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Quantum Tunneling Effects, Solving the Schrodinger Equation Bottleneck Recognized as Best Papers by The Journal of Chemical Physics – PRNewswire

May 6, 2020 | Author: admin

MELVILLE, N.Y., May 6, 2020 /PRNewswire/ --Two early career researchers have been announced as the winners of the inaugural Best Paper by an Emerging Investigator Award by The Journal of Chemical Physics (JCP), a publication of AIP Publishing.

Original research from Jeremy O. Richardson and Sandeep Sharma was selected by a selection committee composed of Editorial Advisory Board members from the pool of papers included in the highly selective 2019 JCP Emerging Investigators Special Collection. Richardson and Sharma were awarded $2,000 each and invited to write a Perspective article on their field for publication by The Journal of Chemical Physics.

Qualifying submissions have a principal investigator within 10 years of their graduate degree graduation date and encompass the entire scope of the journal. Submissions are currently open for the 2020 JCP Emerging Investigators Special Collection.

Jeremy O. Richardson

Jeremy O. Richardson was born in Cardiff, Wales, and holds a doctorate in chemistry from the University of Cambridge in the United Kingdom.

Throughout most of his scientific career, Richardson's research focus has been on studying molecular systems at the intersection of the classical and quantum limits. Molecules behave according to the laws of quantum mechanics, but these laws are difficult to model in computational algorithms. One way to overcome this is to ignore the quantum effects and simply simulate molecules using classical mechanics. Though efficient, this method introduces additional errors in calculations.

"My research attempts to find a compromise between these two alternatives, which we call semiclassical because they are halfway between classical and quantum in both accuracy and efficiency," said Richardson.

In the winning paper, "Instanton formulation of Fermi's golden rule in the Marcus inverted regime," which was published in The Journal of Chemical Physicson Jan. 17, 2020, Richardson and his graduate student Eric R. Heller extended the semiclassical instanton theory to calculate quantum tunneling effects in electron-transfer reactions in the Marcus inverted regime. Though tunneling is known to be an important quantum effect that allows for reactions that are energetically prohibited classically, it had been previously ignored within Marcus theory, which explains electron transfer reaction rates. A reconciliation between the two was thought to be impossible in this regime.

"This manuscript sheds interesting new light on the quantum mechanics of electron transfer in the Marcus inverted regime, where tunneling through the reaction barrier can enhance the rate of an electron transfer reaction by orders of magnitude," according to a JCP editor.

Though the paper currently serves as a proof-of-concept, the researchers plan to use their method to study to more complicated systems.

"Eric and I are delighted to have received this recognition of our work and hope that interested readers will suggest exciting applications for our new method," Richardson said.

Sandeep Sharma

Sandeep Sharma was born in Mumbai, India, and received his doctorate in chemical engineering from the Massachusetts Institute of Technology. He focused on understanding the combustion and formation processes of polycyclic aromatic hydrocarbons, the precursors to soot. Since then, his primary attention has shifted toward developing methods for calculating electronic structure theory of correlated systems.

In his winning paper, "Multireference configuration interaction and perturbation theory without reduced density matrices," which was published in The Journal of Chemical Physicson Dec. 2, 2019, Sharma and his collaborators overcame the bottleneck of prohibitively expensive calculation and memory requirements for solving the Schrdinger equation for large, complex systems of transition metal atoms. Because it is impossible to determine exact solutions for such arbitrarily complex systems, the best-case scenario is to develop a heuristic approach, consisting of a family of algorithms, each of which works on a subset of the larger system.

"The accurate calculation of electronic structure is very difficult in large, strongly correlated systems. To treat such situations, a suite of so-called 'multireference' techniques have been developed, but these approaches are costly and difficult to use for large systems," said a JCP editor. "The authors devise a stochastic means to circumvent a major bottleneck in two paradigmatic types of these established approaches, paving the way for a more facile accurate treatment of large-scale strongly correlated problems."

The work demonstrates that a class of methods previously limited to smaller molecules can be extended into more complicated systems, serving as a step toward the best-case scenario. By manipulating the equations in just the right way, the researchers transformed a single, expensive step into a series of tiny, cheap calculations.

"I am very pleased to receive this award," he said. "I have read with great interest the papers that were published in this issue, some of which were written by colleagues and friends that I know and respect, so it was all the more gratifying when the editors of The Journal of Chemical Physicstold me that my work was selected."

ABOUT THE JOURNAL

The Journal of Chemical Physicsis an international journal that publishes cutting edge research in all areas of modern physical chemistry and chemical physics. See https://aip.scitation.org/journal/jcp

ABOUT THE AWARD

The Journal of Chemical Physicsis committed to recognizing the excellent work of early career investigators. We are therefore proud to present the JCP Emerging Investigators Special Collection and the accompanying JCP Best Paper by an Emerging Investigator Awards. A subcommittee of the JCP Editorial Advisory Board, not journal editors, choose two winners from among the papers accepted to the special collection.

ABOUT AIP PUBLISHING

AIP Publishing is a wholly owned not-for-profit subsidiary of the American Institute of Physics (AIP). AIP Publishing's mission is to support the charitable, scientific and educational purposes of AIP through scholarly publishing activities in the fields of the physical and related sciences on its own behalf and on behalf of our publishing partners to help them proactively advance their missions.

SOURCE AIP Publishing

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Quantum Tunneling Effects, Solving the Schrodinger Equation Bottleneck Recognized as Best Papers by The Journal of Chemical Physics - PRNewswire

Finding the right quantum materials – MIT News

May 6, 2020 | Author: admin

The Gordon and Betty Moore Foundation has awarded MIT Associate Professor of Physics Joseph G. Checkelsky a $1.7 million Emergent Phenomena in Quantum Systems (EPiQS) Initiative grant to pursue his search for new crystalline materials, known as quantum materials, capable of hosting exotic new quantum phenomena.

Quantum materials have the potential to transform current technologies by supporting new types of electronic and magnetic behavior, including dissipationless transmission of electricity and topological protection of information. Designing and synthesizing robust quantum materials is a key goal of modern-day physics, chemistry, and materials science.

However, this task does not have a straightforward recipe, particularly as many of the most exciting quantum systems are also the most complex. The starting point can be viewed as the periodic table of the elements and the geometrically allowed ways to arrange them in a solid. The path from there to a new quantum material can be circuitous, to say the least, Checkelsky says.

In our group we are trying to come up with new methods to find our way to these new quantum systems, he says. This usually requires a fresh perspective on crystalline motifs.

One example of these unique electronic structures is the kagome crystal lattice formed when atoms of iron (Fe) and tin (Sn) combine into a pattern that looks like a Japanese kagome basket, with a repeating pattern of corner-sharing triangles. Checkelsky, together with Class of 1947 Career Development Assistant Professor of Physics Riccardo Comin, graduate students Linda Ye and Min Gu Kang, and their colleagues reported in 2018 that a compound with a 3-to-2 ratio of iron to tin (Fe3Sn2) generates Dirac fermions a special kind of electronic state supporting exotic electronic behavior protected by the topology, or geometric structure, of atoms within the material.

More recently, the MIT team and colleagues elsewherereportedinNature Materials that, in a 1-to-1 iron-tin compound, the symmetry of the kagome lattice is special, simultaneously hosting both infinitely light massless particles (the Dirac fermions) and infinitely heavy particles (which manifest experimentally as flat bands in the electronic structure of the material). These unique electronic structures in iron-tin compounds could be the basis for new topological phases and spintronic devices.

For many years, the idea that a metal with atoms arranged in a kagome lattice of corner-sharing triangles could support unusual electronic states, such as combining both massless and infinitely massive electrons, remained a textbook problem something that could be solved with equations but had not been experimentally shown in a real material. It was, Checkelsky notes, thought of as a toy model, something so simplified that it might seem unrealistic that a real lattice would do that. But something about it being so simple helps you cut to the heart of the most interesting physics, he says. By doing our best to force this into an actual crystal, we managed to bridge that gap from the abstract to the real in a quantum material.

To try to find new quantum materials is a challenge, Checkelsky says. Typically for our group, we think about different kinds of lattices that might support these interesting states. The generous support of the Gordon and Betty Moore Foundation will help us pursue new methods to stabilize these materials beyond conventional approaches giving us a chance to find exciting new materials.

It is also an opportunity to train people how to find new quantum materials, he says. This is a process that takes time, but is an important skill in the field of quantum materials and one to which I hope we can contribute.

Last year, Checkelsky led an international team to discover a new type of magnetically driven electrical response in a crystal composed of cerium, aluminum, germanium, and silicon. The researchers call this responsesingular angular magnetoresistance(SAMR).

Like an old-fashioned clock that chimes at 12 oclock and at no other position of the hands, the newly discovered magnetoresistance only occurs when the direction, or vector, of the magnetic field is pointed straight in line with the high-symmetry axis in the materials crystal structure. Turn the magnetic field more than a degree away from that axis and the resistance drops precipitously. Theseresultswere reported in the journalScience.

This unique effect, which can be attributed to the ordering of the cerium atoms magnetic moments, occurs at temperatures below 5.6 kelvins (-449.6 degrees Fahrenheit). It differs strongly from the response of typical electronic materials, in which electrical resistance and voltage usually vary smoothly as an applied magnetic field is rotated across the material.

In July 2019, Checkelsky won a Presidential Early Career Award for Scientists and Engineers (PECASE), the highest honor bestowed by the U.S. government to science and engineering professionals in the early stages of their independent research careers.

TheGordon and Betty Moore Foundationfosters pathbreaking scientific discovery, environmental conservation, patient-care improvements, and preservation of the special character of the San Francisco Bay Area. Checkelskys Moore Foundation EPiQS Initiative Grant No. GBMF9070 is administered by the Materials Research Laboratory. The Materials Research Laboratory serves interdisciplinary groups of MIT faculty, staff, and students supported by industry, foundations, and government agencies to carry out fundamental engineering research on materials. Research topics include energy conversion and storage, quantum materials, spintronics, photonics, metals, integrated microsystems, materials sustainability, solid-state ionics, complex oxide electronic properties, biogels, and functional fibers.

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Finding the right quantum materials - MIT News

Is string theory worth it? – Space.com

May 6, 2020 | Author: admin

Paul M. Sutter is an astrophysicist at SUNY Stony Brook and the Flatiron Institute, host of Ask a Spaceman and Space Radio, and author of "Your Place in the Universe." Sutter contributed this article to Space.com's Expert Voices: Op-Ed & Insights.

String theory has had a long and venerable career. Starting in the 1960s as an attempt to explain the strong nuclear force, it has now grown to become a candidate theory of everything: a single unifying framework for understanding just about all the things in and about the universe. Quantum gravity? String theory. Electron mass? String theory. Strength of the forces? String theory. Dark energy? String theory. Speed of light? String theory.

It's such a tempting, beautiful idea. But it's also been 60 years without a result, without a final theory and without predictions to test against experiment in the real universe. Should we keep hanging on to the idea?

Related: Putting string theory to the test

There's a reason that string theory has held onto the hearts and minds of so many physicists and mathematicians over the decades, and that has to do with gravity. Folding gravity into our understanding of quantum mechanics has proven fiendishly difficult not even Albert Einstein himself could figure it out. But despite all our attempts, we have not been able to craft a successful quantum description of gravity. Every time we try, the mathematics just gets tangled in knots of infinities, rending predictions impossible.

But in the 1970s, theorists discovered something remarkable. Buried inside the mathematics of string theory was a generic prediction for something called a graviton, which is the force carrier of gravity. And since string theory is, by its very construction, a quantum theory, it means that it automatically provides a quantum theory of gravity.

This is indeed quite tantalizing. It's the only theory of fundamental physics that simply includes gravity and the original string theory wasn't even trying!

And yet, decades later, nobody has been able to come up with a complete description of string theory. All we have are various approximations that we hope describe the ultimate theory (and hints of an overarching framework known as "M-theory"), but none of these approximations are capable of delivering actual predictions for what we might see in our collider experiments or out there in the universe.

Even after all these decades, and the lure of a unified theory of all of physics, string theory isn't "done."

One of the many challenges of string theory is that it predicts the existence of extra dimensions in our universe that are all knotted and curled up on themselves at extremely small scales. Suffice it to say, there are a lot of ways that these dimensions can interfold somewhere in the ballpark of 10100,000. And since the particular arrangement of the extra dimensions determines how the strings of string theory vibrate, and the way that the strings vibrate determines how they behave (leading to the variety of forces and particles in the world), only one of those almost uncountable arrangements of extra dimensions can correspond to our universe.

But which one?

Right now it's impossible to say through string theory itself we lack the sophistication and understanding to pick one of the arrangements, determine how the strings vibrate and hence the flavor of the universe corresponding to that arrangement.

Since it looks like string theory can't tell us which universe it prefers, lately some theorists have argued that maybe string theory prefers all universes, appealing to something called the landscape.

The landscape is a multiverse, representing all the 10100,000 possible arrangements of microscopic dimensions, and hence all the 10100,000 arrangements of physical reality. This is to say, universes. And we're just one amongst that almost-countless number.

So how did we end up with this one, and not one of the others? The argument from here follows something called the Anthropic Principle, reasoning that our universe is the way it is because if it were any different (with, say, a different speed of light or more mass on the electron) then life at least as we understand it would be impossible, and we wouldn't be here to be asking these big important questions.

If that seems to you as filling but unsatisfying as eating an entire bag of chips, you're not alone. An appeal to a philosophical argument as the ultimate, hard-won result of decades of work into string theory leaves many physicists feeling hollow.

Related: The history and structure of the universe (infographic)

The truth is, by and large most string theorists aren't working on the whole unification thing anymore. Instead, what's captured the interest of the community is an intriguing connection called the AdS/CFT correspondence. No, it's not a new accounting technique, but a proposed relationship between a version of string theory living in a 5-dimensional universe with a negative cosmological constant, and a 4-dimensional conformal field theory on the boundary of that universe.

The end result of all that mass of jargon is that some thorny problems in physics can be treated with the mathematics developed in the decades of investigating string theory. So while this doesn't solve any string theory problems itself, it does at least put all that machinery to useful work, lending a helping hand to investigate many problems from the riddle of black hole information to the exotic physics of quark-gluon plasmas.

And that's certainly something, assuming that the correspondence can be proven and the results based on string theory bear fruit.

But if that's all we get approximations to what we hope is out there, a landscape of universes, and a toolset to solve a few problems after decades of work on string theory, is it time to work on something else?

Learn more by listening to the episode "Is String Theory Worth It? (Part 6: We Should Probably Test This)" on the Ask A Spaceman podcast, available on iTunes and on the Web at http://www.askaspaceman.com. Thanks to John C., Zachary H., @edit_room, Matthew Y., Christopher L., Krizna W., Sayan P., Neha S., Zachary H., Joyce S., Mauricio M., @shrenicshah, Panos T., Dhruv R., Maria A., Ter B., oiSnowy, Evan T., Dan M., Jon T., @twblanchard, Aurie, Christopher M., @unplugged_wire, Giacomo S., Gully F. for the questions that led to this piece! Ask your own question on Twitter using #AskASpaceman or by following Paul @PaulMattSutter and facebook.com/PaulMattSutter.

Is string theory worth it? - Space.com

Free Will Astrology: May 6, 2020 – River Cities Reader

May 6, 2020 | Author: admin

ARIES (March 21-April 19): According to Aries author and mythologist Joseph Campbell, "The quest for fire occurred not because anyone knew what the practical uses for fire would be, but because it was fascinating." He was referring to our early human ancestors, and how they stumbled upon a valuable addition to their culture because they were curious about a powerful phenomenon, not because they knew it would ultimately be so valuable. I invite you to be guided by a similar principle in the coming weeks, Aries. Unforeseen benefits may emerge during your investigation into flows and bursts that captivate your imagination.

TAURUS (April 20-May 20): "The future belongs to those who see possibilities before they become obvious," says businessperson and entrepreneur John Sculley. You Tauruses aren't renowned for such foresight. It's more likely to belong to Aries and Sagittarius people. Your tribe is more likely to specialize in doing the good work that turns others' bright visions into practical realities. But this Year of the Coronavirus could be an exception to the general rule. In the past three months as well as in the next six months, many of you Bulls have been and will continue to be catching glimpses of interesting possibilities before they become obvious. Give yourself credit for this knack. Be alert for what it reveals.

GEMINI (May 21-June 20): For 148 uninterrupted years, American militias and the American army waged a series of wars against the native peoples who lived on the continent before Europeans came. There were more than 70 conflicts that lasted from 1776 until 1924. If there is any long-term struggle or strife that even mildly resembles that situation in your own personal life, our Global Healing Crisis is a favorable time to call a truce and cultivate peace. Start now! It's a ripe and propitious time to end hostilities that have gone on too long.

CANCER (June 21-July 22): Novelist Marcel Proust was a sensitive, dreamy, emotional, self-protective, creative Cancerian. That may explain why he wasn't a good soldier. During his service in the French army, he was ranked 73rd in a squad of 74. On the other hand, his majestically intricate seven-volume novel In Search of Lost Time is a masterpiece one of the 20th Century's most influential literary works. In evaluating his success as a human being, should we emphasize his poor military performance and downplay his literary output? Of course not! Likewise, Cancerian, in the coming weeks I'd like to see you devote vigorous energy to appreciating what you do best and no energy at all to worrying about your inadequacies.

LEO (July 23-August 22): "Fortune resists half-hearted prayers," wrote the poet Ovid more than 2,000 years ago. I will add that Fortune also resists poorly formulated intentions, feeble vows, and sketchy plans especially now, during an historical turning point when the world is undergoing massive transformations. Luckily, I don't see those lapses being problems for you in the coming weeks, Leo. According to my analysis, you're primed to be clear and precise. Your willpower should be working with lucid grace. You'll have an enhanced ability to assess your assets and make smart plans for how to use them.

VIRGO (August 23-September 22): Last year the Baltimore Museum of Art announced it would acquire works exclusively from women artists in 2020. A male art critic complained, "That's unfair to male artists." Here's my reply: Among major permanent art collections in the U.S. and Europe, the work of women makes up five percent of the total. So what the Baltimore Museum did is a righteous attempt to rectify the existing excess. It's a just and fair way to address an unhealthy imbalance. In accordance with current omens and necessities, Virgo, I encourage you to perform a comparable correction in your personal sphere.

LIBRA (September 23-October 22): In the course of my life, I've met many sharp thinkers with advanced degrees from fine universities who are nonetheless stunted in their emotional intelligence. They may quote Shakespeare and discourse on quantum physics and explain the difference between the philosophies of Kant and Hegel, and yet have less skill in understanding the inner workings of human beings or in creating vibrant intimate relationships. Yet most of these folks are not extreme outliers. I've found that virtually all of us are smarter in our heads than we are in our hearts. The good news, Libra, is that our current Global Healing Crisis is an excellent time for you to play catch up. Do what poet Lawrence Ferlinghetti suggests: "Make your mind learn its way around the heart."

SCORPIO (October 23-November 21): Aphorist Aaron Haspel writes, "The less you are contradicted, the stupider you become. The more powerful you become, the less you are contradicted." Let's discuss how this counsel might be useful to you in the coming weeks. First of all, I suspect you will be countered and challenged more than usual, which will offer you rich opportunities to become smarter. Secondly, I believe you will become more powerful as long as you don't try to stop or discourage the influences that contradict you. In other words, you'll grow your personal authority and influence to the degree that you welcome opinions and perspectives that are not identical to yours.

SAGITTARIUS (November 22-December 21): "It's always too early to quit," wrote author Norman Vincent Peale. We should put his words into perspective, though. He preached "the power of positive thinking." He was relentless in his insistence that we can and should transcend discouragement and disappointment. So we should consider the possibility that he was overly enthusiastic in his implication that we should never give up. What do you think, Sagittarius? I'm guessing this will be an important question for you to consider in the coming weeks. It may be time to re-evaluate your previous thoughts on the matter and come up with a fresh perspective. For example, maybe it's right to give up on one project if it enables you to persevere in another.

CAPRICORN (December 22-January 19): The 16th-Century mystic nun Saint Teresa of Avila was renowned for being overcome with rapture during her spiritual devotions. At times she experienced such profound bliss through her union with God that she levitated off the ground. "Any real ecstasy is a sign you are moving in the right direction," she wrote. I hope that you will be periodically moving in that direction yourself during the coming weeks, Capricorn. Although it may seem odd advice to receive during our Global Healing Crisis, I really believe you should make appointments with euphoria, delight, and enchantment.

AQUARIUS (January 20-February 18): Grammy-winning musician and composer Pharrell Williams has expertise in the creative process. "If someone asks me what inspires me," he testifies, "I always say, 'That which is missing.'" According to my understanding of the astrological omens, you would benefit from making that your motto in the coming weeks. Our Global Healing Crisis is a favorable time to discover what's absent or empty or blank about your life, and then learn all you can from exploring it. I think you'll be glad to be shown what you didn't consciously realize was lost, omitted, or lacking.

PISCES (February 19-March 20): "I am doing my best to not become a museum of myself," declares poet Natalie Diaz. I think she means that she wants to avoid defining herself entirely by her past. She is exploring tricks that will help her keep from relying so much on her old accomplishments that she neglects to keep growing. Her goal is to be free of her history, not to be weighed down and limited by it. These would be worthy goals for you to work on in the coming weeks, Pisces. What would your first step be?

Experiment: To begin the next momentous healing, tell the simple, brave, and humble truth about yourself. Testify at FreeWillAstrology.com.

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Free Will Astrology: May 6, 2020 - River Cities Reader

Free Will Astrology – Week of May 7 | Advice & Fun | Bend – The Source Weekly

May 6, 2020 | Author: admin

Here's this week's Free Will Astrology!

CANCER (June 21-July 22): Novelist Marcel Proust was a sensitive, dreamy, emotional, self-protective, creative Cancerian. That may explain why he wasn't a good soldier. During his service in the French army, he was ranked 73rd in a squad of 74. On the other hand, his majestically intricate seven-volume novel *In Search of Lost Time* is a masterpieceone of the 20th century's most influential literary works. In evaluating his success as a human being, should we emphasize his poor military performance and downplay his literary output? Of course not! Likewise, Cancerian, in the coming weeks I'd like to see you devote vigorous energy to appreciating what you do best and no energy at all to worrying about your inadequacies.

LEO (July 23-Aug. 22): "Fortune resists half-hearted prayers," wrote the poet Ovid more than 2,000 years ago. I will add that Fortune also resists poorly formulated intentions, feeble vows, and sketchy plansespecially now, during an historical turning point when the world is undergoing massive transformations. Luckily, I don't see those lapses being problems for you in the coming weeks, Leo. According to my analysis, you're primed to be clear and precise. Your willpower should be working with lucid grace. You'll have an enhanced ability to assess your assets and make smart plans for how to use them.

VIRGO (Aug. 23-Sept. 22): Last year the Baltimore Museum of Art announced it would acquire works exclusively from women artists in 2020. A male art critic complained, "That's unfair to male artists." Here's my reply: Among major permanent art collections in the U.S. and Europe, the work of women makes up five percent of the total. So what the Baltimore Museum did is a righteous attempt to rectify the existing excess. It's a just and fair way to address an unhealthy imbalance. In accordance with current omens and necessities, Virgo, I encourage you to perform a comparable correction in your personal sphere.

LIBRA (Sept. 23-Oct. 22): In the course of my life, I've met many sharp thinkers with advanced degrees from fine universitieswho are nonetheless stunted in their emotional intelligence. They may quote Shakespeare and discourse on quantum physics and explain the difference between the philosophies of Kant and Hegel, and yet have less skill in understanding the inner workings of human beings or in creating vibrant intimate relationships. Yet most of these folks are not extreme outliers. I've found that virtually all of us are smarter in our heads than we are in our hearts. The good news, Libra, is that our current Global Healing Crisis is an excellent time for you to play catch up. Do what poet Lawrence Ferlinghetti suggests: "Make your mind learn its way around the heart."

SCORPIO (Oct. 23-Nov. 21): Aphorist Aaron Haspel writes, "The less you are contradicted, the stupider you become. The more powerful you become, the less you are contradicted." Let's discuss how this counsel might be useful to you in the coming weeks. First of all, I suspect you will be countered and challenged more than usual, which will offer you rich opportunities to become smarter. Secondly, I believe you will become more powerful as long as you don't try to stop or discourage the influences that contradict you. In other words, you'll grow your personal authority and influence to the degree that you welcome opinions and perspectives that are not identical to yours.

SAGITTARIUS (Nov. 22-Dec. 21): "It's always too early to quit," wrote author Norman Vincent Peale. We should put his words into perspective, though. He preached "the power of positive thinking." He was relentless in his insistence that we can and should transcend discouragement and disappointment. So we should consider the possibility that he was overly enthusiastic in his implication that we should NEVER give up. What do you think, Sagittarius? I'm guessing this will be an important question for you to consider in the coming weeks. It may be time to re-evaluate your previous thoughts on the matter and come up with a fresh perspective. For example, maybe it's right to give up on one project if it enables you to persevere in another.

CAPRICORN (Dec. 22-Jan. 19): The 16-century mystic nun Saint Teresa of Avila was renowned for being overcome with rapture during her spiritual devotions. At times she experienced such profound bliss through her union with God that she levitated off the ground. "Any real ecstasy is a sign you are moving in the right direction," she wrote. I hope that you will be periodically moving in that direction yourself during the coming weeks, Capricorn. Although it may seem odd advice to receive during our Global Healing Crisis, I really believe you should make appointments with euphoria, delight, and enchantment.

AQUARIUS (Jan. 20-Feb. 18): Grammy-winning musician and composer Pharrell Williams has expertise in the creative process. "If someone asks me what inspires me," he testifies, "I always say, 'That which is missing.'" According to my understanding of the astrological omens, you would benefit from making that your motto in the coming weeks. Our Global Healing Crisis is a favorable time to discover what's absent or empty or blank about your life, and then learn all you can from exploring it. I think you'll be glad to be shown what you didn't consciously realize was lost, omitted, or lacking.

PISCES (Feb. 19-March 20): "I am doing my best to not become a museum of myself," declares poet Natalie Diaz. I think she means that she wants to avoid defining herself entirely by her past. She is exploring tricks that will help her keep from relying so much on her old accomplishments that she neglects to keep growing. Her goal is to be free of her history, not to be weighed down and limited by it. These would be worthy goals for you to work on in the coming weeks, Pisces. What would your first step be?

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Free Will Astrology - Week of May 7 | Advice & Fun | Bend - The Source Weekly

Elon Musk and Grimes Named Their Baby X A-12, Which Must Mean SomethingRight? – Esquire

May 6, 2020 | Author: admin

UPDATE 2: A few hours after Grimes provided a detailed explanation for the name of her baby, the father, Elon Musk chimed in to correct a slight error in her tweet. Grimes said the A-12 part of the baby's name, X A-12, came from the precursor to their favorite aircraft, the SR-71. Musk responded to her tweet, offering a correction: "SR-71, but yes," he wrote. To which Grimes responded, "I am recovering from surgery and barely alive so may my typos b forgiven but, damnit. That was meant to be profound."

UPDATE: Grimes has explained the meaning behind her and Elon Musk's baby, name, X A-12. As she wrote on twitter:

Original post below:

As every new parent knows, there is no greater feeling than looking into a newborn child's eyes, and then assigning it a name that reads like the phonetic spelling of the sound a dial up modem makes while connecting to the World Wide Web. Potentially, that is what Grimes and Elon Musk did in the wee hours of the morning when the couple welcomed a new child into the world. While Grimes has opted to let the child choose its gender, Elon Musk is a bit more ... well...

When asked what the child's name is, Musk also dropped this little nugget. The newest Musk heir is named X A-12 Musk. The baby looks like more of an X A-10 than an X A-12, but this is their choice to make as parents. The internet immediately began dunking on the couple, but Grimes and Elon? These are smart people. If you can build a car to space, you deserve a little more credit. One very complex Reddit theory explains that the symbol () could represent Ash, the A-12 could be representative of the Archangel design effort by Lockheed Martin, and the X is a placeholder. Meaning the actual name would be [placeholder] Ash Archangel Musk, which is quite possibly the most Elon Musk x Grimes collaboration that could ever happen.

But there could be any other number of explanations for this baby name. What if perhaps this really was inspired by the noise of a dial up modem connecting to CompuServe circa 1999? What if, in a real Muskian twist, that's not the baby's name, but just its make and model? Perhaps this is a quantum physics equation the child solved while in the womb?

What if this isn't actually the name of their child, and just a public joke they're playing to keep the actual name of their child private? We may never know. Welcome to the world, X A-12. If that is your real name, kindergarten is going to be rough.

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Elon Musk and Grimes Named Their Baby X A-12, Which Must Mean SomethingRight? - Esquire

Wolfram Physics Project Seeks Theory Of Everything; Is It Revelation Or Overstatement? – Hackaday

May 6, 2020 | Author: admin

Stephen Wolfram, inventor of the Wolfram computational language and the Mathematica software, announced that he may have found a path to the holy grail of physics: A fundamental theory of everything. Even with the subjunctive, this is certainly a powerful statement that should be met with some skepticism.

What is considered a fundamental theory of physics? In our current understanding, there are four fundamental forces in nature: the electromagnetic force, the weak force, the strong force, and gravity. Currently, the description of these forces is divided into two parts: General Relativity (GR), describing the nature of gravity that dominates physics on astronomical scales. Quantum Field Theory (QFT) describes the other three forces and explains all of particle physics.

An overview of particle physics by Headbomb [CC-BY-SA 3.0]Up to now, it has not been possible to unify both General Relativity and Quantum Field Theory since they are formulated within different mathematical frameworks. In particular, treating gravity within the formalism of QFT leads to infinite terms that cannot be canceled out within the generally accepted framework of renormalization. The two most popular attempts to deliver a quantum mechanical description of gravity are String Theory and the lesser know Quantum Loop Gravity. The former would be considered a fundamental theory that describes all forces in nature while the latter limits itself to the description of gravity.

Apart from the incompatibility of QFT and GR there are still several unsolved problems in particle physics like the nature of dark matter and dark energy or the origin of neutrino masses. While these phenomena tell us that the current Standard Model of particle physics is incomplete they might still be explainable within the current frameworks of QFT and GR. Of course, a fundamental theory also has to come up with a natural explanation for these outstanding issues.

Stephen Wolfram is best known for his work in computer science but he actually started his career in physics. He received his PhD in theoretical particle physics at the age of 20 and was the youngest person in history to receive the prestigious McArthur grant. However, he soon left physics to pursue his research into cellular automata which lead to the development of the Wolfram code. After founding his company Wolfram Research he continued to develop the Wolfram computational language which is the basis for the Wolfram Mathematica software. On the one hand, it becomes obvious that Wolfram is a very gifted man, on the other hand, people have sometimes criticized him for being an egomaniac as his brand naming convention subtly suggests.

In 2002, Stephen Wolfram published his 1200-page mammoth book A New Kind of Sciencewhere he applied his research on cellular automata to physics. The main thesis of the book is that simple programs, in particular the Rule 110 cellular automaton, can generate very complex systems through repetitive application of a simple rule. It further claims that these systems can describe all of the physical world and that the Universe itself is computational. The book got controversial reviews, while some found that it contains a cornucopia of ideas others criticized it as arrogant and overstated. Among the most famous critics were Ray Kurzweil and Nobel laureate Steven Weinberg. It was the latter who wrote that:

Wolfram [] cant resist trying to apply his experience with digital computer programs to the laws of nature. [] he concludes that the universe itself would then be an automaton, like a giant computer. Its possible, but I cant see any motivation for these speculations, except that this is the sort of system that Wolfram and others have become used to in their work on computers. So might a carpenter, looking at the moon, suppose that it is made of wood.

The Wolfram Physics Project is a continuation of the ideas formulated in A New Kind of Science and was born out of a collaboration with two young physicists who attended Wolframs summer school. The main idea has not changed, i.e. that the Universe in all its complexity can be described through a computer algorithm that works by iteratively applying a simple rule. Wolfram recognizes that cellular automata may have been too simple to produce this kind of complexity instead he now focuses on hypergraphs.

In mathematics, a graph consists of a set of elements that are related in pairs. When the order of the elements is taken into account this is called a directed graph. The most simple example of a (directed) graph can be represented as a diagram and one can then apply a rule to this graph as follows:

The rule states that wherever a relation that matches {x,y} appears, it should be replaced by {{x ,y},{y,z}}, wherez is a new element. Applying this rule to the graph yields:

By applying this rule iteratively one ends up with more and more complicated graphs as shown in the example here. One can also add complexity by allowing self-loops, rules involving copies of the same relation, or rules depending on multiple relations. When allowing relations between more than two elements, this moves from graphs to hypergraphs.

How is this related to physics? Wolfram surmises that the Universe can be represented by an evolving hypergraph where a position in space is defined by a node and time basically corresponds to the progressive updates. This introduces new physical concepts, e.g. that space and time are discrete, rather than continuous. In this model, the quest for a fundamental theory corresponds to finding the right initial condition and underlying rule. Wolfram and his colleagues think they have already identified the right class of rules and constructed models that reproduce some basic principles of general relativity and quantum mechanics.

A fundamental problem of the model is what Wolfram calls computational irreducibility, meaning that to calculate any state of the hypergraph one has to go through all iterations starting from the initial condition. This would make it virtually impossible to run the computation long enough in order to test a model by comparing it to our current physical Universe.

Wolfram thinks that some basic principles, e.g. the dimensionality of space, can be deduced from the rules itself. Wolfram also points out that although the generated model universes can be tested against observations the framework itself is not amenable to experimental falsification. It is generally true that fundamental physics has long decoupled from the scientific method of postulating hypotheses based on experimental observations. String theory has also been criticized for not making any testable predictions. However, String theory historically developed from nuclear physics while Wolfram does not give any motivation for choosing evolving hypergraphs for his framework. However, some physicists are thinking in similar directions like Nobel laureate Gerard tHooft who has recently published a cellular automaton interpretation of quantum mechanics. In addition, Wolframs colleague, Jonathan Gorard, points out that their approach is a generalization of spin networks used in Loop Quantum Gravity.

On his website, Wolfram invites other people to participate in the project although it is somehow vague how this will work. In general, they need people to work out the potential observable predictions of their model and the relation to other fundamental theories. If you want to dive into the topic in depth there is a 448-page technical introduction on the website and they have also recently started a series of livestreams where they plan to release 400 hours of video material.

Wolframs model certainly contains many valuable ideas and cannot be simply disregarded as crackpottery. Still, most mainstream physicists will probably be skeptical about the general idea of a discrete computational Universe. The fact that Wolfram tends to overstate his findings and publishes through his own media channels instead of going through peer-reviewed physics journals does not earn him any extra credibility.

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Wolfram Physics Project Seeks Theory Of Everything; Is It Revelation Or Overstatement? - Hackaday

Archer to work alongside IBM in progressing quantum computing – ZDNet

May 6, 2020 | Author: admin

Archer CEO Dr Mohammad Choucair and quantum technology manager Dr. Martin Fuechsle

Archer Materials has announced a new agreement with IBM which it hopes will advance quantum computing and progress work towards solutions for the greater adoption of the technology.

Joining the IBM Q Network, Archer will gain access to IBM's quantum computing expertise and resources, seeing the Sydney-based company use IBM's open-source software framework, Qiskit.

See also: Australia's ambitious plan to win the quantum race

Archer is the first Australian company that develops a quantum computing processor and hardware to join the IBM Q Network. The IBM Q Network provides access to the company's experts, developer tools, and cloud-based quantum systems through IBM Q Cloud.

"We are the first Australian company building a quantum chip to join into the global IBM Q Network as an ecosystem partner, a group of the very best organisations at the forefront of quantum computing." Archer CEO Dr Mohammad Choucair said.

"Ultimately, we want Australian businesses and consumers to be one of the first beneficiaries of this exciting technology, and now that we are collaborating with IBM, it greatly increases our chances of success".

Archer is advancing the commercial readiness of its12CQ qubit processor chip technology towards a minimum viable product.

"We look forward to working with IBM and members of the network to address the most fundamental challenges to the wide-scale adoption of quantum computing, using our potentially complementary technologies as starting points," Choucair added.

In November, Archer said it was continuing to inch towards its goal of creating a room temperature quantum computer, announcing at the time it had assembled a three qubit array.

The company said it has placed three isolated qubits on a silicon wafer with metallic control electrodes being used for measurement. Archer has previously told ZDNet it conducts measurements by doing magnetic fields sweeps at microwave frequencies.

"The arrangement of the qubits was repeatable and reproducible, thereby allowing Archer to quickly build and test working prototypes of quantum information processing devices incorporating a number of qubits; individual qubits; or a combination of both, which is necessary to meet Archer's aim of building a chip for a practical quantum computer," the company said.

In August, the company said it hadassembled its first room-temperature quantum bit.

Archer is building chip prototypes at the Research and Prototype Foundry out of the University of Sydney's AU$150 million Sydney Nanoscience Hub.

2020s are the decade of commercial quantum computing, says IBM

IBM spent a great deal of time showing off its quantum-computing achievements at CES, but the technology is still in its very early stages.

What is quantum computing? Understanding the how, why and when of quantum computers

There are working machines today that perform some small part of what a full quantum computer may eventually do. But what are the real-world applications for quantum computing?

Quantum computing has arrived, but we still don't really know what to do with it

Even for a technology that makes a virtue of uncertainty, where quantum goes next is something of a mystery.

Quantum computing: Myths v. Realities (TechRepublic)

Futurist Isaac Arthur explains why quantum computing is a lot more complicated than classical computing.

Link:
Archer to work alongside IBM in progressing quantum computing - ZDNet

Physicists Criticize Stephen Wolfram’s ‘Theory of Everything’ – Scientific American

May 6, 2020 | Author: admin

Stephen Wolfram blames himself for not changing the face of physics sooner.

I do fault myself for not having done this 20 years ago, the physicist turned software entrepreneur says. To be fair, I also fault some people in the physics community for trying to prevent it happening 20 years ago. They were successful. Back in 2002, after years of labor, Wolfram self-published A New Kind of Science, a 1,200-page magnum opus detailing the general idea that nature runs on ultrasimple computational rules. The book was an instant best seller and received glowing reviews: the New York Times called it a first-class intellectual thrill. But Wolframs arguments found few converts among scientists. Their work carried on, and he went back to running his software company Wolfram Research. And that is where things remaineduntil last month, when, accompanied by breathless press coverage (and a 448-page preprint paper), Wolfram announced a possible path to the fundamental theory of physics based on his unconventional ideas. Once again, physicists are unconvincedin no small part, they say, because existing theories do a better job than his model.

At its heart, Wolframs new approach is a computational picture of the cosmosone where the fundamental rules that the universe obeys resemble lines of computer code. This code acts on a graph, a network of points with connections between them, that grows and changes as the digital logic of the code clicks forward, one step at a time. According to Wolfram, this graph is the fundamental stuff of the universe. From the humble beginning of a small graph and a short set of rules, fabulously complex structures can rapidly appear. Even when the underlying rules for a system are extremely simple, the behavior of the system as a whole can be essentially arbitrarily rich and complex, he wrote in a blog post summarizing the idea. And this got me thinking: Could the universe work this way? Wolfram and his collaborator Jonathan Gorard, a physics Ph.D. candidate at the University of Cambridge and a consultant at Wolfram Research, found that this kind of model could reproduce some of the aspects of quantum theory and Einsteins general theory of relativity, the two fundamental pillars of modern physics.

But Wolframs models ability to incorporate currently accepted physics is not necessarily that impressive. Its this sort of infinitely flexible philosophy where, regardless of what anyone said was true about physics, they could then assert, Oh, yeah, you could graft something like that onto our model, says Scott Aaronson, a quantum computer scientist at the University of Texas at Austin.

When asked about such criticisms, Gorard agreesto a point. Were just kind of fitting things, he says. But we're only doing that so we can actually go and do a systematized search for specific rules that fit those of our universe.

Wolfram and Gorard have not yet found any computational rules meeting those requirements, however. And without those rules, they cannot make any definite, concrete new predictions that could be experimentally tested. Indeed, according to critics, Wolframs model has yet to even reproduce the most basic quantitative predictions of conventional physics. The experimental predictions of [quantum physics and general relativity] have been confirmed to many decimal placesin some cases, to a precision of one part in [10 billion], says Daniel Harlow, a physicist at the Massachusetts Institute of Technology. So far I see no indication that this could be done using the simple kinds of [computational rules] advocated by Wolfram. The successes he claims are, at best, qualitative. Further, even that qualitative success is limited: There are crucial features of modern physics missing from the model. And the parts of physics that it can qualitatively reproduce are mostly there because Wolfram and his colleagues put them in to begin with. This arrangement is akin to announcing, If we suppose that a rabbit was coming out of the hat, then remarkably, this rabbit would be coming out of the hat, Aaronson says. And then [going] on and on about how remarkable it is.

Unsurprisingly, Wolfram disagrees. He claims that his model has replicated most of fundamental physics already. From an extremely simple model, were able to reproduce special relativity, general relativity and the core results of quantum mechanics, he says, which, of course, are what have led to so many precise quantitative predictions of physics over the past century.

Even Wolframs critics acknowledge he is right about at least one thing: it is genuinely interesting that simple computational rules can lead to such complex phenomena. But, they hasten to add, that is hardly an original discovery. The idea goes back long before Wolfram, Harlow says. He cites the work of computing pioneers Alan Turing in the 1930s and John von Neumann in the 1950s, as well as that of mathematician John Conway in the early 1970s. (Conway, a professor at Princeton University, died of COVID-19 last month.) To the contrary, Wolfram insists that he was the first to discover that virtually boundless complexity could arise from simple rules in the 1980s. John von Neumann, he absolutely didnt see this, Wolfram says. John Conway, same thing.

Born in London in 1959, Wolfram was a child prodigy who studied at Eton College and the University of Oxford before earning a Ph.D. in theoretical physics at the California Institute of Technology in 1979at the age of 20. After his Ph.D., Caltech promptly hired Wolfram to work alongside his mentors, including physicist Richard Feynman. I dont know of any others in this field that have the wide range of understanding of Dr. Wolfram, Feynman wrote in a letter recommending him for the first ever round of MacArthur genius grants in 1981. He seems to have worked on everything and has some original or careful judgement on any topic. Wolfram won the grantat age 21, making him among the youngest ever to receive the awardand became a faculty member at Caltech and then a long-term member at the Institute for Advanced Study in Princeton, N.J. While at the latter, he became interested in simple computational systems and then moved to the University of Illinois in 1986 to start a research center to study the emergence of complex phenomena. In 1987 he founded Wolfram Research, and shortly after he left academia altogether. The software companys flagship product, Mathematica, is a powerful and impressive piece of mathematics software that has sold millions of copies and is today nearly ubiquitous in physics and mathematics departments worldwide.

Then, in the 1990s, Wolfram decided to go back to scientific researchbut without the support and input provided by a traditional research environment. By his own account, he sequestered himself for about a decade, putting together what would eventually become A New Kind of Science with the assistance of a small army of his employees.

Upon the release of the book, the media was ensorcelled by the romantic image of the heroic outsider returning from the wilderness to single-handedly change all of science. Wired dubbed Wolfram the man who cracked the code to everything on its cover. Wolfram has earned some bragging rights, the New York Times proclaimed. No one has contributed more seminally to this new way of thinking about the world. Yet then, as now, researchers largely ignored and derided his work. Theres a tradition of scientists approaching senility to come up with grand, improbable theories, the late physicist Freeman Dyson told Newsweek back in 2002. Wolfram is unusual in that hes doing this in his 40s.

Wolframs story is exactly the sort that many people want to hear, because it matches the familiar beats of dramatic tales from science history that they already know: the lone genius (usually white and male), laboring in obscurity and rejected by the establishment, emerges from isolation, triumphantly grasping a piece of the Truth. But that is rarelyif everhow scientific discovery actually unfolds. There are examples from the history of science that superficially fit this image: Think of Albert Einstein toiling away on relativity as an obscure Swiss patent clerk at the turn of the 20th century. Or, for a more recent example, consider mathematician Andrew Wiles working in his attic for years to prove Fermats last theorem before finally announcing his success in 1995. But portraying those discoveries as the work of a solo genius, romantic as it is, belies the real working process of science. Science is a group effort. Einstein was in close contact with researchers of his day, and Wiless work followed a path laid out by other mathematicians just a few years before he got started. Both of them were active, regular participants in the wider scientific community. And even so, they remain exceptions to the rule. Most major scientific breakthroughs are far more collaborativequantum physics, for example, was developed slowly over a quarter-century by dozens of physicists around the world.

I think the popular notion that physicists are all in search of the eureka moment in which they will discover the theory of everything is an unfortunate one, says Katie Mack, a cosmologist at North Carolina State University. We do want to find better, more complete theories. But the way we go about that is to test and refine our models, look for inconsistencies and incrementally work our way toward better, more complete models.

Most scientists would readily tell you that their discipline isand always has beena collaborative, communal process. Nobody can revolutionize a scientific field without first getting the critical appraisal and eventual validation of their peers. Today this requirement is performed through peer reviewa process Wolframs critics say he has circumvented with his announcement. Certainly theres no reason that Wolfram and his colleagues should be able to bypass formal peer review, Mack says. And they definitely have a much better chance of getting useful feedback from the physics community if they publish their results in a format we actually have the tools to deal with.

Mack is not alone in her concerns. Its hard to expect physicists to comb through hundreds of pages of a new theory out of the blue, with no buildup in the form of papers, seminars and conference presentations, says Sean Carroll, a physicist at Caltech. Personally, I feel it would be more effective to write short papers addressing specific problems with this kind of approach rather than proclaiming a breakthrough without much vetting.

So why did Wolfram announce his ideas this way? Why not go the traditional route? I don't really believe in anonymous peer review, he says. I think its corrupt. Its all a giant story of somewhat corrupt gaming, I would say. I think its sort of inevitable that happens with these very large systems. Its a pity.

So what are Wolframs goals? He says he wants the attention and feedback of the physics community. But his unconventional approachsoliciting public comments on an exceedingly long paperalmost ensures it shall remain obscure. Wolfram says he wants physicists respect. The ones consulted for this story said gaining it would require him to recognize and engage with the prior work of others in the scientific community.

And when provided with some of the responses from other physicists regarding his work, Wolfram is singularly unenthused. Im disappointed by the naivete of the questions that youre communicating, he grumbles. I deserve better.

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Physicists Criticize Stephen Wolfram's 'Theory of Everything' - Scientific American

A Discovery That Long Eluded Physicists: Superconductivity to the Edge – SciTechDaily

May 6, 2020 | Author: admin

Researchers at Princeton have discovered superconducting currents traveling along the outer edges of a superconductor with topological properties, suggesting a route to topological superconductivity that could be useful in future quantum computers. The superconductivity is represented by the black center of the diagram indicating no resistance to the current flow. The jagged pattern indicates the oscillation of the superconductivity which varies with the strength of an applied magnetic field. Credit: Stephan Kim, Princeton University

Princeton researchers detect a supercurrent a current flowing without energy loss at the edge of a superconductor with a topological twist.

A discovery that long eluded physicists has been detected in a laboratory at Princeton. A team of physicists detected superconducting currents the flow of electrons without wasting energy along the exterior edge of a superconducting material. The finding was published May 1 in the journal Science.

The superconductor that the researchers studied is also a topological semi-metal, a material that comes with its own unusual electronic properties. The finding suggests ways to unlock a new era of topological superconductivity that could have value for quantum computing.

To our knowledge, this is the first observation of an edge supercurrent in any superconductor, said Nai Phuan Ong, Princetons Eugene Higgins Professor of Physics and the senior author on the study.

Our motivating question was, what happens when the interior of the material is not an insulator but a superconductor? Ong said. What novel features arise when superconductivity occurs in a topological material?

Although conventional superconductors already enjoy widespread usage in magnetic resonance imaging (MRI) and long-distance transmission lines, new types of superconductivity could unleash the ability to move beyond the limitations of our familiar technologies.

Researchers at Princeton and elsewhere have been exploring the connections between superconductivity and topological insulators materials whose non-conformist electronic behaviors were the subject of the 2016 Nobel Prize in Physics for F. Duncan Haldane, Princetons Sherman Fairchild University Professor of Physics.

Topological insulators are crystals that have an insulating interior and a conducting surface, like a brownie wrapped in tin foil. In conducting materials, electrons can hop from atom to atom, allowing electric current to flow. Insulators are materials in which the electrons are stuck and cannot move. Yet curiously, topological insulators allow the movement of electrons on their surface but not in their interior.

To explore superconductivity in topological materials, the researchers turned to a crystalline material called molybdenum ditelluride, which has topological properties and is also a superconductor once the temperature dips below a frigid 100 milliKelvin, which is -459 degrees Fahrenheit.

Most of the experiments done so far have involved trying to inject superconductivity into topological materials by putting the one material in close proximity to the other, said Stephan Kim, a graduate student in electrical engineering, who conducted many of the experiments. What is different about our measurement is we did not inject superconductivity and yet we were able to show the signatures of edge states.

The team first grew crystals in the laboratory and then cooled them down to a temperature where superconductivity occurs. They then applied a weak magnetic field while measuring the current flow through the crystal. They observed that a quantity called the critical current displays oscillations, which appear as a saw-tooth pattern, as the magnetic field is increased.

Both the height of the oscillations and the frequency of the oscillations fit with predictions of how these fluctuations arise from the quantum behavior of electrons confined to the edges of the materials.

When we finished the data analysis for the first sample, I looked at my computer screen and could not believe my eyes, the oscillations we observed were just so beautiful and yet so mysterious, said Wudi Wang, who as first author led the study and earned his Ph.D. in physics from Princeton in 2019. Its like a puzzle that started to reveal itself and is waiting to be solved. Later, as we collected more data from different samples, I was surprisedat how perfectly the data fit together.

Researchers have long known that superconductivity arises when electrons, which normally move about randomly, bind into twos to form Cooper pairs, which in a sense dance to the same beat. A rough analogy is a billion couples executing the same tightly scripted dance choreography, Ong said.

The script the electrons are following is called the superconductors wave function, which may be regarded roughly as a ribbon stretched along the length of the superconducting wire, Ong said. A slight twist of the wave function compels all Cooper pairs in a long wire to move with the same velocity as a superfluid in other words acting like a single collection rather than like individual particles that flows without producing heating.

If there are no twists along the ribbon, Ong said, the Cooper pairs are stationary and no current flows. If the researchers expose the superconductor to a weak magnetic field, this adds an additional contribution to the twisting that the researchers call the magnetic flux, which, for very small particles such as electrons, follows the rules of quantum mechanics.

The researchers anticipated that these two contributors to the number of twists, the superfluid velocity and the magnetic flux, work together to maintain the number of twists as an exact integer, a whole number such as 2, 3 or 4 rather than a 3.2 or a 3.7. They predicted that as the magnetic flux increases smoothly, the superfluid velocity would increase in a saw-tooth pattern as the superfluid velocity adjusts to cancel the extra .2 or add .3 to get an exact number of twists.

The team measured the superfluid current as they varied the magnetic flux and found that indeed the saw-tooth pattern was visible.

In molybdenum ditelluride and other so-called Weyl semimetals, this Cooper-pairing of electrons in the bulk appears to induce a similar pairing on the edges.

The researchers noted that the reason why the edge supercurrent remains independent of the bulk supercurrent is currently not well understood. Ong compared the electrons moving collectively, also called condensates, to puddles of liquid.

From classical expectations, one would expect two fluid puddles that are in direct contact to merge into one, Ong said. Yet the experiment shows that the edge condensates remain distinct from that in the bulk of the crystal.

The research team speculates that the mechanism that keeps the two condensates from mixing is the topological protection inherited from the protected edge states in molybdenum ditelluride. The group hopes to apply the same experimental technique to search for edge supercurrents in other unconventional superconductors.

There are probably scores of them out there, Ong said.

Reference: Evidence for an edge supercurrent in the Weyl superconductor MoTe2 by Wudi Wang, Stephan Kim, Minhao Liu, F. A. Cevallos, Robert. J. Cava and Nai Phuan Ong, 1 May 2020, Science.DOI: 10.1126/science.aaw9270

Funding: The research was supported by the U.S. Army Research Office (W911NF-16-1-0116). The dilution refrigerator experiments were supported by the U.S. Department of Energy (DE- SC0017863). N.P.O. and R.J.C. acknowledge support from the Gordon and Betty Moore Foundations Emergent Phenomena in Quantum Systems Initiative through grants GBMF4539 (N.P.O.) and GBMF-4412 (R.J.C.). The growth and characterization of crystals were performed by F.A.C. and R.J.C., with support from the National Science Foundation (NSF MRSEC grant DMR 1420541).

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A Discovery That Long Eluded Physicists: Superconductivity to the Edge - SciTechDaily

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Physicists Criticize Stephen Wolfram’s ‘Theory of Everything’ – Scientific American

A Discovery That Long Eluded Physicists: Superconductivity to the Edge – SciTechDaily

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