Tagged: Yale Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 4:58 pm on November 14, 2017 Permalink | Reply
    Tags: , , , , , Quantum Circuits Company, , , , Robert Schoelkopf is at the forefront of a worldwide effort to build the world’s first quantum computer, Yale   

    From NYT: “Yale Professors Race Google and IBM to the First Quantum Computer” 

    New York Times

    The New York Times

    NOV. 13, 2017
    CADE METZ

    1
    Prof. Robert Schoelkopf inside a lab at Yale University. Quantum Circuits, the start-up he has created with two of his fellow professors, is located just down the road. Credit Roger Kisby for The New York Times

    Robert Schoelkopf is at the forefront of a worldwide effort to build the world’s first quantum computer. Such a machine, if it can be built, would use the seemingly magical principles of quantum mechanics to solve problems today’s computers never could.

    Three giants of the tech world — Google, IBM, and Intel — are using a method pioneered by Mr. Schoelkopf, a Yale University professor, and a handful of other physicists as they race to build a machine that could significantly accelerate everything from drug discovery to artificial intelligence. So does a Silicon Valley start-up called Rigetti Computing. And though it has remained under the radar until now, those four quantum projects have another notable competitor: Robert Schoelkopf.

    After their research helped fuel the work of so many others, Mr. Schoelkopf and two other Yale professors have started their own quantum computing company, Quantum Circuits.

    Based just down the road from Yale in New Haven, Conn., and backed by $18 million in funding from the venture capital firm Sequoia Capital and others, the start-up is another sign that quantum computing — for decades a distant dream of the world’s computer scientists — is edging closer to reality.

    “In the last few years, it has become apparent to us and others around the world that we know enough about this that we can build a working system,” Mr. Schoelkopf said. “This is a technology that we can begin to commercialize.”

    Quantum computing systems are difficult to understand because they do not behave like the everyday world we live in. But this counterintuitive behavior is what allows them to perform calculations at rate that would not be possible on a typical computer.

    Today’s computers store information as “bits,” with each transistor holding either a 1 or a 0. But thanks to something called the superposition principle — behavior exhibited by subatomic particles like electrons and photons, the fundamental particles of light — a quantum bit, or “qubit,” can store a 1 and a 0 at the same time. This means two qubits can hold four values at once. As you expand the number of qubits, the machine becomes exponentially more powerful.

    Todd Holmdahl, who oversees the quantum project at Microsoft, said he envisioned a quantum computer as something that could instantly find its way through a maze. “A typical computer will try one path and get blocked and then try another and another and another,” he said. “A quantum computer can try all paths at the same time.”

    The trouble is that storing information in a quantum system for more than a short amount of time is very difficult, and this short “coherence time” leads to errors in calculations. But over the past two decades, Mr. Schoelkopf and other physicists have worked to solve this problem using what are called superconducting circuits. They have built qubits from materials that exhibit quantum properties when cooled to extremely low temperatures.

    With this technique, they have shown that, every three years or so, they can improve coherence times by a factor of 10. This is known as Schoelkopf’s Law, a playful ode to Moore’s Law, the rule that says the number of transistors on computer chips will double every two years.

    2
    Professor Schoelkopf, left, and Prof. Michel Devoret working on a device that can reach extremely low temperatures to allow a quantum computing device to function. Credit Roger Kisby for The New York Times

    “Schoelkopf’s Law started as a joke, but now we use it in many of our research papers,” said Isaac Chuang, a professor at the Massachusetts Institute of Technology. “No one expected this would be possible, but the improvement has been exponential.”

    These superconducting circuits have become the primary area of quantum computing research across the industry. One of Mr. Schoelkopf’s former students now leads the quantum computing program at IBM. The founder of Rigetti Computing studied with Michel Devoret, one of the other Yale professors behind Quantum Circuits.

    In recent months, after grabbing a team of top researchers from the University of California, Santa Barbara, Google indicated it is on the verge of using this method to build a machine that can achieve “quantum supremacy” — when a quantum machine performs a task that would be impossible on your laptop or any other machine that obeys the laws of classical physics.

    There are other areas of research that show promise. Microsoft, for example, is betting on particles known as anyons. But superconducting circuits appear likely to be the first systems that will bear real fruit.

    The belief is that quantum machines will eventually analyze the interactions between physical molecules with a precision that is not possible today, something that could radically accelerate the development of new medications. Google and others also believe that these systems can significantly accelerate machine learning, the field of teaching computers to learn tasks on their own by analyzing data or experiments with certain behavior.

    A quantum computer could also be able to break the encryption algorithms that guard the world’s most sensitive corporate and government data. With so much at stake, it is no surprise that so many companies are betting on this technology, including start-ups like Quantum Circuits.

    The deck is stacked against the smaller players, because the big-name companies have so much more money to throw at the problem. But start-ups have their own advantages, even in such a complex and expensive area of research.

    “Small teams of exceptional people can do exceptional things,” said Bill Coughran, who helped oversee the creation of Google’s vast internet infrastructure and is now investing in Mr. Schoelkopf’s company as a partner at Sequoia. “I have yet to see large teams inside big companies doing anything tremendously innovative.”

    Though Quantum Circuits is using the same quantum method as its bigger competitors, Mr. Schoelkopf argued that his company has an edge because it is tackling the problem differently. Rather than building one large quantum machine, it is constructing a series of tiny machines that can be networked together. He said this will make it easier to correct errors in quantum calculations — one of the main difficulties in building one of these complex machines.

    But each of the big companies insist that they hold an advantage — and each is loudly trumpeting its progress, even if a working machine is still years away.

    Mr. Coughran said that he and Sequoia envision Quantum Circuits evolving into a company that can deliver quantum computing to any business or researcher that needs it. Another investor, Canaan’s Brendan Dickinson, said that if a company like this develops a viable quantum machine, it will become a prime acquisition target.

    “The promise of a large quantum computer is incredibly powerful,” Mr. Dickinson said. “It will solve problems we can’t even imagine right now.”

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Advertisements
     
  • richardmitnick 7:28 am on November 10, 2017 Permalink | Reply
    Tags: , , , PROTACs-Proteolysis Targeting Chimeras, Yale   

    From Yale: “Cellular clean-up can also sweep away forms of cancer” 

    Yale University bloc

    Yale University

    November 9, 2017
    Bill Hathaway

    1
    Cells treated (right) or untreated (left) with a PROTAC that degrades the target protein (green). No image credit.

    Two new research papers reinforce the benefits of a novel therapy that hijacks the cell’s own protein degradation machinery to destroy cancer cells, Yale researchers report Nov. 9 in the journal Cell Chemical Biology.

    The new approach to drug discovery, called Proteolysis Targeting Chimeras or PROTACs, was developed in the laboratory of Craig Crews, the Lewis B. Cullman Professor of Molecular, Cellular, and Developmental Biology, professor of chemistry and pharmacology, as well as executive director of the Yale Center for Molecular Discovery.

    The system engages the cell’s own protein degradation machinery to destroy targeted proteins by tagging them for removal. Most drugs are based on the ability of small molecules to bind to and block the function of disease-causing proteins, but some proteins are resistant to such intervention.

    “This system will help us change the current small-molecule drug paradigm that fails to target 75% of rogue proteins,” said Crews, scientific founder of Arvinas LLC, the New Haven biotechnology company developing the concept.

    The first paper, [Cell Chemical Biology] shows for the first time that PROTAC system can target mutant RTK proteins, which have been linked to several forms of cancer. The second paper [Cell Chemical Biology] proves that the PROTAC system can target rogue proteins with greater specificity than traditional approaches.

    Yale’s George M. Burslem and Blake E. Smith are first authors of the first paper. Smith and Yale’s Daniel P. Bondeson are co-first authors of the second paper.

    The two papers were primarily funded by the National Institutes of Health. Crews is a shareholder of Arvinas, which also provided researchers to the projects.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Yale University Campus

    Yale University comprises three major academic components: Yale College (the undergraduate program), the Graduate School of Arts and Sciences, and the professional schools. In addition, Yale encompasses a wide array of centers and programs, libraries, museums, and administrative support offices. Approximately 11,250 students attend Yale.

     
  • richardmitnick 10:16 am on September 20, 2017 Permalink | Reply
    Tags: , , , , Is the Milky Way an ‘outlier’ galaxy, Yale   

    From Yale: “Is the Milky Way an ‘outlier’ galaxy? Studying its ‘siblings’ for clues” 

    Yale University bloc

    Yale University

    September 20, 2017
    Jim Shelton

    1
    A three-color optical image of a Milky Way sibling. (Courtesy of Sloan Digital Sky Survey)

    The most-studied galaxy in the universe — the Milky Way — might not be as “typical” as previously thought, according to a new study.

    Milky Way NASA/JPL-Caltech /ESO R. Hurt

    The Milky Way, which is home to Earth and its solar system, is host to several dozen smaller galaxy satellites. These smaller galaxies orbit around the Milky Way and are useful in understanding the Milky Way itself.

    Early results from the Satellites Around Galactic Analogs (SAGA) Survey indicate that the Milky Way’s satellites are much more tranquil than other systems of comparable luminosity and environment. Many satellites of those “sibling” galaxies are actively pumping out new stars, but the Milky Way’s satellites are mostly inert, the researchers found.

    This is significant, according to the researchers, because many models for what we know about the universe rely on galaxies behaving in a fashion similar to the Milky Way.

    “We use the Milky Way and its surroundings to study absolutely everything,” said Yale astrophysicist Marla Geha, lead author of the paper, which appears in The Astrophysical Journal. “Hundreds of studies come out every year about dark matter, cosmology, star formation, and galaxy formation, using the Milky Way as a guide. But it’s possible that the Milky Way is an outlier.”

    The SAGA Survey began five years ago with a goal of studying the satellite galaxies around 100 Milky Way siblings. Thus far it has studied eight other Milky Way sibling systems, which the researchers say is too small of a sample to come to any definitive conclusions. SAGA expects to have studied 25 Milky Way siblings in the next two years.

    Yet the survey already has people talking. At a recent conference where Geha presented some of SAGA’s initial findings, another researcher told her, “You’ve just thrown a monkey wrench into what we know about how small galaxies form.”

    “Our work puts the Milky Way into a broader context,” said SAGA researcher Risa Wechsler, an astrophysicist at the Kavli Institute at Stanford University. “The SAGA Survey will provide a critical new understanding of galaxy formation and of the nature of dark matter.”

    Wechsler, Geha, and their team said they will continue to improve the efficiency of finding satellites around Milky Way siblings. “I really want to know the answer to whether the Milky Way is unique, or totally normal,” Geha said. “By studying our siblings, we learn more about ourselves.”

    Other SAGA team members are Yao-Yuan Mao of the University of Pittsburgh, Erik Tollerud from the Space Telescope Science Institute, Benjamin Weiner of the University of Arizona, Rebecca Bernstein and Yu Lu of the Carnegie Institution for Science, Ben Hoyle of the Max Planck Institute for Extraterrestrial Physics, Sebastian Marchi and Ricardo Munoz of the University of Chile, and Phil Marshall of SLAC National Accelerator Laboratory. All are co-authors of the study.

    More information about SAGA can be found here: http://sagasurvey.org.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Yale University Campus

    Yale University comprises three major academic components: Yale College (the undergraduate program), the Graduate School of Arts and Sciences, and the professional schools. In addition, Yale encompasses a wide array of centers and programs, libraries, museums, and administrative support offices. Approximately 11,250 students attend Yale.

     
  • richardmitnick 9:17 pm on July 19, 2017 Permalink | Reply
    Tags: , , Helen Caines, , , Yale   

    From Yale: Women in STEM -“Yale’s Helen Caines takes a leadership role in international STAR experiment” 

    Yale University bloc

    Yale University

    July 12, 2017

    Jim Shelton
    james.shelton@yale.edu
    203-361-8332

    1
    The left half of this image shows the Solenoidal Tracker at RHIC. It is a detector that specializes in tracking the thousands of particles produced by each ion collision at RHIC. The right half of the image shows the end view of a collision of two 30-billion electron-volt gold beams in the STAR detector at RHIC. (Image courtesy of STAR)

    BNL RHIC Campus

    BNL/RHIC Star Detector

    BNL RHIC PHENIX

    Helen Caines has spent much of her professional life immersed in cosmic soup.

    While other physicists have chased gravitational waves, cultivated qubits, and mused about dark matter, Caines has focused squarely on the thick glop of particles that transformed into nuclear matter in the first milliseconds after the Big Bang. Through studying these particles, Caines believes, humanity can come to understand the basic processes that formed the early universe at that instant.

    Now Caines is a leading voice in explaining how much we’ve learned so far and what is to come. On July 1, she became co-spokesperson for the STAR experiment, an international collaboration of more than 600 physicists searching for the theorized “critical point” that transformed the universe from a soup of quarks into what we know as matter today.

    “We’re doing very exciting physics, things we never dreamed we’d be able to do when we started,” said Caines, an associate professor of physics and member of Yale’s Wright Lab. “STAR is a testament to how innovative a collaboration can be. We have the whole range of experience, from undergraduates to emeritus professors working with us.”

    The STAR experiment is focused on the dense, hot soup of quarks and gluons — known as the quark-gluon plasma — that is believed to have existed ten millionths of a second after the Big Bang. These conditions can be recreated in the laboratory by colliding heavy ions and studying the reactions — an endeavor that still amazes Caines even after more than 20 years of research.

    “It’s just so intriguing that you can smash heavy ions together and actually learn something about the early universe from it,” she said. “It’s like smashing two automobiles together and then trying to determine the make and model of each one.”

    2
    Helen Caines will co-lead the STAR experiment’s investigation of what happened ten millionths of a second after the Big Bang. (Photo by Michael Marsland)

    STAR launched in 1991 and is based at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory.


    The experiment began collecting data in 2000. More than 60 institutions in 13 countries are part of STAR.

    Yale’s involvement in the STAR experiment runs deep. Zhangbu Xu, co-spokesperson with Caines, has a Yale Ph.D., and Yale physics professor John Harris was the founding spokesperson, serving from 1991 until 2002. Current Yale collaborators, along with Caines and Harris, are emeritus professor Jack Sandweiss; adjunct professor Thomas Ullrich; graduate students Stephen Horvat, Daniel Nemes, and David Stewart; senior research scientist Richard Majka; research scientist Nikolai Smirnov; and postdoctoral associates Saehanseul Oh and Li Yi.

    “Yale has been committed to heavy ion physics research since the founding by professor D. Allan Bromley of the original Wright Nuclear Structure Laboratory in 1966 and its various upgrades of its tandem van de Graaff accelerators,” Harris said. Yale became a member institution of the STAR experiment in 1996, when Harris arrived on campus.

    Caines joined the experiment in 1996 as well. Her work involves measuring the high-momentum particles that are produced when ultra-relativistic heavy ions are collided. Specifically, she focuses on the particles’ movement through the surrounding soup. The work is helping scientists start to understand the properties and characteristics of a new state of matter in transition.

    This is where the so-called “critical point” becomes essential to physicists. Caines has been a major proponent for a program at RHIC called Beam Energy Scan, which has successfully concluded its first phase of experiments and is in the middle of its analysis.

    “BES covers the full range of collision energies at RHIC with the primary goal of potentially discovering a critical point that is predicted to exist in the phase diagram of nuclear matter,” Harris said. “At this critical point nuclear matter transforms into a plasma of quarks and gluons in a first order phase transition, where nuclear particles as we know them coexist for an instant with quarks and gluons in a very hot phase, about 100,000 times hotter than our Sun.”

    Caines will co-lead STAR in its continuing investigation of this nuclear phase and help lead a second phase of experiments over the next few years. She and Yale graduate student Horvat have identified an approximate region in collision energy and temperature where researchers may find the critical point — a region where the hotter phase of quarks and gluons gives way to the cooler nuclear phase.

    Caines’ colleagues say she is well suited to her new role.

    “These large collaborations require a lot from a spokesperson,” said Sarah Demers, the Horace Taft Associate Professor of Physics at Yale and a member of the ATLAS experiment at CERN’s Large Hadron Collider in Geneva, Switzerland. “You need to be a physics detector expert, a physics analysis expert, and you need to be able to keep your colleagues inspired and behind a common plan. Helen is an excellent physicist, and she knows how to lead a team.”

    Caines received her Ph.D. from the University of Birmingham, U.K., in 1996. She was appointed assistant professor at Yale in 2004 and promoted to associate professor in 2010. She is a faculty member of Yale’s Wright Lab.

    Part of the satisfaction of her job, she said, is the opportunity to be surprised even after decades of research. The STAR experiment exemplifies this, she explained.

    “We’re at a very interesting stage,” Caines said. “We think we may find a place in nuclear matter, where things go wild.”

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Yale University Campus

    Yale University comprises three major academic components: Yale College (the undergraduate program), the Graduate School of Arts and Sciences, and the professional schools. In addition, Yale encompasses a wide array of centers and programs, libraries, museums, and administrative support offices. Approximately 11,250 students attend Yale.

     
  • richardmitnick 1:29 pm on July 18, 2017 Permalink | Reply
    Tags: , , , Yale   

    From Yale: “Predicting Human Behavior Using the Brain’s Unique Signature” 

    Yale University bloc

    Yale University

    July 4, 2017
    Joshua Mathew

    1

    Following centuries of curiosity and uncertainty about the human brain, a recent neuroimaging study [Nature Protocols] will provide us with a way to study the live human brain non-invasively. Prior to the advent of neuroimaging, neuroscientists relied solely on post-mortem, or after death, autopsies to gain insight into the workings of the brain. By contrast, neuroimaging employs a variety of techniques to structurally or functionally image the brain without surgical intervention. A multidisciplinary team of Yale researchers has developed connectome-based predictive modeling (CPM), a computational model capable of predicting human behavior based on how one’s brain is wired.

    Some commonly used brain imaging techniques include computed tomography (CT) scanning, function magnetic resonance imaging (fMRI), and electroencephalography (EEG). fMRI measures brain activity by detecting changes in oxygenated blood flow through specific areas of the brain. Specifically, the ability to detect these changes by fMRI takes advantage of the difference in the magnetic properties of oxygenated and deoxygenated blood. CPM uses fMRI to observe activity in specific regions of the brain and subsequently derive brain connectivity data for use in predicting an individual’s behavior.

    The human connectome is a network of neural connections between different regions of the brain. These connections can be determined by identifying regions with simultaneous activity in the brain. The model developed by Yale researchers can characterize these neural connections more comprehensively by utilizing a connectivity matrix acquired from fMRI data. In a nutshell, each row in this matrix represents one of 300 regions of interest in the brain, and the data within each row describe the functional relationships between this region and the remaining 299 regions. Since humans have unique brain connectivity, and thus unique connectivity matrices, your brain’s functional connectivity can be used to predict various aspects of your behavior. CPM provides a way to extract that information and interpret it in meaningful ways.

    The predictive model is constructed by gathering connectivity matrices from many people, and is then used to predict behavioral traits of a new person based on their connectivity matrix. The predictive power of CPM has immense clinical significance. Matrix data can be used to predict and analyze whether an individual has paranoia, delusions, schizophrenic symptoms, and other conditions. Additionally, psychiatric disorders could be more effectively diagnosed with the help of CPM. The current diagnostic protocol for such disorders, the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), has been met with mixed results since categorization of patients is based solely on identifiable symptoms. Implementing CPM for diagnostic purposes could allow for more thorough and scientific categorization that could ultimately improve the quality of mental health care.

    Although CPM has not yet reached the stage of clinical application, future directions for this research are boundless. According to Professor Todd Constable, senior author of the study, one such direction could include identifying circuits that function aberrantly in certain diseases. Mechanistically understanding these diseases would in turn contribute to the development of more personalized and targeted treatments. “CPM has already been demonstrated to predict one’s fluid intelligence and attentive performance,” said Constable, who believes that many other traits can be similarly predicted. Another question that has yet to be answered is how the brain’s connectivity changes over time with aging and development. In contrast to DNA, our genetic code which is relatively static in comparison, brain connectivity is much more dynamic. This dynamism further challenges our efforts to study the brain.

    The novelty of CPM lies in the fact that it is the first whole-brain connectome study of its kind. Up until recently, a major limitation for connectivity research had been an inadequate amount of individual connectome data from which to develop models for predicting complex behaviors. While previously only local brain connectivity could be studied given the amount of data available, the launch of the Human Connectome Project (HCP) in 2009 has supplied a mass of connectome data that allows whole-brain connectivity studies to be done for the first time. HCP is a large-scale effort to collect and share human connectome data in order to address fundamental questions about the functional connectivity of the human brain. To further this goal, the Yale researchers have published an algorithm for implementing CPM to build predictive models. This provides researchers around the world with the tools to contribute to the ongoing study of the human brain using predictive modeling.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Yale University Campus

    Yale University comprises three major academic components: Yale College (the undergraduate program), the Graduate School of Arts and Sciences, and the professional schools. In addition, Yale encompasses a wide array of centers and programs, libraries, museums, and administrative support offices. Approximately 11,250 students attend Yale.

     
  • richardmitnick 1:16 pm on July 12, 2017 Permalink | Reply
    Tags: , , HAYSTAC - Haloscope at Yale Sensitive To Axion Cold Dark Matter, , , Yale   

    From Yale: “Needle in a HAYSTAC” 

    Yale University bloc

    Yale University

    July 5, 2017
    Elizabeth Ruddy

    1
    No image caption or credit.

    Imagine searching for a needle in a haystack. The needle weighs about 100 billion times less than an electron and has no charge. It acts like a wave rather than a particle, and the haystack is the size of our universe. Needles like this may exist in the tens of trillions in every cubic centimeter of space—the trick is proving that they’re there.

    That is the mission of the HAYSTAC Project at Yale, which stands for the Haloscope at Yale Sensitive To Axion Cold Dark Matter. HAYSTAC is a collaboration between Yale University, University of California, Berkeley and University of Colorado, Boulder. The project is based here in the Wright Laboratory, lead by Professor Steve Lamoreaux and a team of Yale scientists and graduate students. The scientists began their project about five years ago and released their first results this past February in The Physics Review Letters. The first author was Yale graduate student Ben Brubaker.

    “The goals of the experiment are to detect dark matter, or failing that, to at least rule out some possible models for what dark matter is,” explained Brubaker. “In simplest terms, dark matter started out as an astrophysics question: that is, there is more mass in the universe than can be accounted for by the mass we can see [through] all the wavelengths we can detect: visible light, radio waves, ultraviolet.” Dark matter is the “invisible” matter.

    The HAYSTAC project is dedicated specifically to the detection of the axion, a subatomic particle that was proposed in 1983 as a likely candidate for dark matter. Like the aforementioned needle, axions are theorized to have almost miniscule mass, no charge, and no spin. Based on the gravitational movement of stars and galaxies, we know that 80 percent of the matter in our universe is dark matter, but axions interact with other matter so weakly they become almost impossible to detect. Because they are so light, they have very little energy and behave more like waves than particles. As a result, the scientists must employ an unusual identification strategy to find them.

    2
    The HAYSTAC axion detector probes the universe for axions, a potential candidate for dark matter. No image credit.

    The HAYSTAC detection device essentially produces a magnetic field that converts the axions to photons. The frequency of oscillation of the photons is determined by the mass of the axion. Therefore, when the detector is tuned in to one specific frequency at a time, it can amplify these oscillations to make them detectable.

    “Our detector is in essence a tunable radio receiver, and we painstakingly tune the receiving frequency looking for an increase in noise. It is like driving through a desert looking for a station on the car radio: you tune slowly in hopes of finding something,” said Professor Lamoreaux, the head of the project.

    In the February report, the team demonstrated its recent breakthroughs in design: they had achieved sufficient sensitivity to test out much higher frequencies in the potential mass range than ever before. By incorporating technology from other fields such as quantum electronics, Lamoreaux and his colleagues have made the detector colder and quieter than any of its contemporaries, eliminating as much of the background noise as possible. According to Brubaker, the device is kept at about 0.1 degree Celsius above absolute zero, the unattainable temperature at which atoms physically stop moving. Freezing temperatures are critical for sensitivity because a major source of noise is thermal radiation: photons being shed by matter and interfering with the detection of axions.

    According to Professor Lamoreaux, their detector is currently the most sensitive radio receiver ever built. “Imagine a match lit on the surface of the Moon…the rate of energy entering the pupil of your eye, when the match is viewed from the Earth, is about the level of sensitivity we achieve.”

    The size of the detector scales inversely with the mass range being tested, so the Wright Lab instrument will only be able to search a small portion of the wide range of possible dark matter masses. However, the team has proven they have a design with the sensitivity capability necessary to perform these sweeps. Their design is a pioneering model for the future.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Yale University Campus

    Yale University comprises three major academic components: Yale College (the undergraduate program), the Graduate School of Arts and Sciences, and the professional schools. In addition, Yale encompasses a wide array of centers and programs, libraries, museums, and administrative support offices. Approximately 11,250 students attend Yale.

     
  • richardmitnick 11:03 am on July 10, 2017 Permalink | Reply
    Tags: , , , eGaIn a liquid alloy of indium and gallium, Magnetic Liquid Metals, The Earth's liquid outer core made of iron is crucial to creating Earth’s magnetic field, University of Maryland Three Meter dynamo experiment, Yale   

    From Yale: “Study of the Center of the Earth” 

    Yale University bloc

    Yale University

    June 30, 2017
    Sonia Wang

    1
    Study of the Center of the Earth | Yale Scientific

    What would you do with two million dollars? Chances are dim that your first answer would be to build and buy enough liquid sodium to fill a three-meter radius spherical tank. But for some scientists, this investment—the University of Maryland Three Meter dynamo experiment—paid off, serving as a key step to understanding the age-old question of how Earth’s magnetic field is generated.

    Earth’s magnetic field not only shields us from the sun’s damaging radiation, but also helps us navigate the Earth. Geophysicists have long studied the magnetic field created by Earth’s liquid core, but attempts to re-create them in the lab have previously been unsuccessful due to the prohibitively high costs of building equipment to do so.

    However, in a study published in January[Physical Review Fluids], a team of Yale researchers in Mechanical Engineering Professor Eric Brown’s lab developed a method for producing liquid metal with improved magnetic properties. The researchers created a protocol to create these Magnetic Liquid Metals (MLM) after studying a suspension of magnetic iron particles in eGaIn, a liquid alloy of indium and gallium. Such a technique could enable researchers to conduct dynamo experiments, which model the generation of Earth’s magnetic field, on a far smaller size scale.

    Magnetic Field’s Liquid Beginnings

    By studying earthquakes as they travel through the planet, seismologists know that the Earth has a fluid outer core surrounding a solid iron inner core. The liquid outer core, made of iron, is crucial to creating Earth’s magnetic field and is an example of a magnetohydrodynamic (MHD) phenomenon—magnetic properties resulting from an electrically conductive fluid. Movement of the outer core in the presence of Earth’s magnetic field induces electrical currents, which then create their own magnetic field aligning with Earth’s overall magnetic field. This process sustains itself and allows for the maintenance of Earth’s magnetic field over the years.

    2
    The Earth’s magnetic field is responsible for phenomenon such as the Northern Lights, which occurs when the sun’s radiation is deflected by the magnetic field and collides with atmospheric particles. Image courtesy of Kristian Pikner, Wikimedia Commons.

    Magnetohydrodynamic phenomena only occur at a high magnetic Reynolds number, which describes the magnetohydrodynamic properties of an object; at a high Reynolds number, MHD phenomena are more likely. The magnetic Reynolds number depends on several properties, such as the system size, the fluid velocity, electrical conductivity, and magnetic susceptibility—the response of the fluid to a magnetic influence. Something as large as a planet would have an extremely high Reynolds number, making MHD phenomena more natural. However, re-creating such phenomena in a laboratory setting is extremely difficult, requiring materials with high magnetic and electrical properties.

    Traditional studies of MHD have used liquid metals and plasmas because they have the highest electric conductivities of any known materials. Liquid sodium has the highest conductivity and has been used to create a dynamo experiment in the past, but is both expensive and dangerous; sodium reacts explosively with water and needs to be heated above its high melting temperature. Looking for a safer and easier alternative, the researchers sought to use a different liquid metal base for the study.

    However, as noted before, other factors such as the magnetic susceptibility also affect the Reynolds number. Despite having a good electrical conductivity, pure eGaIn has a low magnetic susceptibility and therefore a low Reynolds number. To boost the Reynolds number, the researchers proposed creating a new material by suspending magnetic particles in liquid metals to increase their magnetic susceptibility and take advantage of the liquid metals natural high conductivity.

    Acid’s Key Role

    While scientists have previously attempted to suspend magnetic particles in liquid metals, they have not been very successful because of metallic oxidation. The oxidation of the metal causes a new “rusted” oxidation layer on the liquid metal, with its own set of properties. As this layer is more solid, it prevents some of the delicate suspension effects.

    3
    eGaIn shows stronger magnetic properties than liquid sodium. Image courtesy of Florian Carle.

    Initially, stirring iron particles into the liquid eGaIn failed to create a successful suspension, since a solid oxide layer formed at the surface of the liquid upon exposure to air. Despite vigorous stirring to break the oxide skin, the particles clung to the oxide skin due to the strength of the interactions between the two layers.

    Seeking solutions to this problem, the scientists used hydrochloric acid (HCl), at a dangerously low pH of 0.69 capable of corroding skin, as a chemical cleaner or purifying agent; in eGaIn, hydrochloric acid removes the oxide layer on the liquid metal and iron particles, allowing for more liquid-like properties in the metal and increasing the conductivity of the iron particles. The suspension process was successful after the researchers added enough HCl to cover the metals and prevent further contact with air.

    Design Your Own Fluid

    The new material has increased magnetohydrodynamic properties compared to the original eGaIn. The resulting MLM had a Reynolds number over 5 times higher than that of pure liquid metal, or two times higher than liquid sodium. Thus, a dynamo experiment that would previously have required a three-meter radius tank might be possible on a much smaller size scale—10 square centimeters rather than three meters. “Until this study, no one thought about doing dynamo experiments with eGaIn because the quantity needed for these experiments make it cost prohibitive,” said Florian Carle, the lead author of the paper.

    Furthermore, certain properties of the MLM can be customized for different purposes and different applications. As long as the conductivity of the iron particles you would like to suspend is higher than that of the liquid metal base, nearly any material can be used for the liquid and suspended particles. “It’s basically Design Your Own Fluid…you can suspend silver, graphene, diamond…you can tune the size of the particles within this huge range,” Carle said. Changing the quantity of iron particles in eGaIn will modify the material viscosity—the more particles, the more viscous the fluid. Furthermore, changing the type of particle used can further affect the conductivity and magnetic properties of the material; using highly conductive particles will increase conductivity, and using magnetic particles like iron or steel can increase magnetic properties.

    The applications are myriad. Separately controlling the viscosity and the magnetic properties of the material will allow scientists to isolate the effects of magnetohydrodynamics, which is indicated by the Reynolds number, and turbulence, a measure affected by fluid viscosity and velocity that indicates how chaotic the flow of the material is.

    Carle designed the paper to be easily accessible, so that even a scientist without special training could re-create the material. He hopes that more scientists will apply the procedure to their research: “Now that we can tune the properties…hopefully people will start picking up on that and be able to use that. I hope in the near future we will see more and more experiments using MLMs,” Carle said.

    Of Sustainability and Superfluids

    Though Carle has moved on to work at the Yale Quantum Institute, research continues in the Brown lab on the material. One challenge the group is investigating is in keeping the magnetic liquid metals fresh during storage: after six months of storage, samples exhibited a loss in magnetic susceptibility as the hydrochloric acid slowly ate away at the iron particles.

    “It’s a bit of a conflict, since you need to protect the eGaIn with HCl, but then the HCl will eat the iron,” Carle said. Further research is being done to develop storage methods for eGaIn, including solidifying the samples or removing HCl to allow formation of a protective oxide layer on the surface of the fluid during storage.

    Carle further speculates that there are applications beyond MHD and dynamo experiments, since it is a customizable new material. And perhaps an MLM could eventually be created out of sodium, which has the highest electric conductivity of any known liquid metal. Adding magnetic particles to that suspension could allow scientists to attain a Reynolds number off the charts. “You would have a superfluid…maybe we would see phenomena we haven’t seen anywhere before,” Carle said.

    Featured Art by Isa del Toro Mijares

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Yale University Campus

    Yale University comprises three major academic components: Yale College (the undergraduate program), the Graduate School of Arts and Sciences, and the professional schools. In addition, Yale encompasses a wide array of centers and programs, libraries, museums, and administrative support offices. Approximately 11,250 students attend Yale.

     
  • richardmitnick 11:49 am on July 7, 2017 Permalink | Reply
    Tags: , , , , Yale   

    From Yale: “A cosmic barbecue: Researchers spot 60 new ‘hot Jupiter’ candidates” 

    Yale University bloc

    Yale University

    July 6, 2017

    Jim Shelton
    james.shelton@yale.edu
    203-361-8332

    1

    Yale researchers have identified 60 potential new “hot Jupiters” — highly irradiated worlds that glow like coals on a barbecue grill and are found orbiting only 1% of Sun-like stars.

    Hot Jupiters constitute a class of gas giant planets located so close to their parent stars that they take less than a week to complete an orbit.

    Second-year Ph.D. student Sarah Millholland and astronomy professor Greg Laughlin identified the planet candidates via a novel application of big data techniques. They used a supervised machine learning algorithm — a sophisticated program that can be trained to recognize patterns in data and make predictions — to detect the tiny amplitude variations in observed light that result as an orbiting planet reflects rays of light from its host star.

    Millholland recently presented the research at a Kepler Science Conference at the NASA Ames Research Center in California. She and Laughlin are authors of a study about the research, which has been accepted for publication in the Astronomical Journal.

    The Yale technique pioneers a new discovery method that identifies more planets from the publicly available Kepler data, said the researchers.

    The Doppler velocity method is a well-established technique that enables the detection of wobbling motion in a star due to the gravitational influence of an orbiting planet. Since hot Jupiters are so massive and close to their stars, the stellar wobbles they induce are large and readily detectable.

    A new, Yale-designed instrument known as EXPRES, which is being installed on the Discovery Channel Telescope in Arizona, may attempt to make confirmations later this year.

    3
    NSF funded Extreme Precision Spectrograph, EXPRES. The spectrograph will be commissioned at the Discovery Channel Telescope, part of the Lowell Observatory, near Flagstaff, Arizona

    Discovery Channel Telescope at Lowell Observatory, Happy Jack AZ, USA

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Yale University Campus

    Yale University comprises three major academic components: Yale College (the undergraduate program), the Graduate School of Arts and Sciences, and the professional schools. In addition, Yale encompasses a wide array of centers and programs, libraries, museums, and administrative support offices. Approximately 11,250 students attend Yale.

     
  • richardmitnick 9:50 am on July 3, 2017 Permalink | Reply
    Tags: , , Yale   

    From Yale: “Expanding the Quantum Computing Toolbox” 

    Yale University bloc

    Yale University

    January 17, 2017 [Just found this in social media.]
    Noah Kravitz

    In 2011, Canadian tech company D-Wave stunned the world by announcing that it would market a functioning quantum computer. Soon, companies ranging from Google to NASA bought versions of the device, and scientists began scrambling to evaluate what potentially was the biggest technological breakthrough of the century. One third-party test, in which the new quantum computer solved a complex math problem 3,600 times faster than a cutting-edge IBM supercomputer, seemed to substantiate D-Wave’s claims of quantum computation. Other tests found no evidence of quantum activity at all.

    Quantum computing, an idea which has captivated physicists and computer scientists alike since its conception in the 1980s, has proven difficult to realize in practice. Because quantum computers rely on the uncertainty built into the laws of quantum physics, they are extremely sensitive to their environments. A small imperfection in even a single component of the design can be devastating. One technical challenge is that heat energy can disrupt the fragile quantum states, so quantum technology is usually cooled almost to absolute zero (-273 degrees Celsius). D-Wave’s quantum computer is small enough to hold in the palm of your hand but has to be housed in a 10-foot-tall refrigerator.

    Yale researchers, led by Professor of Electrical Engineering and Physics Hong Tang, have developed a new version of a device called a piezo-optomechanical resonator that could allow quantum computers to operate at higher temperatures. The paper [Physical Review Letters], which is co-authored by graduate students Xu Han and Chang-Ling Zou, describes an improved method of connecting information in physical and electrical domains. This advance could be used as the basis for reliable memory storage for quantum computers—an important step towards stronger quantum computing.

    1
    D-Wave’s putative quantum computer made headlines as possibly realizing decades’ worth of theoretical physics research. Here, qubits are assembled on a circuit board, much like the layout of a classical computer. Image courtesy of Wikipedia

    From Schrodinger’s cat to national security

    Quantum computing fundamentally differs from classical computing in that it relies on the non-intuitive quantum properties of light and matter. In familiar classical computation, information is stored as bits which can take on the values 0 and 1—they are simple on/off electrical switches, and it is easy to check their positions. The computer then performs tasks using sequences of logical operations on the bits. For example, it might say that if bit A is 0, then bit B should be set to 0, but if bit A is 1, then bit B should be set to 1; or that bit C should be set to 1 only if bits A and B are different.

    In quantum computing, by contrast, the situation is not so straightforward. First of all, information is stored in qubits (short for “quantum bits”) which have more than two possible values: 0, 1, and a combination of 0 and 1. These qubits are particles with distinct measurable quantum states corresponding to “0” and “1,” but one of the principles of quantum physics is that sometimes we can predict the result of a measurement only in terms of probabilities. So in quantum mechanics, even though sometimes we might know that we will always measure the particle as “0,” there can also exist a scenario in which there is a 50 percent chance of finding the particle in the “0” state and a 50 percent chance of finding it in the “1” state. The surprising part is that, mathematically speaking, the latter particle is actually in both states equally until we measure it as being in one or the other, and it is meaningful to think of such a qubit as having value ½ representing a “mixed” state even though ½ is not a possible measurement.

    Another useful property of quantum mechanics called entanglement links the measurements of different particles. For example, if particles A and B are entangled, then we might know that whenever we measure both particles, we will get one “0” and one “1.” In this case, measuring one qubit immediately determines the value of the other, and it is possible to use this property to “teleport” information!

    2
    Unlike classical bits, which have only two possible values, qubits have a range of values from 0 to 1. In this common model of a qubit (where the North pole of the sphere represents the “0” state and the South pole the “1” state), the state of the qubit can be visualized as a point on the surface of the sphere. For instance, the value of any point above the equator is between 0 and ½, and the value of any point below the equator is between ½ and 1. Image courtesy of Columbia Science Review

    The unique logical underpinnings of quantum computation allow quantum computer to approach old problems in new ways. Since qubits are more complex than regular bits, quantum algorithms are often more streamlined than their classical counterparts, especially when searching for optimal solutions to problems. For example, if we want to find a car that is hidden behind one door out of a million, a classical computer would have to check the doors one by one, and, in the worst-case scenario, it would have to make a million queries. A quantum computer, by contrast, can use a probabilistic algorithm to find the car in at most only a thousand queries.

    Quantum computation has potential applications in many problems that would take classical computers longer than the age of the Earth. In the best-known example of this principle of “quantum speedup,” computer scientists have created a quantum algorithm that can factor large numbers (essentially a needle-in-a-haystack problem like the car example above) exponentially faster than is possible for any classical algorithm. Although this problem may not seem very exciting, it in fact underlies many more complex processes such as cryptography. Similar principles apply to choosing cost-effective combinations of building materials and even to identifying keywords for news articles. Unsurprisingly, quantum computation is often the best way to model complex natural systems.

    We have made significant progress over the past few decades towards meeting the challenges of quantum computing. As early as the mid-1990s, we have manipulated qubits and written codes to correct spontaneous errors in quantum computers. In the 2000s, we demonstrated long-distance entanglement. In 2013, Hong Tang and his team contributed to the corpus of knowledge when they determined a method for measuring quantum systems without permanently altering them. Now, in 2016, the Tang Lab at Yale has once again expanded the quantum computing toolbox, this time in the stubbornly challenging field of information storage and transfer.

    A new approach to quantum memory

    You probably carry around in your pocket a crucial piece of the new Yale device: Smartphones contain the materials that Tang and his team used to bridge the mechanical-electrical gap. Piezoelectrics are materials, usually crystals, that accumulate charge when compressed, twisted or bent. For instance, when a piezoelectric sheet is creased, a net negative charge forms at the fold, and net positive charges form at the ends. Conversely, when an external magnetic field causes charges in a piezoelectric to move, the object responds by changing shape physically. In this way, vibrations in physical objects and electrical fields can easily be connected, or, as physicists say, coupled. Piezoelectrics in smartphones often power tiny speakers— they convert electrical signals into sound waves, which arise from physical pulses.

    The Yale piezo-optomechanical device consists of a pair of tiny resonators: a silicon wafer and a wire loop situated above it. “It is useful to think of a resonator like a tuning fork because it responds most powerfully to a particular resonant frequency,” said Han, an electrical engineering Ph.D candidate who worked on the project. The two ends of the wire loop do not quite connect, so electrical charges tend to bounce back and forth around the circle, which functions as an electrical resonator in the microwave region of the electromagnetic spectrum. The wafer, which is about as thick as five sheets of paper, functions as an acoustic, or mechanical, resonator. This resonator is coated with a thin layer of aluminum nitride, a piezoelectric material, which facilitates the exchange of oscillations—and energy— between mechanical and electrical components. “If you want to transfer information between two systems, it is necessary to have an efficient coupling mechanism,” Han said.

    3
    Professor Hong Tang (right) and graduate students Chang-Ling Zou (left) and Xu Han (not pictured) developed a piezo-optomechanical resonator that has applications to quantum memory storage. Image courtesy of Hong Tang

    The idea of coupling between mechanical and microwave electrical domains is not new; the Yale team’s innovation is achieving stronger coupling on a smaller scale. The key is using resonators with a higher frequency: Whereas other designs have used frequencies on the order of a few million oscillations per second, the Yale design runs at ten billion oscillations per second. As a result, the device is solidly in the so-called strong-coupling regime —meaning that the rate of information transfer is greater than the natural energy dissipation rates of the individual systems—and transmitted signals are clearer and longer-lasting. Yet high frequency comes at the cost of increased construction difficulties. “Since the device is small, it is more susceptible to perturbations in the environment,” Tang said. As a result, the design carefully balances considerations of compactness and robustness.

    The researchers believe that applications of their breakthrough lie mostly in the far future. “This is fundamental research, so it’s not immediately pertinent to daily life,” Han said. Instead, the piezo-optomechanical resonator’s real value is as a component of more complex systems. Because of the strong coupling achieved, it is well suited for quantum uses where “noise” from ambient heat (analogous to TV static) would otherwise be disruptive. “For high-frequency devices, the temperature requirement is not as low,” Han said. Chang-Ling Zou, a postdoctoral student in Tang’s lab, hopes to develop this strength into a basis for quantum memory storage, which is currently unfeasible at most temperatures. Small vibrating crystals would serve as physical memory, and the resonators would convert between these crystals and the computational part of the computer, which would likely operate in the microwave domain.

    The Yale team is also looking to incorporate visible light into their design. “The next step is integrating an optical resonator and using the acoustic resonator as an intermediary between microwave and optics,” Han said. Accomplishing this feat could improve computer signal processing, radio receiving efficiency, and information transmission across long distances via optical fiber cables.

    Given its versatility, the piezo-optomechanical resonator may find its way into all kinds of applications. From analyzing the stock market to sending trans-Atlantic messages, you can expect to hear more about this small device in big-time situations.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Yale University Campus

    Yale University comprises three major academic components: Yale College (the undergraduate program), the Graduate School of Arts and Sciences, and the professional schools. In addition, Yale encompasses a wide array of centers and programs, libraries, museums, and administrative support offices. Approximately 11,250 students attend Yale.

     
  • richardmitnick 4:50 pm on June 28, 2017 Permalink | Reply
    Tags: , Transferring New Energy to an Old Rule: Pushing the Boundaries of Classical Physics, Yale   

    From Yale: “Transferring New Energy to an Old Rule: Pushing the Boundaries of Classical Physics” 

    Yale University bloc

    Yale University

    January 16, 2017
    Chunyang Ding

    1
    Cover image: A synchrotron, similar to the one pictured above, was used to determine the composition of fossils, an analysis key to understanding the preservational features of the Tully Monster. Image courtesy of John O’Neill

    Time after time, brilliant scientists make claims about science’s future that prove completely wrong. In a quote often misattributed to Lord Kelvin, Albert Michelson famously declared that “there is nothing new to be discovered in physics now; all that remains is more and more precise measurement.” Classical mechanics, the tradition of physics that originated with Newton, Kepler, and Galileo, is often seen as something we already understand, and something we have understood for a long time. This is simply not true. Even today, new discoveries made with classical mechanics are transforming the world of science as we know it.

    In a recent breakthrough, a Yale physics lab shows new behaviors in a phenomenon that some had considered fully understood. Associate professor of physics Jack Harris and post-doctoral researcher Haitan Xu report in Nature their use of ultra-precise lasers and tiny vibrating sheets that appear to violate classical predictions. Their experiment, transferring energy by very slowly tuning the vibrations, has major implications for a decades-old theorem in mechanics: the adiabatic theorem. This newly discovered phenomenon occurs in all systems with friction, and may fundamentally shift the way physicists view systems.

    A dance for the ages

    Although Xu’s research focuses on how energy can be transferred between two different regions, the core of this new research deals with systems, a very general way of describing things that interact. Most things in the world are systems: the traffic through a busy city, the movement of the planets, or even a large ballroom dance.

    In a ballroom dance, each person on the dance floor obeys the rules of the dance, and as they move, they interact with other people harmoniously. There might be a set number of dance moves that eventually bring them back to the starting point. Essentially, Xu’s research found that there are certain moves that when danced “clockwise,” return you to the same position, but when danced “counter-clockwise,” present you with a new partner. This non-symmetrical form has serious implications for any system, and offers a new way that scientists could control these systems.

    1
    Any system, even our solar system, can be represented in a parameter space, where different parameters are plotted against each other. Through careful control, the Harris lab was able to navigate the parameters of their vibrating membrane around an exceptional point, showing an extension to the adiabatic theorem. Image courtesy of Sida Tang

    The research provides an extension of the adiabatic theorem, a theorem that governs how systems change as the parameters of the systems change. These parameters can be any controlled quality of the system — the dance moves performed, the tension in a wire, or the controls in a computer. The adiabatic theorem says that if the parameters are slowly restored to their original state, the system will appear to have not changed at all. This is very powerful in physics, because for a certain experiment on a system, scientists can restore previous states without being concerned exactly in what way the parameters changed. Yet, it is not very exciting. After all, you only end up where you begin.

    Imagine for a moment that we had a small dial allowing us to change the masses of Jupiter and the Sun. Through our understanding of the laws of gravity, we could predict how the orbits of the planet change if Jupiter became more massive and if the Sun became less massive. The paths of the planets may become chaotic, but the adiabatic theorem provides a simple solution: when all of the parameters are back to where they began, the system would appear to have never changed.

    However, there is one caveat to the above examples. The only way that the adiabatic theorem has been proven is through assuming systems that do not have any friction, or energy loss. Only in those cases does the adiabatic theorem work as expected. Still, physicists applied this theorem to systems with friction by assuming such systems would behave very similarly to those without friction. What physicists did not expect, however, was that the system could change completely. Although mathematicians predicted anomalies using what they called “exceptional points,” physicists were unable to see these anomalies in actual systems — until now.

    Tiny vibrating membranes

    While the previous systems may be simple to imagine, they would be nearly impossible to actually control and measure. In order to actually see the effects of the adiabatic theorem, Xu’s research involved vibrating a tiny membrane between two mirrors while using lasers both to control and to measure the vibrations of the membrane. The reason this is considered a system is because the membrane has two vibrational modes, or methods of vibration, and the frequency of each vibration can be controlled by the laser. Vibrational modes are like vertical waves and a horizontal waves that pass by each other, and can be thought of as two separate strings, each vibrating independently.

    Vibrating strings are familiar to anyone who has played a string instrument, whether it be a guitar, a violin, or an erhu. When you pluck a single string, the other strings do not react, as each string has a different resonating frequency. However, if you tune two strings to have the same resonating frequency, the vibrating energy can transfer from one string to the other. In this experiment, the resonating frequencies are being changed so that the two different strings are first tuned together, and then returned to their original resonating frequencies. If we then apply the adiabatic theorem, we would predict that whatever vibrations are in the strings now are the same as the vibrations in the strings that we started with.

    3
    The lab group, (Luyao Jiang, Haitan Xu, David Mason and Professor Jack Harris in 8, Professor Jack Harris, Haitan Xu, David Mason and Luyao Jiang in 9) pose before their experimental apparatus. Along with the Doppler group from the Vienna University of Technology, this lab was the first to discover experimental proof for the exceptional points. Image courtesy of George Iskander

    However, Xu’s research group discovered that this is not always the case in a system that has some amount of friction. In rare situations that involve the “exceptional point” in parameter space, the energy can end up transferring from the first string to the second string. Every time the parameters were changed counter-clockwise around the exceptional point, they found drastic changes to the final systems. They found that whenever the parameters created a path that encircled the exceptional point, this change happened, regardless of the actual shape of the path.

    Teleporting between different sheets

    Exceptional points are fairly difficult to imagine for a good reason: They are the result of two 2D sheets intersecting each other in a 4D space. One way to picture these exceptional points is a fire pole connecting two floors of a fire station. While each floor is distinct, they “meet” at the fire pole. However, oddly, when you walk counter-clockwise around the pole on the first floor, you would find yourself on the second floor, without having climbed the pole at all! The phenomenon here is due to the bizarre spatial geometry, similar to shapes like a Mobius strip or a Klein bottle. The exceptional points are mathematically similar, connecting surfaces that appear to be separated.

    The example with the fire station may be hard to visualize, but the actual experiment is even more abstract, as there is no actual movement around anything. Instead, when the parameters of the vibrations travel in this loop, the energy of the system shifts. The experimental group was able to quantitatively measure the energy differences in this single membrane by spying on the vibrations with a low-powered laser even as a high-powered laser changed the parameters. This research, the first of its type, provides solid evidence that the mathematicians were right: Exceptional points exist in parameter space, and physicists can utilize them to control the system.

    In the same issue of Nature, a separate group also published on this topic, but the group used a completely different method. While the Yale group was able to dynamically change the vibrations using the laser, a group from the Vienna University of Technology led by Jorg Doppler found similar effects through pre-fabricated waveguides, which are equally impressive in the ability to control waves. Together with the Xu research, these experiments provide the first empirical proof of exceptional points.

    Taking control of our world

    4
    Like a Klein bottle, the geometries of parameter space may seem to be non-orientable, allowing for this phenomenon to occur. This bizarre discovery shows experimentally what was previously hypothesized mathematically. Image courtesy of Wikimedia

    The most powerful implication of this new research may be in its application for controlling systems. The adiabatic theorem, as well as this extension of the theorem, are particularly robust. They do not seem to care what path you take, as long as you return to the same position. This property is analogous to blindly driving through a dark two-lane icy tunnel, but finding that you always end up on the right side of the road at the end. These robust theorems are extremely helpful for experiments, especially in preventing disruptions to the system. “It’s a new type of control over really pristine systems,” Harris said.

    Even the classical adiabatic theorem and its offshoots are being used to predict magnetic effects and provide a deeper understanding for many quantum phenomena. This new extension of the adiabatic theorem will provide insight for physicists as they apply it to other systems, like NMRs and MRIs. In fact, this extended adiabatic theorem, as a fundamental physical theorem, could be more broadly applied to any system — so this research could theoretically be applied to anything that can be modeled as a system. However, this isn’t the end of the line on this research for the Harris lab; they have a paper forthcoming regarding the application of this technique to very different kinds of vibrations.

    Our understanding of every branch of science is constantly evolving and changing. Just when we think we understand everything about a field, we realize that particles can interact with themselves, that the fabric of space and time can stretch, and that the universe is expanding. Classical mechanics is no different; the extended adiabatic theorem from this study shows just that. At a certain point, we might as well expect to be surprised. If you find yourself walking around a fire pole on the first floor and ending up on the second, don’t be alarmed. Bizarre Twilight Zone scenarios like that are what can help physicist control, bend, and structure our world — no matter how strange those truths may be.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Yale University Campus

    Yale University comprises three major academic components: Yale College (the undergraduate program), the Graduate School of Arts and Sciences, and the professional schools. In addition, Yale encompasses a wide array of centers and programs, libraries, museums, and administrative support offices. Approximately 11,250 students attend Yale.

     
c
Compose new post
j
Next post/Next comment
k
Previous post/Previous comment
r
Reply
e
Edit
o
Show/Hide comments
t
Go to top
l
Go to login
h
Show/Hide help
shift + esc
Cancel
%d bloggers like this: