low temperatures, LiHoF4 acts as a ferromagnet where all magnetic moments spontaneously point in the same direction. If you then apply a magnetic field exactly vertically to the preferred magnetic direction, the magnetic moments will change direction, which is known as fluctuations. The higher the magnetic field strength, the stronger these fluctuations become, until, eventually, the ferromagnetism disappears completely at a quantum phase transition. This leads to the entanglement of neighboring magnetic moments. “If you hold up a LiHoF4 sample to a very strong magnet, it suddenly ceases to be spontaneously magnetic. This has been known for 25 years,” summarizes Vojta.

    What is new is what happens when you change the direction of the magnetic field. “We discovered that the quantum phase transition continues to occur, whereas it had previously been believed that even the smallest tilt of the magnetic field would immediately suppress it,” explains Pfleiderer. Under these conditions, however, it is not individual magnetic moments but rather extensive magnetic areas, so-called ferromagnetic domains, that undergo these quantum phase transitions. The domains constitute entire islands of magnetic moments pointing in the same direction. “We have used spherical samples for our precision measurements. That is what enabled us to precisely study the behavior upon small changes in the direction of the magnetic field,” adds Andreas Wendl, who conducted the experiments as part of his doctoral dissertation.

    From fundamental physics to applications

    “We have discovered an entirely new type of quantum phase transitions where entanglement takes place on the scale of many thousands of atoms instead of just in the microcosm of only a few,” explains Vojta. “If you imagine the magnetic domains as a black-and-white pattern, the new phase transition leads to either the white or the black areas becoming infinitesimally small, i.e., creating a quantum pattern, bevor dissolving completely.” A newly developed theoretical model successfully explains the data obtained from the experiments. “For our analysis, we generalized existing microscopic models and also took into account the feedback of the large ferromagnetic domains to the microscopic properties,” elaborates Heike Eisenlohr, who performed the calculations as part of her PhD thesis.

    The discovery of the new quantum phase transitions is important as a foundation and general frame of reference for the research of quantum phenomena in materials, as well as for new applications. “Quantum entanglement is applied and used in technologies like quantum sensors and quantum computers, amongst other things,” says Vojta. Pfleiderer adds: “Our work is in the area of fundamental research, which, however, can have a direct impact on the development of practical applications, if you use the materials properties in a controlled way.”

    Science paper:
    Nature

    See the full article here.

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     Technische Universität München Campus

    The Technical University of Munich [Technische Universität München] (DE) is a public research university in Munich, with additional campuses in Garching, Freising, Heilbronn, Straubing, and Singapore. A technical university that specializes in engineering, technology, medicine, and the applied and natural sciences, it is organized into 11 schools and departments, and supported by numerous research centers.

    A University of Excellence under the German Universities Excellence Initiative, TUM is consistently ranked among the leading universities in the European Union and its researchers and alumni include 16 Nobel laureates and 23 Leibniz Prize winners.

    Departments

    Aerospace engineering, geodesy
    Ottobrunn

    Department of Architecture
    Munich

    Department of Civil, Geo and Environmental Engineering
    Civil engineering, environmental engineering, earth science
    Munich

    Department of Chemistry
    Garching

    Department of Electrical and Computer Engineering
    Munich

    Department of Informatics [Computer science]
    Garching

    Department of Mechanical Engineering
    Garching

    Department of Mathematics
    Garching

    School of Medicine
    Munich

    Department of Physics
    Garching

    Department of Sport and Health Sciences
    Munich

    School of Education
    Munich

    School of Governance
    Munich

    School of Management
    Munich

    School of Life Sciences
    Freising

    Research

    The Technical University of Munich is one of the most research-focused universities in Europe. This claim is supported by relevant rankings, such as the funding ranking of the German Research Foundation and the research ranking of the Centre for Higher Education.

    Under the German Universities Excellence Initiative, TUM has obtained funding for multiple research clusters, including e-conversion (energy technology), MCQST – Munich Center for Quantum Science and Technology(DE) (quantum mechanics), ORIGINS (astrophysics, biophysics and particle physics), and SYNERGY (neurology).

    In addition to the schools and departments, TUM has set up numerous research centers with external cooperation partners.

    Integrative research centers (IRCs) combine research with teaching. They include the TUM Institute for Advanced Study (TUM-IAS), the TUM-Munich Center for Technology in Society (MCTS), TUM-Munich Data Science Institute (MDSI), TUM-Munich School of Engineering , TUM-Munich Institute of Biomedical Engineering, and the TUM-Munich Institute of Robotics and Machine Intelligence.

    Corporate research centers (CRCs) carry out research independently of the schools and departments, cooperating with industry partners for application-driven research. They include the research reactor FRM II, the Center for Functional Protein Assemblies (CPA), the Catalysis Research Center (CRC), the center for translational Cancer Research (TranslaTUM), the Walter Schottky Institute (WSI), the Hans Eisenmann-Zentrum for Agricultural Science, and the Institute for Food & Health (ZIEL).

    Rankings

    TUM is ranked first in Germany in the fields of engineering and computer science, and within the top three in the natural sciences.

    In the QS World Rankings, TUM is ranked 19th (worldwide) in engineering and technology, 28th in the natural sciences, 29th in computer science, and 50th place overall. It is the highest ranked German university in those subject areas.

    In the Times Higher Education World University Rankings, TUM stands at 38th place worldwide and 2nd place nationwide. Worldwide, it ranks 14th in computer science, 22nd in engineering and technology, and 23rd in the physical sciences. It is the highest ranked German university in those subject areas.

    In the Academic Ranking of World Universities, TUM is ranked at 52nd place in the world and 2nd place in Germany. In the subject areas of computer science and engineering, electrical engineering, aerospace engineering, food science, biotechnology, and chemistry, TUM is ranked first in Germany.

    In the 2021 Global University Employability Ranking of the Times Higher Education World Rankings, TUM was ranked 13th in the world and 4th in Europe. TUM is ranked 7th overall in Reuters’ 2019 European Most Innovative University ranking.

    The TUM School of Management is triple accredited by the European Quality Improvement System (EQUIS), the Association to Advance Collegiate Schools of Business (AACSB) and the Association of MBAs (AMBA).

    Partnerships

    TUM has over 160 international partnerships, ranging from joint research activities to international study programs. Partners include:

    Europe: ETH Zurich, EPFL, ENSEA, École Centrale Paris, TU Eindhoven, Technical University of Denmark, and Technical University of Vienna
    United States:The Massachusetts Institute of Technology , Stanford University, Northwestern University, University of Illinois, Cornell University, University of Texas-Austin, and Georgia Tech
    Asia: The National University of Singapore, Multimedia University, Hong Kong University of Science and Technology, Huazhong University of Science and Technology, Tsinghua University, University of Tokyo, Indian Institute of Technology Delhi, Amrita University, and Sirindhorn International Institute of Technology.
    Australia: Australian National University, University of Melbourne, The Royal Melbourne Institute of Technology (AU).

    Through the Erasmus+ program and its international student exchange program TUMexchange, TUM students are provided by opportunities to study abroad.e, TUM students are provided by opportunities to study abroad.

    The Dresden University of Technology [Technische Universität Dresden] (DE) is a public research university, the largest institute of higher education in the city of Dresden, the largest university in Saxony and one of the 10 largest universities in Germany with 32,389 students as of 2018.

    The name Technische Universität Dresden has only been used since 1961; the history of the university, however, goes back nearly 200 years to 1828. This makes it one of the oldest colleges of technology in Germany, and one of the country’s oldest universities, which in German today refers to institutes of higher education that cover the entire curriculum. The university is a member of TU9, a consortium of the nine leading German Institutes of Technology. The university is one of eleven German universities which succeeded in the Excellence Initiative in 2012, thus getting the title of a “University of Excellence”. The TU Dresden succeeded in all three rounds of the German Universities Excellence Initiative (Future Concept, Graduate Schools, Clusters of Excellence).

    History

    In 1828, with emerging industrialization, the “Saxon Technical School” was founded to educate skilled workers in technological subjects such as mechanics; mechanical engineering and ship construction. In 1871 the year the German Empire was founded, the institute was renamed the Royal Saxon Polytechnic Institute (Königlich-Sächsisches Polytechnikum). At that time, subjects not connected with technology such as history and languages were introduced. By the end of the 19th century the institute had developed into a university covering all disciplines. In 1961 it was given its present name, Dresden University of Technology [Technische Universität Dresden].

    Upon German reunification in 1990 the university had already integrated the College of Forestry (Forstliche Hochschule) formerly the Royal Saxony Academy of Forestry, in the nearby small town of Tharandt. This was followed by the integration of the Dresden College of Engineering (Ingenieurshochschule Dresden); the Friedrich List College of Transport (Hochschule für Verkehrswesen) the faculty of transport science; and the “Carl-Gustav Carus” Medical Academy (Medizinische Akademi), the medical faculty. Some faculties were newly founded: the faculties of Information Technology (1991); Law (1991); Education (1993); and Economics (1993).

    In 2009 TU Dresden, all Dresden institutes of the Fraunhofer Society; the Gottfried Wilhelm Leibniz Scientific Community and the Max Planck Society and Forschungszentrum Dresden-Rossendorf soon incorporated into the Helmholtz Association of German Research Centres (DE), published a joint letter of intent with the name DRESDEN-Konzept – Dresden Research and Education Synergies for the Development of Excellence and Novelty, which points out worldwide elite aspirations, which was recognized as the first time that all four big post-gradual elite institutions declared campus co-operation with a university.

    Sciences

    With 4,390 students the Faculty of Mathematics and the Natural Sciences is the second-largest faculty at the university. It is composed of 5 departments: Biology; Chemistry; Mathematics; Physics; and Psychology. The departments are all located on the main campus. In 2006, a new research building for the biology department opened. In October 2006 the Deutsche Forschungsgemeinschaft decided to fund a new graduate school, the Dresden International Graduate School for Biomedicine and Bioengineering and a so-called cluster of excellence From Cells to Tissues to Therapies.

    Engineering

    The Faculty of Architecture comprises 6 departments. Currently, there are 1,410 students enrolled.
    The Faculty of Civil Engineering is structured into 11 departments. It is the oldest and smallest of the faculties. There are currently 800 students enrolled.
    The Faculty of Computer Science comprises six departments: Applied Computer Science; Artificial Intelligence; Software- and Multimedia-Technology; Systems Architecture; Computer Engineering; and Theoretical Computer Science. The faculty has 2,703 students.
    The Faculty of Electrical Engineering and Information Technology is organized into 13 departments. There are 2,288 students enrolled. The faculty is the heart of the so-called Silicon Saxony in Dresden.
    The Faculty of Environmental Sciences has 2,914 students. The faculty is located on the main campus, except for the Forestry department which is located in Tharandt. The Forestry department is the oldest of its kind in Germany. Its history goes back to the foundation of the Royal Saxon Academy of Forestry (Königlich-Sächsische Forstakademie) in 1816.
    The Faculty of Mechanical Engineering comprises 19 departments and has 5,731 students. It is the largest faculty at TUD.
    The Faculty of Transport and Traffic Sciences “Friedrich List” is the only of its kind in Germany covering transport and traffic from economy and system theory science to electrical, civil and mechanical engineering. There are 1,536 students enrolled.

    Humanities and Social Sciences

    The Faculty of Business and Economics comprises five departments: Business Education Studies (Wirtschaftspädagogik); Business Management; Economics; Business Information Systems; and Statistics. There are 2,842 students enrolled.
    The Faculty of Education, located East of the main campus, has 2,075 students.
    The Faculty of Languages, Literature and Culture is structured into five departments: American Studies; English Studies; German Studies; Philology; Romance Languages; and Slavic Studies. There are 3,215 students at this faculty.
    The Faculty of Law is going to close in the next few years. Currently there are still 933 students enrolled. The TU Dresden has partially compensated the closure by establishing a private law school
    The Faculty of Philosophy comprises seven departments: Art History; Communications; History; Musicology; Political Sciences; Sociology; and Theology. There are 3,485 students enrolled.
    The School of International Studies is a so-called central institution of the university coordinating the law, economics and political sciences departments for courses of interdisciplinary international relations.

    Medicine
    The Carl Gustav Carus Faculty of Medicine has its own campus East of the city center near the Elbe river. Currently, there are 2,195 students enrolled. The faculty has a partnership with Partners Harvard Medical International.

    Research Centers
    Center for Advancing Electronics Dresden (cfaed) – Cluster of Excellence
    Center for Regenerative Therapies Dresden (CRTD) – Cluster of Excellence
    Dendro-Institute Tharandt at the TU Dresden
    The European Institute for Postgraduate Education at TU Dresden (EIPOS Europäisches Institut für postgraduale Bildung an der Technischen Universität Dresden e. V.)
    The European Institute of Transport (EVI Europäisches Verkehrsinstitut an der Technischen Universität Dresden e. V.)
    The Hannah Arendt Center for Research on Totalitarianism (HAIT Hannah-Arendt-Institut für Totalitarismusforschung an der Technischen Universität Dresden e. V.)
    Center for Media Culture (MKZ Medienkulturzentrum Dresden e. V. an der TU Dresden)
    Center for Research on Mechanics of Structures and Materials (SWM Struktur- und Werkstoffmechanikforschung Dresden GmbH an der Technischen Universität Dresden)
    TUD Vietnam ERC, the TU Dresden Vietnam Education and Research Center. The center offers a Master’s course in Mechatronics in Hanoi (Vietnam) since 2004.
    Center for Continuing Education in Historic Preservation (WBD Weiterbildungszentrum für Denkmalpflege und Altbauinstandsetzung e. V.)
    School of International Studies (Zentrum für Internationale Studien, ZIS in German)

     
  • richardmitnick 8:32 pm on August 25, 2022 Permalink | Reply
    Tags: "Entangled photons tailor-made", , , Creating a basis for a new type of quantum computer., It was possible to create a chain of up to 14 light particles that were entangled with each other by the atomic rotations and brought into a desired state., , , Physicists at the Max Planck Institute of Quantum Optics have managed to entangle more than a dozen photons efficiently and in a defined way., , , Quantum entanglement, , The method used by the Garching team allows basically any number of entangled photons to be generated., The MPG Institute for Quantum Optics [MPG Institut für Quantenoptik] (DE), The researchers generated up to 14 entangled photons in an optical resonator.   

    From The MPG Institute for Quantum Optics [MPG Institut für Quantenoptik] (DE) : “Entangled photons tailor-made” 

    Max Planck Institut für Quantenoptik (DE)

    From The MPG Institute for Quantum Optics [MPG Institut für Quantenoptik] (DE)

    8.25.22

    Philip Thomas
    PhD Candidate +49 89 32905-515
    philip.thomas@mpq.mpg.de
    Max Planck Institute of Quantum Optics

    Katharina Jarrah
    PR and Communications
    +49 89 32905-213
    katharina.jarrah@mpg.mpg.de
    Max Planck Institute of Quantum Optics

    Physicists at the Max Planck Institute of Quantum Optics have managed to entangle more than a dozen photons efficiently and in a defined way. They are thus creating a basis for a new type of quantum computer.

    1
    A single rubidium atom is trapped in an optical resonator consisting of two highly reflective mirrors. Repeated excitation of the atom causes several entangled single photons to be emitted in succession.

    In order to effectively use a quantum computer, a larger number of specially prepared – in technical terms: entangled – basic building blocks are needed to carry out computational operations. A team of physicists at the Max Planck Institute of Quantum Optics in Garching has now for the very first time demonstrated this task with photons emitted by a single atom. Following a novel technique, the researchers generated up to 14 entangled photons in an optical resonator, which can be prepared into specific quantum physical states in a targeted and very efficient manner. The new method could facilitate the construction of powerful and robust quantum computers, and serve the secure transmission of data in the future.

    The phenomena of the quantum world, which often seem bizarre from the perspective of the common everyday world, have long since found their way into technology. For example, entanglement: a quantum-physical connection between particles that links them in a strange way over arbitrarily long distances. It can be used, for example, in a quantum computer – a computing machine that, unlike a conventional computer, can perform numerous mathematical operations simultaneously. However, in order to use a quantum computer profitably, a large number of entangled particles must work together. They are the basic elements for calculations, so-called qubits.

    “Photons, the particles of light, are particularly well suited for this because they are robust by nature and easy to manipulate,” says Philip Thomas, a doctoral student at the Max Planck Institute of Quantum Optics (MPQ) in Garching near Munich. Together with colleagues from the Quantum Dynamics Division led by Prof. Gerhard Rempe, he has now succeeded in taking an important step towards making photons usable for technological applications such as quantum computing: For the first time, the team generated up to 14 entangled photons in a defined way and with high efficiency.

    One atom as a photon source

    “The trick to this experiment was that we used a single atom to emit the photons and interweave them in a very specific way,” says Thomas. To do this, the Max Planck researchers placed a rubidium atom at the center of an optical cavity – a kind of echo chamber for electromagnetic waves. With laser light of a certain frequency, the state of the atom could be precisely addressed. Using an additional control pulse, the researchers also specifically triggered the emission of a photon that is entangled with the quantum state of the atom.

    “We repeated this process several times and in a previously determined manner,” Thomas reports. In between, the atom was manipulated in a certain way – in technical jargon: rotated. In this way, it was possible to create a chain of up to 14 light particles that were entangled with each other by the atomic rotations and brought into a desired state. “To the best of our knowledge, the 14 interconnected light particles are the largest number of entangled photons that have been generated in the laboratory so far,” Thomas emphasizes.

    2
    Setup of an optical resonator in a vacuum. A single rubidium atom is trapped between the conically shaped mirrors inside the holder.

    Deterministic generation process

    But it is not only the quantity of entangled photons that marks a major step towards the development of powerful quantum computers – the way they are generated is also very different from conventional methods. “Because the chain of photons emerged from a single atom, it could be produced in a deterministic way,” Thomas explains. This means: in principle, each control pulse actually delivers a photon with the desired properties. Until now, the entanglement of photons usually took place in special, non-linear crystals. The shortcoming: there, the light particles are essentially created randomly and in a way that cannot be controlled. This also limits the number of particles that can be bundled into a collective state.

    The method used by the Garching team, on the other hand, allows basically any number of entangled photons to be generated. In addition, the method is particularly efficient – another important measure for possible future technical applications: “By measuring the photon chain produced, we were able to prove an efficiency of almost 50 percent,” says Philip Thomas. This means: almost every second “push of a button” on the rubidium atom delivered a usable light particle – far more than has been achieved in previous experiments. “All in all, our work removes a long-standing obstacle on the path to scalable, measurement-based quantum computing,” summarizes department Director Gerhard Rempe the results.

    More space for quantum communication

    3
    Experimental setup with vacuum chamber on an optical table.

    The scientists at the MPQ want to remove yet another hurdle. Complex computing operations for instance would require at least two atoms as photon sources in the resonator. The quantum physicists speak of a two-dimensional cluster state. “We are already working on tackling this task,” reveals Philip Thomas. The Max Planck researcher also emphasises that possible technical applications extend far beyond quantum computing: “Another application example is quantum communication” – the tap-proof transmission of information, for example by light in an optical fibre. There, the light experiences unavoidable losses during its propagation due to optical effects such as scattering and absorption – which limits the distance over which data can be transported. Using the method developed in Garching, quantum information could be packaged in entangled photons and could also survive a certain amount of light loss – and enable secure communication over greater distances.

    Science paper:
    Nature

    See the full article here .

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    Research at the The MPG Institute for Quantum Optics [MPG Institut für Quantenoptik ] (DE)

    Light can behave as an electromagnetic wave or a shower of particles that have no mass, called photons, depending on the conditions under which it is studied or used. Matter, on the other hand, is composed of particles, but it can actually exhibit wave-like properties, giving rise to many astonishing phenomena in the microcosm.

    At our institute we explore the interaction of light and quantum systems, exploiting the two extreme regimes of the wave-particle duality of light and matter. On the one hand we handle light at the single photon level where wave-interference phenomena differ from those of intense light beams. On the other hand, when cooling ensembles of massive particles down to extremely low temperatures we suddenly observe phenomena that go back to their wave-like nature. Furthermore, when dealing with ultrashort and highly intense light pulses comprising trillions of photons we can completely neglect the particle properties of light. We take advantage of the large force that the rapidly oscillating electromagnetic field exerts on electrons to steer their motion within molecules or accelerate them to relativistic energies.

    Science paper:
    Nature

    The MPG Society for the Advancement of Science [MPG Gesellschaft zur Förderung der Wissenschaften e. V.] is a formally independent non-governmental and non-profit association of German research institutes founded in 1911 as the Kaiser Wilhelm Society and renamed the Max Planck Society in 1948 in honor of its former president, theoretical physicist Max Planck. The society is funded by the federal and state governments of Germany as well as other sources.

    According to its primary goal, the MPG Society supports fundamental research in the natural, life and social sciences, the arts and humanities in its 83 (as of January 2014) MPG Institutes. The society has a total staff of approximately 17,000 permanent employees, including 5,470 scientists, plus around 4,600 non-tenured scientists and guests. Society budget for 2015 was about €1.7 billion.

    The MPG Institutes focus on excellence in research. The MPG Society has a world-leading reputation as a science and technology research organization, with 33 Nobel Prizes awarded to their scientists, and is generally regarded as the foremost basic research organization in Europe and the world. In 2013, the Nature Publishing Index placed the MPG institutes fifth worldwide in terms of research published in Nature journals (after Harvard University, The Massachusetts Institute of Technology, Stanford University and The National Institutes of Health). In terms of total research volume (unweighted by citations or impact), the Max Planck Society is only outranked by The Chinese Academy of Sciences [中国科学院](CN), The Russian Academy of Sciences [Росси́йская акаде́мия нау́к](RU) and Harvard University. The Thomson Reuters-Science Watch website placed the MPG Society as the second leading research organization worldwide following Harvard University, in terms of the impact of the produced research over science fields.

    The MPG Society and its predecessor Kaiser Wilhelm Society hosted several renowned scientists in their fields, including Otto Hahn, Werner Heisenberg, and Albert Einstein.

    History

    The organization was established in 1911 as the Kaiser Wilhelm Society, or Kaiser-Wilhelm-Gesellschaft (KWG), a non-governmental research organization named for the then German emperor. The KWG was one of the world’s leading research organizations; its board of directors included scientists like Walther Bothe, Peter Debye, Albert Einstein, and Fritz Haber. In 1946, Otto Hahn assumed the position of President of KWG, and in 1948, the society was renamed the Max Planck Society (MPG) after its former President (1930–37) Max Planck, who died in 1947.

    The MPG Society has a world-leading reputation as a science and technology research organization. In 2006, the Times Higher Education Supplement rankings of non-university research institutions (based on international peer review by academics) placed the MPG Society as No.1 in the world for science research, and No.3 in technology research (behind AT&T Corporation and The DOE’s Argonne National Laboratory.

    The domain mpg.de attracted at least 1.7 million visitors annually by 2008 according to a Compete.com study.

    MPG Institutes and research groups

    The MPG Society consists of over 80 research institutes. In addition, the society funds a number of Max Planck Research Groups (MPRG) and International Max Planck Research Schools (IMPRS). The purpose of establishing independent research groups at various universities is to strengthen the required networking between universities and institutes of the Max Planck Society.
    The research units are primarily located across Europe with a few in South Korea and the U.S. In 2007, the Society established its first non-European centre, with an institute on the Jupiter campus of Florida Atlantic University (US) focusing on neuroscience.
    The MPG Institutes operate independently from, though in close cooperation with, the universities, and focus on innovative research which does not fit into the university structure due to their interdisciplinary or transdisciplinary nature or which require resources that cannot be met by the state universities.

    Internally, MPG Institutes are organized into research departments headed by directors such that each MPI has several directors, a position roughly comparable to anything from full professor to department head at a university. Other core members include Junior and Senior Research Fellows.

    In addition, there are several associated institutes:

    International Max Planck Research Schools

    Together with the Association of Universities and other Education Institutions in Germany, the Max Planck Society established numerous International Max Planck Research Schools (IMPRS) to promote junior scientists:

    • Cologne Graduate School of Ageing Research, Cologne
    • International Max Planck Research School for Intelligent Systems, at the Max Planck Institute for Intelligent Systems located in Tübingen and Stuttgart
    • International Max Planck Research School on Adapting Behavior in a Fundamentally Uncertain World (Uncertainty School), at the Max Planck Institutes for Economics, for Human Development, and/or Research on Collective Goods
    • International Max Planck Research School for Analysis, Design and Optimization in Chemical and Biochemical Process Engineering, Magdeburg
    • International Max Planck Research School for Astronomy and Cosmic Physics, Heidelberg at the MPI for Astronomy
    • International Max Planck Research School for Astrophysics, Garching at the MPI for Astrophysics
    • International Max Planck Research School for Complex Surfaces in Material Sciences, Berlin
    • International Max Planck Research School for Computer Science, Saarbrücken
    • International Max Planck Research School for Earth System Modeling, Hamburg
    • International Max Planck Research School for Elementary Particle Physics, Munich, at the MPI for Physics
    • International Max Planck Research School for Environmental, Cellular and Molecular Microbiology, Marburg at the Max Planck Institute for Terrestrial Microbiology
    • International Max Planck Research School for Evolutionary Biology, Plön at the Max Planck Institute for Evolutionary Biology
    • International Max Planck Research School “From Molecules to Organisms”, Tübingen at the Max Planck Institute for Developmental Biology
    • International Max Planck Research School for Global Biogeochemical Cycles, Jena at the Max Planck Institute for Biogeochemistry
    • International Max Planck Research School on Gravitational Wave Astronomy, Hannover and Potsdam MPI for Gravitational Physics
    • International Max Planck Research School for Heart and Lung Research, Bad Nauheim at the Max Planck Institute for Heart and Lung Research
    • International Max Planck Research School for Infectious Diseases and Immunity, Berlin at the Max Planck Institute for Infection Biology
    • International Max Planck Research School for Language Sciences, Nijmegen
    • International Max Planck Research School for Neurosciences, Göttingen
    • International Max Planck Research School for Cognitive and Systems Neuroscience, Tübingen
    • International Max Planck Research School for Marine Microbiology (MarMic), joint program of the Max Planck Institute for Marine Microbiology in Bremen, the University of Bremen, the Alfred Wegener Institute for Polar and Marine Research in Bremerhaven, and the Jacobs University Bremen
    • International Max Planck Research School for Maritime Affairs, Hamburg
    • International Max Planck Research School for Molecular and Cellular Biology, Freiburg
    • International Max Planck Research School for Molecular and Cellular Life Sciences, Munich
    • International Max Planck Research School for Molecular Biology, Göttingen
    • International Max Planck Research School for Molecular Cell Biology and Bioengineering, Dresden
    • International Max Planck Research School Molecular Biomedicine, program combined with the ‘Graduate Programm Cell Dynamics And Disease’ at the University of Münster and the Max Planck Institute for Molecular Biomedicine
    • International Max Planck Research School on Multiscale Bio-Systems, Potsdam
    • International Max Planck Research School for Organismal Biology, at the University of Konstanz and the Max Planck Institute for Ornithology
    • International Max Planck Research School on Reactive Structure Analysis for Chemical Reactions (IMPRS RECHARGE), Mülheim an der Ruhr, at the Max Planck Institute for Chemical Energy Conversion
    • International Max Planck Research School for Science and Technology of Nano-Systems, Halle at Max Planck Institute of Microstructure Physics
    • International Max Planck Research School for Solar System Science at the University of Göttingen hosted by MPI for Solar System Research
    • International Max Planck Research School for Astronomy and Astrophysics, Bonn, at the MPI for Radio Astronomy (formerly the International Max Planck Research School for Radio and Infrared Astronomy)
    • International Max Planck Research School for the Social and Political Constitution of the Economy, Cologne
    • International Max Planck Research School for Surface and Interface Engineering in Advanced Materials, Düsseldorf at Max Planck Institute for Iron Research GmbH
    • International Max Planck Research School for Ultrafast Imaging and Structural Dynamics, Hamburg

    Max Planck Schools

    • Max Planck School of Cognition
    • Max Planck School Matter to Life
    • Max Planck School of Photonics

    Max Planck Center

    • The Max Planck Centre for Attosecond Science (MPC-AS), POSTECH Pohang
    • The Max Planck POSTECH Center for Complex Phase Materials, POSTECH Pohang

    Max Planck Institutes

    Among others:
    • Max Planck Institute for Neurobiology of Behavior – caesar, Bonn
    • Max Planck Institute for Aeronomics in Katlenburg-Lindau was renamed to Max Planck Institute for Solar System Research in 2004;
    • Max Planck Institute for Biology in Tübingen was closed in 2005;
    • Max Planck Institute for Cell Biology in Ladenburg b. Heidelberg was closed in 2003;
    • Max Planck Institute for Economics in Jena was renamed to the Max Planck Institute for the Science of Human History in 2014;
    • Max Planck Institute for Ionospheric Research in Katlenburg-Lindau was renamed to Max Planck Institute for Aeronomics in 1958;
    • Max Planck Institute for Metals Research, Stuttgart
    • Max Planck Institute of Oceanic Biology in Wilhelmshaven was renamed to Max Planck Institute of Cell Biology in 1968 and moved to Ladenburg 1977;
    • Max Planck Institute for Psychological Research in Munich merged into the Max Planck Institute for Human Cognitive and Brain Sciences in 2004;
    • Max Planck Institute for Protein and Leather Research in Regensburg moved to Munich 1957 and was united with the Max Planck Institute for Biochemistry in 1977;
    • Max Planck Institute for Virus Research in Tübingen was renamed as Max Planck Institute for Developmental Biology in 1985;
    • Max Planck Institute for the Study of the Scientific-Technical World in Starnberg (from 1970 until 1981 (closed)) directed by Carl Friedrich von Weizsäcker and Jürgen Habermas.
    • Max Planck Institute for Behavioral Physiology
    • Max Planck Institute of Experimental Endocrinology
    • Max Planck Institute for Foreign and International Social Law
    • Max Planck Institute for Physics and Astrophysics
    • Max Planck Research Unit for Enzymology of Protein Folding
    • Max Planck Institute for Biology of Ageing

     
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