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  • richardmitnick 12:50 pm on April 28, 2018 Permalink | Reply
    Tags: , , , , , , , Quantum entanglement, , Thermodynamics   

    From Kavli Institute for the Physics and Mathematics of the Universe: “Study Finds Way to Use Quantum Entanglement to Study Black Holes” 

    KavliFoundation

    The Kavli Foundation

    Kavli IPMU
    Kavli IMPU

    April 23, 2018

    A team of researchers has found a relationship between quantum physics, the study of very tiny phenomena, to thermodynamics, the study of very large phenomena, reports a new study this week in Nature Communications.

    “Our function can describe a variety of systems from quantum states in electrons to, in principle, black holes,” says study author Masataka Watanabe.

    Quantum entanglement is a phenomenon fundamental to quantum mechanics, where two separated regions share the same information. It is invaluable to a variety of applications including being used as a resource in quantum computation, or quantifying the amount of information stored in a black hole.

    Quantum mechanics is known to preserve information, while thermal equilibrium seems to lose some part of it, and so understanding the relationship between these microscopic and macroscopic concepts is important. So a group of graduate students and a researcher at the University of Tokyo, including the Kavli Institute for the Physics and Mathematics of the Universe, investigated the role of the quantum entanglement in thermal equilibrium in an isolated quantum system.

    1
    Figure 1: Graph showing quantum entanglement and spatial distribution. When separating matter A and B, the vertical axis shows how much quantum entanglement there is, while the horizontal axis shows the length of matter A. (Credit: Nakagawa et al.)

    “A pure quantum state stabilizing into thermal equilibrium can be compared to water being poured into a cup. In a quantum-mechanical system, the colliding water molecules create quantum entanglements, and these quantum entanglements will eventually lead a cup of water to thermal equilibrium. However, it has been a challenge to develop a theory which predicts how much quantum entanglement was inside because lots of quantum entanglements are created in complicated manners at thermal equilibrium,” says Watanabe.

    In their study, the team identified a function predicting the spatial distribution of information stored in an equilibrated system, and they revealed that it was determined by thermodynamic entropy alone. Also, by carrying out computer simulations, they found that the spatial distribution remained the same regardless of what systems were used and regardless of how they reached thermal equilibrium.

    See the full article here .

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    Kavli IPMU (Kavli Institute for the Physics and Mathematics of the Universe) is an international research institute with English as its official language. The goal of the institute is to discover the fundamental laws of nature and to understand the Universe from the synergistic perspectives of mathematics, astronomy, and theoretical and experimental physics. The Institute for the Physics and Mathematics of the Universe (IPMU) was established in October 2007 under the World Premier International Research Center Initiative (WPI) of the Ministry of Education, Sports, Science and Technology in Japan with the University of Tokyo as the host institution. IPMU was designated as the first research institute within the University of Tokyo Institutes for Advanced Study (UTIAS) in January 2011. It received an endowment from The Kavli Foundation and was renamed the “Kavli Institute for the Physics and Mathematics of the Universe” in April 2012. Kavli IPMU is located on the Kashiwa campus of the University of Tokyo, and more than half of its full-time scientific members come from outside Japan. http://www.ipmu.jp/
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    The Kavli Foundation, based in Oxnard, California, is dedicated to the goals of advancing science for the benefit of humanity and promoting increased public understanding and support for scientists and their work.

    The Foundation’s mission is implemented through an international program of research institutes, professorships, and symposia in the fields of astrophysics, nanoscience, neuroscience, and theoretical physics as well as prizes in the fields of astrophysics, nanoscience, and neuroscience.

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  • richardmitnick 10:19 am on April 5, 2018 Permalink | Reply
    Tags: A New State of Quantum Matter Has Been Found in a Material Scientists Thought Was All Chaos, , Photoemission electron microscopy, Quantum entanglement, , , , Shakti geometry, Spin ice   

    From Science Alert: “A New State of Quantum Matter Has Been Found in a Material Scientists Thought Was All Chaos” 

    ScienceAlert

    Science Alert

    5 APR 2018
    MIKE MCRAE

    1
    (enot-poloskun/istock)

    What else is lurking in there?

    Experiments carried out on a complex arrangement of magnetic particles have identified a completely new state of matter, and it can only be explained if scientists turn to quantum physics.

    The messy structures behind the research show strange properties that could allow us to study the chaos of exotic particles – if researchers can find order in there, it could help us understand these particles in greater detail, opening up a whole new landscape for quantum technology.

    Physicists from the US carried out their research on the geometrical arrangements of particles in a weird material known as spin ice.

    Like common old water ice, the particles making up spin ice sort themselves into geometric patterns as the temperature drops.

    There are a number of compounds that can be used to build this kind of material, but they all share the same kind of quantum property – their individual magnetic ‘spin’ sets up a bias in how the particles point to one another, creating complex structures.

    So, unlike the predictable crystalline patterns in water ice, the nanoscale magnetic particles making up spin ice can look disordered and chaotic under certain conditions, flipping back and forth wildly.

    The researchers focussed on one particular structure called a Shakti geometry, and measured how its magnetic arrangements fluctuated with changes in temperature.

    States of matter are usually broken down into categories such as solid, liquid, and gas. We’re taught on a fundamental level that a material’s volume and fluidity can change with shifts in its temperature and pressure.

    But there’s another way to think of a state of matter – by considering the points at which there’s a dramatic change in the way particles arrange themselves as they gain or lose energy.

    For example, the freezing of water is one such dramatic change – a sudden restructuring that occurs as pure water is chilled below 0 degrees Celsius (32 degrees Fahrenheit), where its molecules lose the energy they need to remain free and adopt another stable configuration.

    When researchers slowly lowered the temperature on spin ice arranged in a Shakti geometry, they got it to produce a similar behaviour – one that has never been seen before in other forms of spin ice.

    Using a process called photoemission electron microscopy, the team was then able to image the changes in pattern based on how their electrons emitted light.

    They were noticing points at which a specific arrangement persisted even as the temperature continued to drop.

    “The system gets stuck in a way that it cannot rearrange itself, even though a large-scale rearrangement would allow it to fall to a lower energy state,” says senior researcher Peter Schiffer, currently at Yale University.

    Such a ‘sticking point’ is a hallmark of a state of matter, and one that wasn’t expected in the flip-flopping madness of spin ice.

    Most states of matter can be described fairly efficiently using classical models of thermodynamics, with jiggling particles overcoming binding forces as they swap heat energy.

    In this case there was no clear model describing what was balancing the changes in energy with the material’s stable arrangement.

    So the team applied a quantum touch, looking at how entanglement between particles aligned to give rise to a particular topology, or pattern within a changing space.

    “Our research shows for the first time that classical systems such as artificial spin ice can be designed to demonstrate topological ordered phases, which previously have been found only in quantum conditions,” says physicist Cristiano Nisoli from Los Alamos National Laboratory.

    Ten years ago, quasiparticles that behaved like magnetic monopoles [Nature] were observed in another type of spin ice, also pointing at a weird kind of phase transition.

    Quasiparticles are becoming big things in our search for new kinds of matter that behaves in odd but useful ways, as they have pontential to be used in quantum computing. So having better models for understanding this quantum landscape will no doubt come in handy.

    This research was published in Nature.

    See the full article here .

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  • richardmitnick 2:15 pm on March 12, 2018 Permalink | Reply
    Tags: A possible experiment to prove that gravity and quantum mechanics can be reconciled, , , , , Quantum entanglement,   

    From phys.org: “A possible experiment to prove that gravity and quantum mechanics can be reconciled” 

    physdotorg
    phys.org

    March 12, 2018
    Bob Yirka

    1
    Credit: G. W. Morley/University of Warwick and APS/Alan Stonebraker

    Two teams of researchers working independently of one another have come up with an experiment designed to prove that gravity and quantum mechanics can be reconciled. The first team is a pairing of Chiara Marletto of the University of Oxford and Vlatko Vedral of National University of Singapore. The second is an international collaboration. In the papers, both published in Physical Review Letters, the teams describe their experiment and how it might be carried out Spin Entanglement Witness for Quantum Gravity and Gravitationally Induced Entanglement between Two Massive Particles is Sufficient Evidence of Quantum Effects in Gravity.

    Gravity is a tough nut to crack, there is just no doubt about it. In comparison, the strong, weak and electromagnetic forces are a walk in the park. Scientists still can’t explain the nature of gravity, though how it works is rather well understood. The current best theory regarding gravity goes all the way back to Einstein’s general theory of relativity, but there has been no way to reconcile it with quantum mechanics. Some physicists suggest it could be a particle called the graviton. But proving that such a particle exists has been frustrating, because it would be so weak that it would be very nearly impossible to measure its force. In this new effort, neither team is suggesting that their experiment could reconcile gravity and quantum mechanics. Instead, they are claiming that if such an experiment is successful, it would very nearly prove that it should be possible to do it.

    The experiment essentially involves attempting to entangle two particles using their gravitational attraction as a means of confirming quantum gravity. In practice, it would consist of levitating two tiny diamonds a small distance from one another and putting each of them into a superposition of two spin directions. After that, a magnetic field would be applied to separate the spin components. At this point, a test would be made to see if each of the components is gravitationally attracted. If they are, the researchers contend, that will prove that gravity is quantum; if they are not, then it will not. The experiment would have to run many times to get an accurate assessment. And while a first look might suggest such an experiment could be conducted very soon, the opposite is actually true. The researchers suggest it will likely be a decade before such an experiment could be carried out due to the necessity of improving scale and the sensitivity involved in such an experiment.

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    Phys.org™ (formerly Physorg.com) is a leading web-based science, research and technology news service which covers a full range of topics. These include physics, earth science, medicine, nanotechnology, electronics, space, biology, chemistry, computer sciences, engineering, mathematics and other sciences and technologies. Launched in 2004, Phys.org’s readership has grown steadily to include 1.75 million scientists, researchers, and engineers every month. Phys.org publishes approximately 100 quality articles every day, offering some of the most comprehensive coverage of sci-tech developments world-wide. Quancast 2009 includes Phys.org in its list of the Global Top 2,000 Websites. Phys.org community members enjoy access to many personalized features such as social networking, a personal home page set-up, RSS/XML feeds, article comments and ranking, the ability to save favorite articles, a daily newsletter, and other options.

     
  • richardmitnick 8:42 am on March 9, 2018 Permalink | Reply
    Tags: , , MIT’s interdisciplinary Quantum Engineering Group (QEG), , Quantum entanglement, Scientists gain new visibility into quantum information transfer   

    From MIT: “Scientists gain new visibility into quantum information transfer” 

    MIT News

    MIT Widget

    MIT News

    March 8, 2018
    Peter Dunn | Department of Nuclear Science and Engineering

    1
    The NMR spectrometer in the Quantum Engineering Group (QEG) lab. Image: Paola Cappellaro.

    2
    Quantum many-body correlations in a spin chain grow from an initial localized state in the absence of disorder, but are restricted to a finite size by disorder, as measured by the average correlation length. Image: Paola Cappellaro.

    Advance holds promise for “wiring” of quantum computers and other systems, and opens new avenues for understanding basic workings of the quantum realm.

    When we talk about “information technology,” we generally mean the technology part, like computers, networks, and software. But information itself, and its behavior in quantum systems, is a central focus for MIT’s interdisciplinary Quantum Engineering Group (QEG) as it seeks to develop quantum computing and other applications of quantum technology.

    A QEG team has provided unprecedented visibility into the spread of information in large quantum mechanical systems, via a novel measurement methodology and metric described in a new article in Physics Review Letters. The team has been able, for the first time, to measure the spread of correlations among quantum spins in fluorapatite crystal, using an adaptation of room-temperature solid-state nuclear magnetic resonance (NMR) techniques.

    Researchers increasingly believe that a clearer understanding of information spreading is not only essential to understanding the workings of the quantum realm, where classical laws of physics often do not apply, but could also help engineer the internal “wiring” of quantum computers, sensors, and other devices.

    One key quantum phenomenon is nonclassical correlation, or entanglement, in which pairs or groups of particles interact such that their physical properties cannot be described independently, even when the particles are widely separated.

    That relationship is central to a rapidly advancing field in physics, quantum information theory. It posits a new thermodynamic perspective in which information and energy are linked — in other words, that information is physical, and that quantum-level sharing of information underlies the universal tendency toward entropy and thermal equilibrium, known in quantum systems as thermalization.

    QEG head Paola Cappellaro, the Esther and Harold E. Edgerton Associate Professor of Nuclear Science and Engineering, co-authored the new paper with physics graduate student Ken Xuan Wei and longtime collaborator Chandrasekhar Ramanathan of Dartmouth College.

    Cappellaro explains that a primary aim of the research was measuring the quantum-level struggle between two states of matter: thermalization and localization, a state in which information transfer is restricted and the tendency toward higher entropy is somehow resisted through disorder. The QEG team’s work centered on the complex problem of many-body localization (MBL) where the role of spin-spin interactions is critical.

    The ability to gather this data experimentally in a lab is a breakthrough, in part because simulation of quantum systems and localization-thermalization transitions is extremely difficult even for today’s most powerful computers. “The size of the problem becomes intractable very quickly, when you have interactions,” says Cappellaro. “You can simulate perhaps 12 spins using brute force but that’s about it — far fewer than the experimental system is capable of exploring.”

    NMR techniques can reveal the existence of correlations among spins, as correlated spins rotate faster under applied magnetic fields than isolated spins. However, traditional NMR experiments can only extract partial information about correlations. The QEG researchers combined those techniques with their knowledge of the spin dynamics in their crystal, whose geometry approximately confines the evolution to linear spin chains.

    “That approach allowed us to figure out a metric, average correlation length, for how many spins are connected to each other in a chain,” says Cappellaro. “If the correlation is growing, it tells you that interaction is winning against the disorder that’s causing localization. If the correlation length stops growing, disorder is winning and keeping the system in a more quantum localized state.”

    In addition to being able to distinguish between different types of localization (such as MBL and the simpler Anderson localization), the method also represents a possible advance toward the ability to control of these systems through the introduction of disorder, which promotes localization, Cappellaro adds. Because MBL preserves information and prevents it from becoming scrambled, it has potential for memory applications.

    The research’s focus “addresses a very fundamental question about the foundation of thermodynamics, the question of why systems thermalize and even why the notion of temperature exists at all,” says former MIT postdoc Iman Marvian, who is now an assistant professor in Duke University’s departments of Physics and Electrical and Computer Engineering. “Over the last 10 years or so there’s been mounting evidence, from analytical arguments to numerical simulations, that even though different parts of the system are interacting with each other, in the MBL phase systems don’t thermalize. And it is very exciting that we can now observe this in an actual experiment.”

    “People have proposed different ways to detect this phase of matter, but they’re difficult to measure in a lab,” Marvian explains. “Paola’s group studied it from a new point of view and introduced quantities that can be measured. I’m really impressed at how they’ve been able to extract useful information about MBL from these NMR experiments. It’s great progress, because it makes it possible to experiment with MBL on a natural crystal.”

    The research was able to leverage NMR-related capabilities developed under a previous grant from the US Air Force, says Cappellaro, and some additional funding from the National Science Foundation. Prospects for this research area are promising, she adds. “For a long time, most many-body quantum research was focused on equilibrium properties. Now, because we can do many more experiments and would like to engineer quantum systems, there’s much more interest in dynamics, and new programs devoted to this general area. So hopefully we can get more funding and continue the work.”

    See the full article here .

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  • richardmitnick 12:02 pm on February 15, 2018 Permalink | Reply
    Tags: , , , , Quantum entanglement, , U Vienna   

    From U Vienna: “Fingerprints of quantum entanglement” 

    University of Vienna

    15. February 2018

    Dr. Borivoje Dakic
    Fakultät für Physik
    Universität Wien & IQOQI Wien, ÖAW
    1090 – Wien, Boltzmanngasse 5
    + 43-4277-725 80
    borivoje.dakic@univie.ac.at

    Rückfragehinweis
    Mag. Alexandra Frey
    Pressebüro der Universität Wien
    Forschung und Lehre
    Universität Wien
    1010 – Wien, Universitätsring 1
    +43-1-4277-175 33
    +43-664-60277-175 33
    alexandra.frey@univie.ac.at

    Dipl.-Soz. Sven Hartwig
    Leitung Öffentlichkeit & Kommunikation
    Österreichische Akademie der Wissenschaften
    1010 – Wien, Dr. Ignaz Seipel-Platz 2
    +43 1 51581-13 31
    sven.hartwig@oeaw.ac.at

    1
    Entangled qubits are sent to measurement devices which output a sequence of zeroes and ones. This pattern heavily depends on the type of measurements performed on individual qubits. If we pick the set of measurements in a peculiar way, entanglement will leave unique fingerprints in the measurement patterns (Copyright: Juan Palomino).

    Quantum entanglement is a key feature of a quantum computer. Yet, how can we verify that a quantum computer indeed incorporates a large-scale entanglement? Using conventional methods is hard since they require a large number of repeated measurements. Aleksandra Dimić from the University of Belgrade and Borivoje Dakić from the Austrian Academy of Sciences and the University of Vienna have developed a novel method where in many cases even a single experimental run suffices to prove the presence of entanglement. Their surprising results will be published in the online open access journal npj Quantum Information of the Nature Publishing group.

    The ultimate goal of quantum information science is to develop a quantum computer, a fully-fledged controllable device which makes use of the quantum states of subatomic particles to store information. As with all quantum technologies, quantum computing is based on a peculiar feature of quantum mechanics, quantum entanglement. The basic units of quantum information, the qubits, need to correlate in this particular way in order for the quantum computer to achieve its full potential.

    One of the main challenges is to make sure that a fully functional quantum computer is working as anticipated. In particular, scientists need to show that the large number of qubits are reliably entangled. Conventional methods require a large number of repeated measurements on the qubits for reliable verification. The more often a measurement run is repeated the more certain one can be about the presence of entanglement. Therefore, if one wants to benchmark entanglement in large quantum systems it will require a lot of resources and time, which is practically difficult or simply impossible. The main question arises: can we prove entanglement with only a low number of measurement trials?

    Now researchers from the University of Belgrade, the University of Vienna and the Austrian Academy of Sciences have developed a novel verification method which requires significantly fewer resources and, in many cases, even only a single measurement run to prove large-scale entanglement with a high confidence. For Aleksandra Dimić from the University of Belgrade, the best way to understand this phenomenon is to use the following analogy: “Let us consider a machine which simultaneously tosses, say, ten coins. We manufactured the machine such that it should produce correlated coins. We now want to validate whether the machine produces the anticipated result. Imagine a single trial revealing all coins landing on tails. This is a clear signature of correlations, as ten independent coins have 0.01% chance to land on the same side simultaneously. From such an event, we certify the presence of correlations with more than 99.9% confidence. This situation is very similar to quantum correlations captured by entanglement.” Borivoje Dakić says: “In contrast to classical coins, qubits can be measured in many, many different ways. The measurement result is still a sequence of zeros and ones, but its structure heavily depends on how we choose to measure individual qubits”, he continues. “We realized that, if we pick these measurements in a peculiar way, entanglement will leave unique fingerprints in the measured pattern”, he concludes.

    The developed method promises a dramatic reduction in time and resources needed for reliable benchmark of future quantum devices.

    Publication in npj Quantum Information:
    A.Dimić and B.Dakić, “Single-copy enntaglement detection”, npj Quantum Information, 2018.
    DOI: 10.1038/s41534-017-0055-x
    http://www.nature.com/articles/s41534-017-0055-x

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    The University of Vienna (German: Universität Wien) is a public university located in Vienna, Austria. It was founded by Duke Rudolph IV in 1365 and is one of the oldest universities in the German-speaking world. With its long and rich history, the University of Vienna has developed into one of the largest universities in Europe, and also one of the most renowned, especially in the Humanities. It is associated with 15 Nobel prize winners and has been the academic home to a large number of scholars of historical as well as of academic importance.

     
  • richardmitnick 5:33 pm on November 7, 2017 Permalink | Reply
    Tags: A way to link a group of atoms’ quantum mechanical properties among themselves far more quickly than is currently possible potentially providing a tool for highly precise sensing and quantum compute, , Dipolar interaction, Getting the atoms into an entangled state more quickly would be a potential advantage in any practical application not least because entanglement can be fleeting, Need Entangled Atoms? Get 'Em FAST! With NIST’s New Patent-Pending Method, , , Quantum entanglement, Uncertainty is the key here   

    From NIST: “Need Entangled Atoms? Get ‘Em FAST! With NIST’s New Patent-Pending Method” 


    NIST

    November 07, 2017

    Chad Boutin
    boutin@nist.gov
    (301) 975-4261

    1
    While quantum entanglement usually spreads through the atoms in an optical lattice via short-range interactions with the atoms’ immediate neighbors (left), new theoretical research shows that taking advantage of long-range dipolar interactions among the atoms could enable it to spread more quickly (right), a potential advantage for quantum computing and sensing applications.
    Credit: Gorshkov and Hanacek/NIST

    Physicists at the National Institute of Standards and Technology (NIST) have come up with a way to link a group of atoms’ quantum mechanical properties among themselves far more quickly than is currently possible, potentially providing a tool for highly precise sensing and quantum computer applications. NIST has applied for a patent on the method, which is detailed in a new paper in Physical Review Letters.

    The method, which has not yet been demonstrated experimentally, essentially would speed up the process of quantum entanglement in which the properties of multiple particles become interconnected with one other. Entanglement would propagate through a group of atoms in dramatically less time, allowing scientists to build an entangled system exponentially faster than is common today.

    Arrays of entangled atoms suspended in laser light beams, known as optical lattices, are one approach to creating the logic centers of prototype quantum computers, but an entangled state is difficult to maintain more than briefly. Applying the method to these arrays could give scientists precious time to do more with these arrays of atoms before entanglement is lost in a process known as decoherence.

    The method takes advantage of a physical relationship among the atoms called dipolar interaction, which allows atoms to influence each other over greater distances than previously possible. The research team’s Alexey Gorshkov compares it to sharing tennis balls among a group of people. While previous methods essentially allowed people to pass tennis balls only to a person standing next to them, the new approach would allow an individual to toss them to people across the room.

    “It is these long-range dipolar interactions in 3-D that enable you to create entanglement much faster than in systems with short-range interactions,” said Gorshkov, a theoretical physicist at NIST and at both the Joint Center for Quantum Information and Computer Science and the Joint Quantum Institute, which are collaborations between NIST and the University of Maryland. “Obviously, if you can throw stuff directly at people who are far away, you can spread the objects faster.”

    Applying the technique would center around adjusting the timing of laser light pulses, turning the lasers on and off in particular patterns and rhythms to quick-change the suspended atoms into a coherent entangled system.

    The approach also could find application in sensors, which might exploit entanglement to achieve far greater sensitivity than classical systems can. While entanglement-enhanced quantum sensing is a young field, it might allow for high-resolution scanning of tiny objects, such as distinguishing slight temperature differences among parts of an individual living cell or performing magnetic imaging of its interior.

    Gorshkov said the method builds on two studies from the 1990s in which different NIST researchers considered the possibility of using a large number of tiny objects—such as a group of atom—as sensors. Atoms could measure the properties of a nearby magnetic field, for example, because the field would change their electrons’ energy levels. These earlier efforts showed that the uncertainty in these measurements would be advantageously lower if the atoms were all entangled, rather than merely a bunch of independent objects that happened to be near one another.

    “Uncertainty is the key here,” said Gorshkov. “You want that uncertainty as low as possible. If the atoms are entangled, you have less uncertainty about that magnetic field’s magnitude.”

    Getting the atoms into an entangled state more quickly would be a potential advantage in any practical application, not least because entanglement can be fleeting.

    When a group of atoms is entangled, the quantum state of each one is bound up with the others so that the entire system possesses a single quantum state. This connection can exist even if the atoms are separated and completely isolated from one another (giving rise to Einstein’s famous description of it as “spooky action at a distance”), but entanglement is also quite a fragile condition. The difficulty of maintaining it among large numbers of atoms has slowed the development of entanglement-based technologies such as quantum computers.

    “Entangled states tend to decohere and go back to being a bunch of ordinary independent atoms,” Gorshkov said. “People knew how to create entanglement, but we looked for a way to do it faster.”

    If the method can be experimentally demonstrated, it could give a quantum computer’s processor additional time so it can outpace decoherence, which threatens to make a computation fall apart before the qubits can finish their work. It would also reduce the uncertainty if used in sensing applications.

    “We think this is a practical way to increase the speed of entanglement,” Gorshkov said. “It was cool enough to patent, so we hope it proves commercially useful to someone.”

    See the full article here.

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    NIST Mission, Vision, Core Competencies, and Core Values

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    NIST will be the world’s leader in creating critical measurement solutions and promoting equitable standards. Our efforts stimulate innovation, foster industrial competitiveness, and improve the quality of life.
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    Perseverance: We take the long view, planning the future with scientific knowledge and imagination to ensure continued impact and relevance for our stakeholders.
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  • richardmitnick 7:29 am on October 9, 2017 Permalink | Reply
    Tags: Back in 1905 Einstein had helped pioneer quantum theory with his revolutionary discovery that light has the characteristics of both a wave and a particle, Bohr found a flaw in Einstein’s logic, But does this also mean “spooky action at a distance” is real?, , Einstein and Bohr continued to debate the issue for the rest of their lives, , Einstein was the first to publicly support de Broglie’s bold hypothesis, Einstein-Podolsky-Rosen paradox, Einstein: “God does not play dice with the universe”, Einstein’s hopes of finding hidden variables that would take the uncertainty out of quantum theory were dashed, Erwin Schrödinger, Fifth Solvay Congress in Brussels, Instant action violated Einstein’s theory of relativity: nothing can travel faster than the speed of light, Louis de Broglie, , Quantum entanglement, , The Copenhagen theory held that subatomic particles were ruled by chance   

    From COSMOS: “Einstein, Bohr and the origins of entanglement” Wonderful article on this debate between Einstein and Bohr 

    Cosmos Magazine bloc

    COSMOS Magazine

    06 October 2017
    Robyn Arianrhod

    Two of history’s greatest physicists argued for decades over one of the deepest mysteries of quantum mechanics. Today, their successors are opening new fronts in the battle to understand ‘spooky action at a distance’.

    1
    Niels Bohr and Albert Einstein at the Fifth Solvay Congress. American Institute Of Physics / Getty Images

    It all began in October 1927, at the Fifth Solvay Congress in Brussels. It was Louis de Broglie’s first congress, and he had been “full of pleasure and curiosity” at the prospect of meeting Einstein, his teenage idol. Now 35, de Broglie happily reported: “I was particularly struck by his mild and thoughtful expression, by his general kindness, by his simplicity, and by his friendliness.”

    Back in 1905, Einstein had helped pioneer quantum theory with his revolutionary discovery that light has the characteristics of both a wave and a particle. Niels Bohr later explained this as “complementarity”: depending on how you observe light, you will see either wave or particle behaviour. As for de Broglie, he had taken Einstein’s idea into even stranger territory in his 1924 PhD thesis: if light waves could behave like particles, then perhaps particles of matter could also behave like waves! After all, Einstein had shown that energy and matter were interchangeable, via E = mc2.

    Einstein was the first to publicly support de Broglie’s bold hypothesis. By 1926, Erwin Schrödinger had developed a mathematical formula to describe such “matter waves”, which he pictured as some kind of rippling sea of smeared-out particles. But Max Born showed that Schrödinger’s waves are, in effect, “waves of probability”. They encode the statistical likelihood that a particle will show up at a given place and time based on the behaviour of many such particles in repeated experiments. When the particle is observed, something strange appears to happen. The wave-function “collapses” to a single point, allowing us to see the particle at a particular position.

    Born’s probability wave also fitted neatly with Werner Heisenberg’s recently proposed “uncertainty principle”. Heisenberg had concluded that in the quantum world it is not possible to obtain exact information about both the position and the momentum of a particle at the same time. He imagined the very act of measuring a quantum particle’s position, say by shining a light on it, gave it a jolt that changed its momentum, so the two could never be precisely measured at once.

    When the world’s leading physicists gathered in Brussels in 1927, this was the strange state of quantum physics.

    The official photograph of the participants shows 28 besuited, sober-looking men, and one equally serious woman, Marie Curie. But fellow physicist Paul Ehrenfest’s private photo of intellectual adversaries Bohr and Einstein captures the spirit of the conference: Bohr looks intensely thoughtful, hand on his chin, while Einstein is leaning back looking relaxed and dreamy. This gentle, contemplative picture belies the depth of the famous clash between these two intellectual titans – a clash that hinged on the extraordinary concept of quantum entanglement.

    At the congress, Bohr presented his view of quantum mechanics for the first time. Dubbed the Copenhagen interpretation, in honour of Bohr’s home city, it combined his own idea of particle-wave complementarity with Born’s probability waves and Heisenberg’s uncertainty principle.

    Most of the attendees readily accepted this view, but Einstein was perturbed. It was one thing for groups of particles to be ruled by chance; indeed Einstein had explained the jittery motion of pollen in apparently still water (dubbed Brownian motion) by invoking the random group behaviour of water molecules. Individual molecules, though, would still be ruled by Newton’s laws of motion; their exact movements could in principle be calculated.

    By contrast, the Copenhagen theory held that subatomic particles were ruled by chance.

    Einstein began his attack in the time-honoured tradition of reductio ad absurdum – arguing that the logical extension of quantum theory would lead to an absurd outcome.

    After several sleepless nights, Bohr found a flaw in Einstein’s logic. Einstein did not retreat: he was sure he could convince Bohr of the absurdity of this strange new theory. Their debate flowed over into the Sixth Solvay Congress in 1930, and on until Einstein felt he finally had the pieces in place to checkmate Bohr at the seventh congress in 1933. Two weeks before that, however, Nazi persecution forced Einstein to flee to the United States. The planned checkmate would have to wait.

    When it came, it was deceptively simple. In 1935 at Princeton, Einstein and two collaborators, Boris Podolsky and Nathan Rosen, published what became known as the Einstein-Podolsky-Rosen paradox [Physical Review Journals Archive], or EPR for short. Podolsky wrote up the thought experiment in a mathematical form, but let me illustrate it with jellybeans.

    Suppose you have a red and a green jellybean in a box. The box seals off the jellybeans from all others: technically speaking, the pair form an “isolated system”, and they are “entangled” in the sense that the colour of one jellybean gives information about the other. You can see this by asking a friend to close her eyes and pick a jellybean at random. If she picks red, you know the remaining sweet is green.

    This is key to EPR: by knowing the colour of your friend’s jellybean, you can know the colour of your own without “disturbing” it by looking at it. But in trying to bypass the supposed observer-effect in this way, EPR had also inadvertently uncovered the strange idea of “entanglement”. The term was coined by Schrödinger after he read the EPR paper .

    So now apply this technique to two electrons. Instead of a colour, each one has an intrinsic property called “spin”. Imagine something like the spin axis of a gyroscope. If two electrons are prepared together in the lab so that they have zero total spin, then the principle of conservation of angular momentum means that if one of the electrons has its spin axis up, the other electron’s axis must be down. The electrons are entangled, just as the jellybeans were.

    2

    With jellybeans, the colour of your friend’s chosen sweet is fixed, whether or not she actually observes it. With electrons, by contrast, until your friend makes her observation, quantum theory simply says there is a 50% chance its spin is up, and 50% it is down.

    The EPR attempt to strike at the heart of quantum theory now goes like this. Perhaps the spin of your friend’s electron was in fact determined before she picked it out. However, like a watermark that can’t be detected until a special light is shone on it, the spin state is only revealed when she looks at it. Quantum spin, then, involves a “hidden variable”, yet to be described by quantum theory. Alternatively, if quantum mechanics is correct and complete, then the theory defies common sense – because as soon as your friend checks the spin of her electron, your electron appears to respond instantly, because if hers is “up” then yours will be “down”.

    This is because the correlation between the two spins was built into the experiment when the electrons were first entangled, just as putting the two jellybeans in a box ensures the colour of your jellybean will be “opposite” that of your friend’s. The implications are profound. Even if your friend moved to the other side of the galaxy, your electron would “know” that it must manifest the opposite spin in the instant she makes her observation.

    Of course, instant action violated Einstein’s theory of relativity: nothing can travel faster than the speed of light. Hence Einstein dubbed this absurd proposition “spooky action at a distance”.

    But there was more. Spin is not the only property your friend could have chosen to observe. What EPR showed, then, is that the physical nature of your electron seems to have no identity of its own. Rather, it depends on how your friend chooses to observe her electron. As Einstein put it: “Do you really believe the Moon is there only when you look at it?” The EPR paper concluded: “No reasonable definition of reality could be expected to permit this.” Ergo, the authors believed, quantum theory had some serious problems.

    Bohr was stumped by EPR. He ditched the idea that the act of measurement jolted the state of the particle. (Indeed, later experiments would show that uncertainty is not solely the result of an interfering observer; it is an inherent characteristic of particles.)

    But he did not abandon the uncertainty at the heart of quantum mechanics. Instead of trying to wrestle with the real world implications, he concluded [Physical Review Journals Archive] that we can only speak of what we observe – at the beginning of the experiment and the end when your friend’s electron is definitely “up”, say. We cannot speak about what happens in between.

    Einstein and Bohr continued to debate the issue for the rest of their lives. What they really disagreed about was the nature of reality. Bohr believed that nature was fundamentally random. Einstein did not. “God does not play dice with the universe,” he declared.

    Nevertheless, Einstein knew that quantum theory accurately described the results of real as opposed to thought experiments. So most physicists considered that Bohr had won. They focused on applying quantum theory, and questions about the EPR paradox and entanglement became a niche interest.

    In 1950, Chien-Shiung Wu and Irving Shaknov [Physical Review Journals Archive] found oddly linked behaviour in pairs of photons. They didn’t know it at the time but it was the first real-world observation of quantum entanglement.

    ___________________________________________________________________________
    Some suggest that something like a ‘wormhole’ – a tunnel in spacetime between two widely separated black holes, a consequence of general relativity theory first deduced by Einstein and Rosen – may be the mechanism underlying entanglement.
    ___________________________________________________________________________

    Later, David Bohm realised [Physical Review Journals Archive] Wu and Shaknov’s discovery was an opportunity to take entanglement out of the realm of thought experiments and into the lab. Following Bohm, in 1964 John Bell translated the two EPR alternatives into a mathematical relationship that could be tested. But it was left to other experimenters – most famously Alain Aspect in 1981 [Physical Review Letters] – to carry out the tests.

    Einstein’s hopes of finding hidden variables that would take the uncertainty out of quantum theory were dashed. There seemed no escaping the bizarre consequences of EPR and the reality of entanglement.

    But does this also mean “spooky action at a distance” is real? Entanglement in electrons has been demonstrated at distances of a kilometre or two. But so far that’s too short a distance to know if faster-than-light interactions between them were involved. Things may soon become clearer: at the time of writing, Chinese scientists have just announced the successful transmission of entangled photons [Science] from an orbiting satellite over distances of more than 1,200 km.

    On the other hand, some physicists have recently taken up Einstein’s side of the argument. For instance, in 2016 Bengt Nordén, of Chalmers University in Sweden, published a paper [Cambridge Quarterly Reviews of Biophysics] entitled, Quantum entanglement: facts and fiction – how wrong was Einstein after all? Against Bohr’s better judgement, such physicists are once again asking about the meaning of reality, and wondering what is causing the weird phenomenon of entanglement.

    Some even suggest that something like a “wormhole” – a tunnel in spacetime between two widely separated black holes, a consequence of general relativity theory first deduced by Einstein and Rosen – may be the mechanism underlying entanglement. The mythical faster-than-light tachyon is another possible contender.

    But nearly everyone agrees that whatever is going on between entangled particles, experimenters can only communicate their observations of entangled particles at light speed or less.

    Entanglement is no longer a philosophical curio: not only are physicists using it to encrypt information and relying on it to underpin the design of tomorrow’s quantum computers, they are once again grappling with the hard questions about the nature of reality that entanglement raises.

    Ninety years after the Fifth Solvay Congress, Einstein’s thought experiments continue to drive science onwards.

    See the full article here .

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  • richardmitnick 8:27 am on September 14, 2017 Permalink | Reply
    Tags: , Brian Greene, Cosmology- origins of the universe, , , , Quantum entanglement, , Superstring theory, Unified theory of physics,   

    From Harvard Gazette: “A master of explaining the universe” 

    Harvard University
    Harvard University

    September 13, 2017
    Colleen Walsh

    1
    Brian Greene ’84, a Columbia University theoretical physicist and mathematician, has made it his mission to illuminate the wonders of the universe for non-scientists. Photo by Greg Kessler/World Science Festival

    Harvard Overseer and Columbia physicist Brian Greene seeks wider audience for the wonders of science.

    He is the founder of the World Science Festival, the author of numerous best-selling books, including the Pulitzer Prize finalist “The Elegant Universe,” and an expert at explaining knotty concepts. Now he’s back at Harvard. On Sept. 19, Brian Greene ’84, Harvard Overseer and Columbia University theoretical physicist and mathematician, will explore shifting ideas of space, time, and reality in a talk at the Radcliffe Institute for Advanced Study. The Gazette caught up with Greene to ask him about his years at Harvard, his passion for science, and how he defines superstring theory in a tweet.

    GAZETTE: Where did your initial interest in math and physics come from?

    GREENE: When I was a kid growing up in Manhattan I was deeply fascinated with mathematics, and at a young age my dad taught me the basics of arithmetic. I was captivated from then on by the ability to use a few simple rules to undertake calculations that no one had ever done before. Now, most of these calculations weren’t ever done because they weren’t interesting, but for a kid to be able to do something new is deeply thrilling. Later on, when I learned in high school and most forcefully when I got to college at Harvard that math isn’t merely a game but it’s something that can help you understand what happens out there in the real universe, then I was kind of hooked for life.

    GAZETTE: Were there any classes or professors that had a big impact on you at Harvard?

    GREENE: Oh, huge. Howard Georgi was my freshman physics professor, and he had a deep impact on my love of the subject. There’s now a mathematician who wasn’t at Harvard when I was an undergrad but whom I worked with extensively as a graduate student and then he moved to Harvard, Shing-Tung Yau in the Mathematics Department. He had a deep impact on me. The Harvard faculty had quite a formative impact on me across the years.

    GAZETTE: I know you are famous for being able to explain awesome scientific concepts. In the age of social media, can you define superstring theory in a tweet?

    GREENE: Superstring theory is our best attempt to realize Einstein’s dream of the unified theory. #unification.

    GAZETTE: So break that down for me, and this doesn’t have to be in a tweet format. What is the unified theory of physics and why is it so important?

    GREENE: Einstein envisioned that there might be a master law of physics, perhaps captured by a single mathematical equation that would be so powerful that in principle it could describe every physical process in the universe — the big stuff, the small stuff, and everything in between. And he believed it so deeply that he pursued it relentlessly for the last 30 years of his life. On various occasions Einstein announced that he had the unified theory, always, however, to have to retract that sometime later when he realized that his latest proposal didn’t quite work. In the end it was a very frustrating experience for him. And when he died, that dream of unification died with him. But about 10 or 15 years later some scientist stumbled upon a new approach — this approach called superstring theory — and over the course of decades realized that this may in fact be the unified theory that Einstein was looking for. And that’s what we have been developing ever since.

    GAZETTE: What has been the main focus of your work for the last several years?

    GREENE: I have been working on issues of cosmology, origins of the universe. I’ve been working on the possibility of a multiverse — that we might live in a reality that comprises more than one universe. I’ve been working on some strange features of quantum mechanics called quantum entanglement, where distant objects can somehow act as though they are sitting right next to each other. Again this is a discovery that sort of goes back to Einstein himself, so things in that domain have been my main focus of late.

    GAZETTE: Tell me more about multiple universes.

    GREENE: Well, it’s a curious idea because for most people the word universe means everything: all that there is. But developments over the past couple of decades have convinced many of us that there is at least a possibility that what we have long thought to be everything is actually perhaps just a small part of a much bigger reality. And that bigger reality might have other realms that would rightly be called universes of their own, and if that’s the case then the grand picture of reality involves a whole collection of universes, and that’s why we no longer use the word universe to describe all there is … we speak of “multi” — there are multiverses because of this multiplicity of universes.

    GAZETTE: Is there current or future research that you could see really changing the nature of how we see the universe?

    GREENE: My own feeling, and it’s shared by colleagues, is that the next breakthrough will come when we deeply understand the fundamental ingredients of space and time themselves. And this is an open question. Just like matter is made up of atoms and molecules, could it be that space and time are themselves made up of more fundamental constituents? In fact, this is what I will be talking about at Radcliffe, recent work that at least hints at an answer to what the ingredients of space and time might actually be.

    GAZETTE: What has inspired you to work to make science understandable?

    GREENE: My view of science is not that it’s merely an effort to unearth the basic laws of physics, but I view it more as a very human undertaking to see how we fit into the grand scheme of things and to answer the questions that have been asked since the time we could ask questions: Where did we come from? What are we made of? How did the universe come to be? What is time? What will happen in the distant future? All these questions I think speak deeply to who we are as a species, and for the vast majority of people to be cut off from the most up-to-date thinking on these deep questions because they don’t speak mathematics, they don’t have a graduate degree in physics, I think that’s tragic. So for decades now I’ve felt that part of my charge is to bring these ideas to a wider audience, to make them available to anyone who has a curiosity and a little bit of stick-to-itiveness to push through some deep, difficult, but ultimately gratifying ideas.

    GAZETTE: If you weren’t a physicist what would you be?

    GREENE: Well, if I was starting out today I think I would probably go into neuroscience. I like to think of the big questions. Where did the universe come from? Where did life come from? And where does mind come from? And for those I think the time is really ripe to understand the nature of intelligence and thought. I think there are going to be great, great breakthroughs in that area in the next couple of decades.

    GAZETTE: Favorite physicist?

    GREENE: There’s nobody who compares with Isaac Newton in terms of the leap that he pushed humanity through from the way we understood the world before he began to think about it until after he existed.

    GAZETTE: What is your take on Voyager?

    GREENE: The “Star Trek” version or the real version?

    GAZETTE: The real version.

    GREENE: I think it’s a great symbol of who we are as a species. We are explorers. We are deeply committed to understanding the universe, and to envision these little spacecraft that have left the solar system and they are floating out there in the great unknown as harbingers, if you will, of human life back on the planet is a deeply moving picture and one that really captures who we are.

    See the full article here .

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    Harvard University campus
    Harvard is the oldest institution of higher education in the United States, established in 1636 by vote of the Great and General Court of the Massachusetts Bay Colony. It was named after the College’s first benefactor, the young minister John Harvard of Charlestown, who upon his death in 1638 left his library and half his estate to the institution. A statue of John Harvard stands today in front of University Hall in Harvard Yard, and is perhaps the University’s best known landmark.

    Harvard University has 12 degree-granting Schools in addition to the Radcliffe Institute for Advanced Study. The University has grown from nine students with a single master to an enrollment of more than 20,000 degree candidates including undergraduate, graduate, and professional students. There are more than 360,000 living alumni in the U.S. and over 190 other countries.

     
  • richardmitnick 9:21 am on August 28, 2017 Permalink | Reply
    Tags: , Chinese Physicists Just Achieved Quantum Teleportation Underwater For The First Time, Quantum entanglement,   

    From Science Alert: “Physicists Just Achieved Quantum Teleportation Underwater For The First Time” 

    ScienceAlert

    Science Alert

    28 AUG 2017
    FIONA MACDONALD

    1
    sakkmesterke/Shutterstock.com

    Chinese scientists have successfully sent information between entangled particles through sea water, the first time this type of quantum communication has been achieved underwater.

    In this proof-of-concept experiment, information was sent across a 3.3-metre (10.8-foot) long tank of seawater, but the researchers predict they should be able to use the same technique to send unhackable communications close to 900 metres (0.55 miles) through open water.

    “People have talked about the idea of underwater quantum communication before, but I’m not aware of anyone who has done an experiment like this,” Thomas Jennewein from the University of Waterloo in Canada told Devin Powell over at New Scientist.

    “An obvious application would be a submarine which wants to remain submerged but communicate in a secure fashion.”

    This is a big deal, because quantum communication – also known as quantum teleportation – promises to allow people to send messages that are protected from prying eyes by the laws of physics. It’s the ultimate encryption.

    It’s based on the idea of quantum entanglement – that kooky phenomenon Einstein referred to as “spooky at a distance”. Basically, quantum entanglement means that two particles become inextricably linked so that whatever happens to one will automatically affect the other, no matter how far apart they are.

    Through that mechanism, scientists have already ‘teleported’ information across vast distances through optical fibre and even open space.

    Earlier this year, a separate team of Chinese researchers were able to use quantum entanglement to teleport information to a satellite in Earth’s orbit across more than 500 km (311 miles).

    But up until now, no one had done the same thing in water, which is notorious for scattering anything we try to beam through it. Just think of shining a laser pointer into the air and into water.

    For this experiment, researchers from Shanghai Jiao Tong University took seawater from the Yellow Sea and set it up in a 3 metre tank in the lab.

    They then created a pair of entangled photons by shooting a beam of light through a crystal. Whatever the polarisation of one of the photons, its pair would automatically have the opposite polarisation.

    These particles were placed at opposite ends of the tank, and the team showed that despite being separated by metres of seawater, they could accurately communicate information between them more than 98 percent of the time.

    “Our results confirm the feasibility of a seawater quantum channel, representing the first step towards underwater quantum communication,” the researchers write in the journal The Optical Society.

    It’s still early days, and not only is it important for other teams to now replicate this result, but it remains to be seen whether the same thing can be done across greater distances, but also in seawater not confined to a tank.

    Based on the team’s calculations, they predict that it would be possible to achieve quantum communication through open water across a distance of 885 metres (0.55 miles) using photons in the blue-green window.

    But New Scientist reports that other groups have calculated a limit of underwater quantum communication of just 120 metres (0.07 miles).

    “Because ocean water absorbs light, extending this is going to difficult,” Jeffrey Uhlmann, a physicists from the University of Missouri in Columbia, told Powell.

    How far we can stretch this underwater quantum communication remains to be seen, but now that researchers have shown it’s possible, it’s only a matter of time before the limits begin to be pushed.

    See the full article here .

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  • richardmitnick 10:27 am on July 12, 2017 Permalink | Reply
    Tags: , , , , Micius satellite, , Quantum entanglement, Teleportation achieved   

    From MIT Tech Review: “First Object Teleported from Earth to Orbit” 

    MIT Technology Review
    M.I.T Technology Review

    July 10, 2017
    No writer credit found

    Researchers in China have teleported a photon from the ground to a satellite orbiting more than 500 kilometers above.

    Last year, a Long March 2D rocket took off from the Jiuquan Satellite Launch Centre in the Gobi Desert carrying a satellite called Micius, named after an ancient Chinese philosopher who died in 391 B.C. The rocket placed Micius in a Sun-synchronous orbit so that it passes over the same point on Earth at the same time each day.

    Micius is a highly sensitive photon receiver that can detect the quantum states of single photons fired from the ground. That’s important because it should allow scientists to test the technological building blocks for various quantum feats such as entanglement, cryptography, and teleportation.

    2
    Micius satellite. https://www.fusecrunch.com/chinas-first-quantum-satellite.html

    Today, the Micius team announced the results of its first experiments. The team created the first satellite-to-ground quantum network, in the process smashing the record for the longest distance over which entanglement has been measured. And they’ve used this quantum network to teleport the first object from the ground to orbit.

    Teleportation has become a standard operation in quantum optics labs around the world. The technique relies on the strange phenomenon of entanglement. This occurs when two quantum objects, such as photons, form at the same instant and point in space and so share the same existence. In technical terms, they are described by the same wave function.

    3
    No image caption or credit.

    The curious thing about entanglement is that this shared existence continues even when the photons are separated by vast distances. So a measurement on one immediately influences the state of the other, regardless of the distance between them.

    Back in the 1990s, scientists realized they could use this link to transmit quantum information from one point in the universe to another. The idea is to “download” all the information associated with one photon in one place and transmit it over an entangled link to another photon in another place.

    This second photon then takes on the identity of the first. To all intents and purposes, it becomes the first photon. That’s the nature of teleportation and it has been performed many times in labs on Earth.

    Teleportation is a building block for a wide range of technologies. “Long-distance teleportation has been recognized as a fundamental element in protocols such as large-scale quantum networks and distributed quantum computation,” says the Chinese team.

    In theory, there should be no maximum distance over which this can be done. But entanglement is a fragile thing because photons interact with matter in the atmosphere or inside optical fibers, causing the entanglement to be lost.

    As a result, the distance over which scientists have measured entanglement or performed teleportation is severely limited. “Previous teleportation experiments between distant locations were limited to a distance on the order of 100 kilometers, due to photon loss in optical fibers or terrestrial free-space channels,” says the team.

    But Micius changes all that because it orbits at an altitude of 500 kilometers, and for most of this distance, any photons making the journey travel through a vacuum. To minimize the amount of atmosphere in the way, the Chinese team set up its ground station in Ngari in Tibet at an altitude of over 4,000 meters. So the distance from the ground to the satellite varies from 1,400 kilometers when it is near the horizon to 500 kilometers when it is overhead.

    To perform the experiment, the Chinese team created entangled pairs of photons on the ground at a rate of about 4,000 per second. They then beamed one of these photons to the satellite, which passed overhead every day at midnight. They kept the other photon on the ground.

    Finally, they measured the photons on the ground and in orbit to confirm that entanglement was taking place, and that they were able to teleport photons in this way. Over 32 days, they sent millions of photons and found positive results in 911 cases. “We report the first quantum teleportation of independent single-photon qubits from a ground observatory to a low Earth orbit satellite—through an up-link channel— with a distance up to 1400 km,” says the Chinese team.

    This is the first time that any object has been teleported from Earth to orbit, and it smashes the record for the longest distance for entanglement.

    That’s impressive work that sets the stage for much more ambitious goals in the future. “This work establishes the first ground-to-satellite up-link for faithful and ultra-long-distance quantum teleportation, an essential step toward global-scale quantum internet,” says the team.

    It also shows China’s obvious dominance and lead in a field that, until recently, was led by Europe and the U.S.—Micius would surely have been impressed. But an important question now is how the West will respond.

    See the full article here .

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    The mission of MIT Technology Review is to equip its audiences with the intelligence to understand a world shaped by technology.

     
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