#14. 5 pages. As foreign-funded enterprises export over 50 percent of China's total exports, such energy efficiency improvements will affect the coefficient of exports on the sub-sector energy intensity. D. in 2007 from Tsinghua University and did postdoctoral research at Stanford University and the University of California, Santa Barbara, before joining the Stanford faculty. Take the survey ... Xiaoliang Qi (Stanford U., Phys. © Stanford University, Stanford, California 94305. and ; Nordita), Masao Ninomiya . This means that the operator X4 evolves into a more complicated operator that flips more qubits. Suh, “Entanglement tsunami: Universal scaling in holographic thermalization,”. The key idea behind the researchers’ work is that introducing randomness may simplify the problem. Attendee List Download Talk Schedule Videos. Researchers uncover the mechanism that makes some oil droplets change shape from spheres to icosahedrons to flattened plates. A recently proposed explanation invokes quantum “information scrambling” [1, 3], in which information gets rapidly dispersed into quantum correlations among the particles of a system. [6]). It is natural to ask whether a counterpart of chaos exists in the quantum world. By removing the memory of previous rounds, the game gets easier, as players don’t have to remember what happened in past rounds. We present evidence that the answer is "yes" for generic local Hamiltonians, given either the ground state or an excited eigenstate. Read More », A microcavity-based source of photon pairs achieves one hundred times the efficiency of state-of-the-art devices. Here we prove a result about quantum channels indicating that an aspect of this phenomenon is completely general. "We are kind of in the early exploration of the science at this moment," Lai said. Request full-text PDF. The duo compares the results of their random-Hamiltonian approach with those obtained for a specific Hamiltonian (without randomness), which can only be computed numerically. Xiao-Liang Qi (Stanford U., Phys. His current research focuses on the relations between quantum entanglement, quantum chaos, and quantum gravity. Theoretical Physics. In daily life, “chaos” describes anything messy. (Oct 3, 2018) Published in: Nature Phys. Following in the tradition of Albert Einstein, Niels Bohr, and Richard Feynman, the goals of SITP are to uncover the basic physical principles governing the world of natural phenomena. Dept.) Winner of the Standing Ovation Award for “Best PowerPoint Templates” from Presentations Magazine. Associate Professor of Physics and of Photon Science Leonardo Senatore. 28.29; Johns Hopkins University ; Show all 8 authors Hide. Xiao-Liang Qi, Daniel Ranard We ask whether the knowledge of a single eigenstate of a local Hamiltonian is sufficient to uniquely determine the Hamiltonian. They'll give your presentations a professional, memorable appearance - the kind of sophisticated look that today's audiences expect. Learn more. 6 (2010) 284; e-Print: 0908.1537 [cond-mat.other] DOI: 10.1038/nphys1534; View in: ADS Abstract Service; pdf cite. Even determining how much the size of an operator changes after a short time can be difficult, because information from the past can have a complex effect on the future. Xu and Swingle show that this formalism enables a quantitative description of how chaos spreads in a many-body system. Only theory has explored the bizarre behaviors this communication would cause. There is considerable cross-fertilization in some of these endeavors with faculty in the SLAC Theory Group and the Kavli Institute for Particle An analogous family of model with discrete time steps, named as random circuits, have been studied in literature (see Ref. Douglas Stanford Associate Professor Theoretical Astrophysics and Cosmology. In addition, by their mere presence in the domestic markets, foreign technologies can inspire and stimulate local enterprises to develop new energy efficient technologies. 2). Their support will thus be defined by a smooth distribution—like the smooth front of a water wave—and chaotic dynamics may further reshape the wave front. Winner of the Standing Ovation Award for “Best PowerPoint Templates” from Presentations Magazine. 4 citations. This scrambling is a memory-loss mechanism that can cause the unpredictability of chaos. The researchers adapt BCC models to provide a description of chaotic information scrambling. Special operators, like a single-spin flipping operator, have a sharply defined “support”—the set of qubits on which they act. 1). With further approximations, they tackle the case of small N, which is analytically harder, finding similar wave propagation and dissipation features. Holger Bech Nielsen Bohr Inst. This research is published in Physical Review X. Xiaoliang Qi is a professor of physics at Stanford University. At such small distances, electrons on the top and bottom of the nanoribbons can cross-talk, according to predictions by coauthors and SIMES researchers Zhang and Xiaoliang Qi. Starting with infinitely large N—to simplify the analysis—they determine that the wave front moves as a solitary wave without changing shape. Topological insulators materialize a topological quantum state of matter where unusual gapless metallic state protected by time-reversal symmetry appears at the edge or surface. Now, Shenglong Xu and Brian Swingle of the University of Maryland, College Park, have taken a step toward this description by studying chaos with models based on a quantum version of Brownian motion [4]. Sign up to receive weekly email alerts from Physics. By helping us model quantum chaos, the new operator scrambling approach may contribute to unlocking the mystery of quantum gravity. Such studies have hinted at some characteristic features of quantum chaos. Loosely speaking, this is like shuffling cards after each round in a card game. He received his Ph. Xiaoliang Qi Professor Email: xlqi@stanford.edu. The two states are related by a simple operator X4 that flips the fourth bit. A model based on Brownian motion describes the tsunami-like propagation of chaotic behavior in a system of quantum particles. D. in 2007 from Tsinghua University and did postdoctoral research at Stanford University and the University of California, Santa Barbara, before joining the Stanford faculty. Dept.) https://profiles.stanford.edu/xiaoliang-qi, Ideas from superresolution imaging inspire a way to measure time intervals with unprecedented precision—an ability that could enhance our understanding of ultrafast processes. The details of the wave front, such as its speed and shape, can reveal important information about the underlying linear or nonlinear effects that govern the propagation of the wave. Nature Phys. If the system evolves in time, the states may become very different, such that they can only be related by flipping many qubits. Xiaoliang Qi. Developing a theory that fully describes information scrambling remains, however, a daunting task. In recent years, progress in holographic duality [9] led to the idea that gravity might be an emergent phenomenon arising from many-body interactions in a quantum chaotic system. Dept. Dept.) Learn more. Initially, the quake only creates local waves, but its effect can result in a large-scale tsunami, whose propagation is described by a nonlinear equation [7]. At such small distances, electrons on the top and bottom of the nanoribbons can cross-talk, according to predictions by coauthors and SIMES researchers Zhang and Xiaoliang Qi. Professor of Applied Physics and of Physics, Emeritus, Associate Professor of Applied Physics and , by courtesy, of Neurobiology and of Electrical Engineering, Stanford Professor of Quantum Physics and Professor, by courtesy, of Computer Science, Professor of Physics and Director, Stanford Institute for Theoretical Physics, Professor of Physics and, by courtesy, of Mathematics, Assistant Professor of Physics and, by courtesy, of Applied Physics, Anne T. and Robert M. Bass Professor in the School of Humanities and Sciences, Associate Professor of Physics and of Photon Science, Associate Professor of Physics and of Particle Physics and Astrophysics, Richard Herschel Weiland Professor in the School of Humanities and Sciences, Stanford Institute for Theoretical Physics, Kavli Institute for Particle Astrophysics and Cosmology (KIPAC), Geballe Laboratory for Advanced Materials (GLAM). In physics, the term has a more specific meaning: It refers to systems that, while subject to deterministic laws, are totally unpredictable because of an exponential sensitivity to initial conditions—think of the butterfly flapping its wings and causing a distant tornado. However, as the operators evolve in time, they may turn into linear superpositions of several operators acting on different qubits. World's Best PowerPoint Templates - CrystalGraphics offers more PowerPoint templates than anyone else in the world, with over 4 million to choose from. The future positions and momenta are deterministically related to the initial conditions, but this connection grows more mathematically complex with time. Eva Silverstein Professor Email: evas@stanford.edu. World's Best PowerPoint Templates - CrystalGraphics offers more PowerPoint templates than anyone else in the world, with over 4 million to choose from. In their mathematical derivation, this memory erasure simplifies the dynamics of the system, such that the spreading of chaos can then be characterized by a single differential equation. It from Qubit, the Simons Collaboration on Quantum Fields, Gravity, and Information, will host a workshop December 5-7 at the Simons Center for Geometry and Physics. Xiaoliang Qi (Stanford U., Phys. Due to the lack of comprehensive reviews in this emerging field, this review may catch great interest and inspire many new opportunities across a broad range of disciplines. Over the past few decades we have witnessed a rapid exchange and infuse of ideas across different fields: from entanglement in quantum information to quantum phase transitions and topological order in many-body systems, and also to the holographic principle in the gravity-field theory (AdS/CFT) duality. They'll give your presentations a professional, memorable appearance - the kind of sophisticated look that today's audiences expect. The comparison shows qualitative agreement between the two cases, supporting the validity of the BCC approach. Learn more. Theoretical Astrophysics and Cosmology Theoretical Physics. Use of the American Physical Society websites and journals implies that the user has read and agrees to our Terms and Conditions and any applicable Subscription Agreement. In four dimensions Weyl fermions possess a chiral anomaly which leads to several special features in the transport phenomena, such as the negative longitudinal magnetoresistivity. The advantages of such an approach are known from thermodynamics: While it is impossible to describe the exact state of gas molecules in a room, one can predict the relation between the gas pressure and temperature with high accuracy by assuming a random distribution of the particles’ states. Read More », For an important quantum many-body problem, a hybrid quantum-classical algorithm could outperform purely classical approaches using surprisingly few quantum resources. Xiaoliang Qi (Stanford) “Eternal traversable wormhole” Seminar Organizer July 31, 2018. Stanford group Xiaoliang Qi, Andrei Bernevig, Congjun Wu, Chaoxing Liu, Taylor Hughes, Sri Raghu, Suk-bum ChungStanford experimentalists Yulin Chen, Ian Fisher, ZX Shen, Yi Cui, Aharon Kapitulnik, Goldhaber-Gordon Wuerzburg colleagues Laurens Molenkamp, Hartmut Buhmann, Markus Koenig, Ewelina Hankiewicz, Bjoern TrauzettleTsinghua colleagues Qikun Xue, Jinfeng Jia, Xi Chen, Bangfen … World's Best PowerPoint Templates - CrystalGraphics offers more PowerPoint templates than anyone else in the world, with over 4 million to choose from. Professor of Physics Douglas Stanford. ArXiv papers. Recent work has explored how this “operator scrambling” is related to quantum chaos [5, 6]. Leonard Susskind is the Felix Bloch professor of Theoretical physics at Stanford University. Comptes Rendus Physique 14 (2013) 857-870 • e-Print: 1309.4464 • DOI: 10.1016/j.crhy.2013.10.010 [3] ADLER-BELL-JACKIW ANOMALY AND WEYL FERMIONS IN CRYSTAL. In quantum mechanics, physical observables like position and momentum become operators, which cannot be simultaneously determined with arbitrary accuracy because of the Heisenberg uncertainty principle. Extending the approach to operator scrambling, however, is generally hard. Sciences is established to inspire Asia's most promising young Ph_D_ students to become future leaders in life sciences_ ChÌnese BÌobgÌca0 Investögators SocÌety Bdennbao Conference The Ray wu Awards and the CBIS Young Investigator Awards August 2016 Chengdue Chlna . Event Details. In classical physics, a familiar example of chaos is the three-body problem: When two planets orbit a star, the motion of the system is extremely sensitive to the bodies’ initial positions and momenta. D. A. Roberts, D. Stanford, and L. Susskind, “Localized shocks,”, Physical Review Physics Education Research, https://profiles.stanford.edu/xiaoliang-qi, Locality, Quantum Fluctuations, and Scrambling, Ultrabright Photons for Single-Chip Quantum Devices, Gaining a Quantum Advantage Sooner than Expected, An Octad for Darmstadtium and Excitement for Copernicium, Psychedelic View of Fluid in Porous Materials, Stanford Institute for Theoretical Physics, Stanford University, Stanford, CA 94305, USA. He received his Ph. We show that for any evolution of the system and … Xiaoliang Qi. A major goal of Xu and Swingle’s work is to provide a quantitative description of such dynamics. Such models characterize chaos in terms of quantum-mechanical operators that grow more complex over time. This infinite- N limit is unstable, however, and for any finite N, they find a wave front that becomes smoother and smoother as time goes on. We released the new INSPIRE API Learn more. Email ... Publications on INSPIRE. Xiaoliang Qi is a professor of physics at Stanford University. Associate Professor of Physics and of Particle Physics and Astrophysics Stephen Shenker. Organized by: Matthew Headrick, Alex Maloney, and Mark Van Raamsdonk. Welcome to the new INSPIRE! Video from a new technique reveals the chaotic motion of a fluid flowing through a pile of gravel. Studying operator scrambling is a difficult task, because chaotic systems are hard to tackle analytically and numerically. Citations per year. Theoretical Physics. Recent developments in transport phenomena in Weyl semimetals Pavan Hosur, Xiaoliang Qi The last decade has witnessed great advancements in the science and engineering of systems with unconventional band structures, seeded by studies of graphene and topological insulators. Aug 12, 2009. 2010 2013 2016 2019 2020 0 5 10 15. Dept.) . This first quantum revolution enabled the amazing technological developments of the … 14 (2018) 10, 984-987; DOI cite. Chang-Yu Hou , Claudio Chamon , Christopher Mudry (PSI, Villigen) Phys.Rev.Lett. Date: October 23, 2018 3:40 pm – 4:40 pm; Categories: String Seminar; We construct a nearly-AdS2 solution describing an eternal traversable wormhole. In a system of qubits, such as an ensemble of electron spins in a crystal, flipping a single qubit (or a few qubits) in a chaotic system is like triggering a localized earthquake in the middle of the ocean. These topological … cond-mat. There are many reasons why a more quantitative and systematic understanding of quantum chaos will be important. Presented By: Definition The Hall effect is the production of a voltage difference (the Hall voltage) across a current carrying conductor (in presence of magnetic ... – A free PowerPoint PPT presentation (displayed as a Flash slide show) on PowerShow.com - id: 441f02-NDBiN ... Xiaoliang Qi (Stanford U., Phys. Take the survey. Richard Herschel Weiland Professor in the School of Humanities and Sciences Eva Silverstein . Read More », The discovery that copernicium can decay into a new isotope of darmstadtium and the observation of a previously unseen excited state of copernicium provide clues to the location of the “island of stability.”. Published in: Nature Phys. Similar behavior is expected in the dynamics of quantum operators (Fig. Download PDF Abstract: In this paper we propose a space-time random tensor network approach for understanding holographic duality. Authors: Xiao-Liang Qi, Taylor Hughes, Shou-Cheng Zhang. Consider, for example, two states of a system of N qubits that only differ in the state of one bit (Fig. These models are based on a quantum version of the Brownian-motion models describing the erratic movement of molecules in a fluid. To icosahedrons to flattened plates have a sharply defined “ support ” —the set of qubits on they. 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