完善资料让更多小伙伴认识你,还能领取20积分哦, 立即完善>
当今世界量子力学理论与实践相结合前沿探索探讨多则Advanced Quantum Theory Development and Application in the Modern World 现代世界的高级量子理论发展与应用 2020-07-22 1. Dynamic correlation functions of 1d quantum liquids Talk about recent progress in understanding dynamic properties of 1d liquids, which goes beyond Luttinger approximation of linearized dispersion relation. I shall cover both fermionic and bosonic liquids and mention relations to a number of exactly solvable models. ***********************************(Total No. 87) 2. Algorithmic Aspects of Secure Computation (Part 1,2) We survey some recent progress in the design of efficient protocols for secure computation and communication, in a variety of cryptographic settings. The common thread is the usefulness of interesting algorithmic methods originally developed for non-cryptographic applications. This is an expanded version of the first half of an invited talk given at ISAAC 2010. ********************************** 3.On the Computation of Weil Pairing and Tate Pairing Over the past decade, we have seen several remarkable applications of Weil/Tate pairings in cryptography. For example, they are used for the reduction of discrete logarithm problem for certain class of elliptic curves. They are also basic building blocks for some exciting new cryptographic primitives. In this talk,start by formulating computational procedure that relates a special class of divisors and rational functions. Then discuss the Weil/Tate pairings on elliptic curves, and the Miller's algorithm for computing pairings. In the last part, discuss our refinements of Miller's algorithm and some implementation issues. ********************************** 4.Superradiance, Photon phase diffusion, Berry phase and number squeezed state of cold atoms or superconducting qubits inside a cavity Recently, strong coupling regimes of BEC atoms inside an optical cavity and superconducting qubits, quantum dots, electron spins inside a micro-wave circuit cavity were achieved experimentally. The strong coupling regimes in all these systems can be described by the Dicke model. Here study the cavity transmission and Fluorescence spectra by solving the Dicke model by $ 1/ N $ expansion. In the normal state, find a $ sqrt{N} $ behavior of the collective Rabi splitting consistent with the experimental data. Inside the superradiant phase, identify a high frequency mode and also an emergent quantum phase diffusion mode with a corresponding Berry phase at a finite $ N $ and determine their corresponding spectral weights. Also work out many remarkable experimental consequences of this quantum phase mode such as its low frequency, high spectral weight, consecutive photons plateaus, photon number squeezing properties and photon statistics. Argue that recent experimental advances in both cold atoms and semiconductor systems should motivate a new emerging interdisciplinary field of quantum optics and quantum phases which can be dubbed as " Strongly correlated quantum optics". *********************************** 5. Tensor product state approach to the strongly correlated quantum systems The spin 1/2 J1-J2 Antiferromagnetic Heisenberg model on square lattice has raised great attention for its intriguing quantum phase transition and possible exotic phases. Due to its frustrated nature, a large scale low temperature quantum Monte Carlo study is prohibited. A tensor network variational wavefunction ansatz, on the other hand, suites very well to describe the strongly correlated quantum many body systems, and the tensor network method is free of the negative sign problem due to its variational nature. Thus explore the ground state phase diagram of this model via a tensor network approach. Using a recently proposed cluster update algorithm for tensor network states, be able to access the tensor network ground state with a virtual bond dimension D up to 9. Observed a second order quantum phase transition from an antiferromagnetic ordered phase to a paramagnetic disordered phase at a critical point J2_c = 0.47. The paramagnetic disordered phase preserves all symmetries of the Hamiltonian and does not have any local order. A spin liquid nature of this disordered paramagnetic state is very likely. Further studied the topological entanglement entropy of the disordered paramagnetic phase and discovered that it belongs to the Z2 topological class. ************************************ 6. Eigenfunctions on a Riemannian manifold and representations of a vertex operator algebra Conjectures by physicists on nonlinear sigma models are one of the most influential sources of inspirations and motivations for many works in geometry in the past two or three decades. Unfortunately nonlinear sigma models are still not mathematically constructed. In the talk, discuss the first step in a program to construct these models mathematically using Riemannian geometry and the representation theory of vertex operator algebras. Given a Riemannian manifold M, for an open ball centered at a point on M with radius less than or equal to the injectivity radius at the point, using normal coordinates at points in the oepn ball, construct a module for a Heisenberg algebra generated by the space of smooth functions such that on smooth functions, L(0) acts as the Laplacian . Using these modules, modules for certain subalgebras of the Heisenberg algebras and the gluing method, construct a sheaf of weak modules for a sheaf of vertex operator algebras generated by the sheaf of smooth functions. In particular, construct an L(0)-semisimple lower-bounded generalized module for the vertex operator algebra of global sections on M generated by an eigenfunction of the Laplacian on M. ************************************ 7. Levin-Wen Models and tensor categories Give an introduction to the mathematical theory of tensor category and its applications to Levin-Wen models, which describe a large family of non-chiral topological orders. As known, the representation theory of groups can be used to classify phases, excitations or particles when the system adopts some kind of symmetry. Found symmetry is, however, not enough in some cases, such as topological order in which the relevant mathematical structures are tensor categories. First start with some basic things of general category theory. Then introduce the notion of a tensor category and a module category over it. There are a lot of structures that one can add to a tensor category. Introduce a few of them, which are relevant, such as the unitarity, semi-simpleness, rigidity, pivotal and spherical structures. These structures enable to express the tensor category in terms of directed labeled graphs, which also appeared in Levin-Wen Models. The representation theory gives an approach to describe the excitations in Levin-Wen Model. Don't deal with the excitation directly; instead, study the "boundary" of the excitation. With the tensor category structures, these "boundaries" form algebras and modules over algebras. Can classify the excitations by studying these algebras. This also corresponds to structures of the tensor category and its module category. *********************************** 8. Large momentum large frequency behavior of dynamicstructure factor (DSF) in 1-D repulsive boson gas-An introduction of a series Universal relations and the application of OPE method in cold atom physics Recently (from 2008 to now), a series of universal relations are discovered in atomic quantum gas where the interaction range is much smaller than any other length scales in the system. These relations set up a bridge between the short range (or high energy) correlations of the many-body wave function and the macroscopic properties of the system. The original proof of such relations involves novel mathematic methods and generalized functions first introduced. Later, another derivation involving OPE (Operator Product Expansion) theory and standard renormalization procedure is introduced. It was found that the OPE method is a very proper framework to investigate the short range properties of a system with contact interaction and the method is easy to generalize to give additional universal relations. In this talk,briefly introduce the application of OPE method in cold atom physics and review several important universal relations. Then introduce recent work, with cooperating, in related field in 1-D system. By combining OPE method with few-body Beth-Ansatz wave function, obtain a general asymptotic form of DSF in high frequency limit. ************************************ 9. The beauty from the dirty -- recent challenges in Anderson localization In the past fifteen years, an unprecedented degree of control reached in experiments with optical systems and ultracold atomic gases has triggered a "silent revolution" in studies of Anderson localization. In the first part of this talk, present a brief review of the state of the art in localization. In the second part of this talk, Focus on the recent challenges in this field -- localization in open media. Introduce recent experimental and theoretical studies showing that the interplay between wave interferences and the wave energy leakage at the boundaries may lead to very rich localization physics. Then,introduce an unconventional diffusive phenomenon—the local diffusion phenomenon—in open media. ************************************ 10. The Fate of the Vacuum The vacuum is essentially defined by the absence of what is known or believed to exist. As a consequence, the concept of vacuum and its possible existence have always been linked to fundamental questions in physics. Describe the evolution of ideas starting from the sixteenth century up to the beginning of twenty first century, from the discussion of falling bodies to dark matter and dark energy. ************************************** 11. Biclique Cryptanalysis, with an Application to the AES Since Rijndael was chosen as the Advanced Encryption Standard (AES), and became the global encryption standard, improving upon 7-round attacks on the 128-bit key variant or upon 8-round attacks on the 256-bit key variant is considered to be one of the most difficult challenges in the cryptanalysis of block ciphers for more than a decade. Present a novel approach to key-recovery using so-called bicliques.This allows to obtain for the first time results on a higher number of rounds, yet the advantage over brute-force search may become small.In contrast to most shortcut attack settings on AES versions, do not need any related-keys. The approach is practically verified to a large extent, yet its full implementation needs prohibitively large computational resources. *************************************** 12. Gutzwiller Projected wavefunctions in the fermonic theory of S=1 spin chains Based on the fermionic mean field theory for spins, develop the Gutzwiller projection method for the BCS-type mean field states of S = 1 systems. Through variational Monte Carlo (VMC) approach, use the projected wavefunctions to approximate the ground state. Study the S = 1 bilinear-biquadratic model $H=sum_i Jmathbf S_icdotmathbf S_{i+1} +K(mathbf S_icdotmathbf S_{i+1})^2$ and find that the optimized projected wavefunction is very close to the ground state when there is gap. The topology of the mean field state is important. After projection the topologically non-trivial states (weak pairing states) correspond to the Haldane phase, while the topologically trivial states (strong pairing states) fall in the dimerized phase. The transition point obtained from VMC is very close to the exact result. The correspondence between weak/strong pairing and Haldane/dimerized phase can be explained by the Z2 gauge uctuations around the mean field ground state. **************************************** 13. Spin-transfer torques and emergent electrodynamics in magnetic skyrmion crystals A Skyrmion crystal -- a lattice of topologically stable magnetic whirls -- can be stabilized in chiral magnets in a finite magnetic field range and it has been identified so far in several metallic compounds like MnSi, FeGe or Fe_{1−x}Co_xSi. Such magnetic skyrmions couple efficiently to spin-currents resulting in observable spintronic phenomena in a bulk material at low current densities of order 10^6 A/m^2. First, a spin-current can induce a finite spatial rotation of the skyrmion lattice, which can be understood as a double-transfer of angular momentum: in addition to the usual spin-transfer torque, angular momentum is transferred from the magnetic texture to the ionic crystal lattice giving rise to a mechanical torque resulting in a rotation of the skyrmion lattice. Second, a moving skyrmion lattice leads to artificial electric and magnetic fields that act on the electrons and which were recently detected by Hall Effect measurements. As the electron spin constantly adapts to the skyrmion texture, its orbital motion experiences an artificial magnetic field of one flux quantum per skyrmion. If the applied electric current exceeds a threshold value, the depinning of skyrmions results in a moving magnetic texture that induces an artificial electric field via Farady's law of induction. The resulting emergent artifical electrodynamics promises to become an interesting playground for novel spintronic phenomena. ***************************************** 14. Zero Correlation Linear Cryptanalysis with Reduced Data Complexity Zero correlation linear cryptanalysis is a novel key recovery technique for block ciphers proposed. It is based on linear approximations with probability of exactly 1/2 (which corresponds to the zero correlation). Some block ciphers turn out to have multiple linear approximations with correlation zero for each key over a considerable number of rounds. Zero correlation linear cryptanalysis is the counterpart of impossible differential cryptanalysis in the domain of linear cryptanalysis, though having many technical distinctions and sometimes resulting in stronger attacks. Propose a statistical technique to significantly reduce the data complexity using the high number of zero correlation linear approximations available. Also identify zero correlation linear approximations for 14 and 15 rounds of TEA and XTEA. Those result in key-recovery attacks for 21-round TEA and 25-round XTEA, while requiring less data than the full code book. In the single secret key setting, these are structural attacks breaking the highest number of rounds for both ciphers. ***************************************** 15. The rotational invariants constructed by the products of three spherical hARMonic polynomials H. Weyl (1946) established a theorem on the important structure for rotational invariants. Biedenharn and Louck in their famous Encyclopedia of Mathematics on Angular Momentum in Quantum Physics (1981) studied the most important case (n=3) of the general theorem in some detail. However, they pointed out in their book: “Unfortunately, the expression for the general coefficient has not been given in the literature and one has had to work out these invariant polynomials from the definition”. Have solved completely the problem raised by Biedenharn and Louck and present the expressions for the coefficients generally and explicitly in this talk. ******************************************** 16. Fluctuations, stability, and phase transitions in Larkin-Ovchinnikov states: quantum liquid crystals Motivated by polarized Feshbach-resonant atomic gases, discuss the nature of low-energy fluctuations in the putative Larkin-Ovchinnikov (LO) state. Because the underlying rotational and translational symmetries are broken spontaneously, this gapless superfluid is a quantum smectic liquid crystal, that exhibits fluctuations that are qualitatively stronger than in a conventional superfluid, thus requiring a fully nonlinear description of its Goldstone modes. Consequently, at nonzero temperature the LO superfluid is an algebraic phase even in 3d. It exhibits half-integer vortex-dislocation defects, whose unbinding leads to transitions to a superfluid nematic and other phases. In 2d at nonzero temperature, the LO state is always unstable to a charge-4 (paired Cooper-pairs) nematic superfluid. Expect this superfluid liquid-crystal phenomenology to be realizable in imbalanced resonant Fermi gases trapped isotropically. ********************************************* 17. P-wave superfluidity Discuss novel physics associated with p-wave superfluidity, driven by p-wave Feshbach resonance as for example observed in Rb85-Rb87 bosonic mixtures and K40 fermionic gases. ***************************************** 18. Strange Elasticity of Liquid-Crystalline Rubber After a general introduction to phases and phase transitions, discuss a fascinating phenomenology of liquid-crystalline rubber, an exotic material that is an amalgam of conventional liquid-crystals and rubber. While a solid in many respects, because of an interplay between its orientational and elastic degrees of freedom, some of its elastic constants vanish identically in this _solid_ liquid-crystal. Consequently, in some ways this solid behaves like a liquid. For example, in its nematic state, it can be stretched in some directions as much as 400% at virtually zero stress. Discuss some theoretical basis for the bizarre behavior of such oxymoronic materials, that are of considerable basic and applied interest. ****************************************** 19. Observation of quantum criticality with ultracold atoms in optical lattices Critical phenomena emerge when a many-body system is in the proximity of a continuous phase transition. Quantum criticality, in particular, anticipates universal properties of a system near a transition driven by quantum fluctuations at low temperatures, providing the key to understanding many diverse natural systems ranging from subatomic particles to black holes in the universe. Ultracold atoms offer a clean system to test these predicted universal properties. In this talk, share our recent observation of quantum criticality with two-dimensional Bose gases in optical lattices. On the basis of in situ density measurements, observe scaling behavior of the equation of state at low temperatures, locate the quantum critical point, and constrain the critical exponents. Our method holds promise for identifying general quantum phase transitions and for studying how critical systems evolve over time. In addition, I will briefly discuss our recent upgrade of imaging setup for higher resolution with a custom-designed microscope objective. +++++++++++++++++++++++++++++++++++++++++ ***************************************** 20. Frontiers in Anderson localization of classical waves Measurements of microwave and optical propagation of diffusive and localized waves I will discuss the challenges in measuring the statistics of steady state and pulsed microwave and optical propagation in random media as well as the surprising confluence of factors that make it possible to make detailed and accurate measurements. These measurements give the statistics over a random ensemble of statistically equivalent samples as well as the statistics within a single sample. Statistics in single samples are crucial for imaging, focusing and enhanced transmission in random media with potential applications in biomedical imaging and telecommunications. The essence of our findings is captured in a string of relationships between localization parameters that encapsulate diverse aspects of wave propagation. These include the average value, fluctuations and correlation of intensity, total transmission and conductance, the participation number of transmission eigenvalues and the ratio of the width and spacing of modes of the random medium. Finally discuss efforts to find the energy distribution within random samples and to relate this to characteristics of transmitted radiation. ***************************************** 21. Transport of Localized Waves in Open Media Since the concept of wave localization in random media was first proposed by P.W. Anderson more than 50 years ago, Anderson localization has become an important phenomenon in condensed matter physics. The phenomenon is ubiquitous in wave propagation in random environments including electrons in dirty metals, classical waves in random media and matter waves in random potentials. In the first part of this talk, a brief introduction of the Anderson localization will be given. In particular, some important concept and theory will be mentioned and discussed such as the weak localization (WL) effect, which is the most important wave interference effect that causes the localization of waves, and the self-consistent localization theory (SCLT). In 2000, SCLT was generalized to random systems in open media and the concept of position-dependent diffusion coefficient was introduced. In the second part of talk, some results of recent studies on the static and dynamic transport of localized waves in both one-dimensional and quasi-one-dimensional open media will be presented. In particular, it will be shown that the SCLT with position-dependent diffusion coefficient fails to describe the dynamical microwave transmission measurements at long times. This strongly indicates the importance of resonant transmissions in the transport of waves in localized samples. A dynamic single parameter scaling model that incorporates only isolated resonant transmissions and ignores necklace states will be discussed. In the static limit, an analytic result obtained by using supersymmetric field theory will be presented. It is shown that the theory is capable of capturing all rare resonant transmissions and gives rise to a novel scaling behavior for the local diffusion coefficient. ******************************************* 22. Improved Attacks on Multiple Encryption Multiple encryption schemes use a basic cryptographic scheme k times with independent n-bit keys in order to enhance its security. Typical examples of such schemes are double-DES and triple-DES, whose keys are 2*56 and 3*56 bits long, respectively. The security of such schemes had been studied extensively over many years, but all the known attacks on them (which are guaranteed to succeed) require time T and memory M whose product is at least 2^{kn}. In this talk present the first attacks on multiple encryption which break this bound, such as an attack on k=7 consecutive encryptions which require time of T=2^{4n} and memory of M=2^n, whose product is only TM=2^{5n} instead of the expected TM=2^{7n}. These attacks use a new technique called Dissection, which can be used to solve many combinatorial search problems which are unrelated to cryptography (such as the knapsack problem) with an algorithm which is more efficient than the best previously known techniques. ****************************************** 23. Looking for electron out-of-roundness below 10^-28 centimeters The electron's electric dipole moment (eEDM) will be sensitive to particle physics beyond the standard model. Make use of the extreme electric fields found within a molecular bond to pursue an experiment to improve current limit of eEDM. Give an overview of the principles and the implementations of our experiment in JILA. ****************************************** 24. Special Superconductivity and Cold Atoms The most unconventional superconductor: Sr2RuO4. After 18 years, what be known? 18 years after the discovery of superconductivity in the perovskite Sr2RuO4, basic questions about the nature of the superconducting order parameter remain. Almost immediately after the discovery of superconductivity, it was realized theoretically that it might be a chiral p-wave state, the solid-state analogue of the A-phase of superfluid Helium 3. If so, it would be the only known example so far of this exotic time-reversal symmetry-breaking state in electronic systems. After more than a decade and a half of intense experimental effort, however, the question of whether Sr2Ru04 is chiral p-wave still lacks a definitive answer. In this talk, review some of these experiments as well as theory, highlighting signatures of time-reversal symmetry-breaking coming from Kerr rotation measurements as well as the seeming absence of topological time-reversal symmetry-breaking edge currents implied by SQUID microscopy experiments. Argue that the multiband nature of Sr2RuO4 and its large spin-orbit coupling will likely play a central role in interpreting these experiments. **************************************** 25. Self-localization of a single hole in Mott antiferromagnets Anderson localization -- quantum suppression of carrier diffusion due to disorders -- is a basic notion of modern condensed matter physics. Here talk about a novel localization phenomenon totally contrary to this common wisdom. Strikingly, it is purely of strong interaction origin and occurs without the assistance of disorders. Specifically, by combined numerical (density matrix renormalization group) method and analytic analysis, show that a single hole injected in a quantum antiferromagnetic ladder is generally self-localized even though the system respects the translational symmetry. The localization length is found to monotonically decrease with the increase of leg number, indicating stronger self-localization in the two-dimensional limit. Find that a peculiar coupling between the doped charge and the quantum spin background causes quantum interference among different hole paths. The latter brings the hole's itinerant motion to a halt, a phenomenological analogy to Anderson localization. Findings are opposite to the common belief of the quasiparticle picture for the doped hole and unveil a completely new paradigm for lightly doped Mott insulators. **************************************** 26. Viscosity of Strongly Interacting Fermions Transport in strongly interacting quantum fluids is of great interest in diverse areas of physics — condensed matter, black holes and string theory, quark-gluon plasmas and cold atoms — which, at first sight, appear to have little in common. In this talk focus on the bulk and shear viscosity of ultracold Fermi gases, for which the most controlled experiments are possible. First discuss connections between transport and thermodynamics across the entire BCS-BEC crossover using exact sum rules. Describe implications for the strongly interacting unitary regime in 3D where scale invariance leads to particularly interesting predictions. Then discuss recent results that give insight into why experiments on 2D Fermi systems appear to show scale invariance at low energies. ****************************************** 27. The Bosonic Quantum Hall States It has been a long sought goal in cold atom research to realize bosonic quantum Hall states. This search is now further intensified due to some aggressive research initiatives recently announced in the United States. In this talk, point out a natural and practical way to generate the bosonsic Laughlin state and Pfaffian state. This method is a novel version of "BEC-BCS crossover" captured by a number of mathematical identifies discovered in the 16th century. If time permits, also describe the new research initiatives in the United State that actively bring together the condensed matter and the cold atom communities to pursue some highly ambitious goals. ******************************************* 28. Recent Progresses in Topological Superconductor and Superfluid The study of topological superconductors and superfluid which host Majorana zero bound states (MZBS) has developed into a rapidly growing branch of condensed matter physics, driven both by the pursuit of exotic fundamental physics and the applications in fault-tolerant topological quantum computation (TQC). In this talk present an overview for the theoretical and experimental results for topological superconductors and superfluid, focusing on 1D and 2D systems. For 2D system, the Majorana zero mode exists in the vortex core and for 1D system such zero modes exist in the boundary. This talk is organized in three parts. The first part will review the fundamentals of the topological superconductors and superfluid. Then, I will focus on the recent progresses in observing Majorana zero modes in solid state systems. Finally, present some recent studies of topological superfluid in cold atom systems. ****************************************** 29. RENORMALIZATION GROUP: AN INTRODUCTION The renormalization group has played a crucial role in 20th century physics in two apparently unrelated domains: the theory of fundamental interactions at the microscopic scale and the theory of continuous macroscopic phase transitions. In the former framework, it emerged as a consequence of the necessity of renormalization to cancel infinities that appear in a straightforward interpretation of quantum field theory, and of the freedom of then defining the parameters of the renormalized theory at different momentum scales. In the statistical physics of phase transitions, a more general renormalization group, based on a recursive averaging over short distance degrees of freedom, was later introduced to explain the universal properties of continuous phase transitions. The renormalization group of quantum field theory now is understood as the asymptotic form of the general renormalization group in some neighbourhood of the Gaussian fixed point.Therefore, in the framework of statistical field theories relevant for simple phase transitions, explain first the perturbative renormalization group.Then review a few important applications like the proof of scaling laws and the determination of singularities of thermodynamic functions at the transition. Then generalize the results to critical dynamics.Finally, describe the general renormalization group also called functional or exact renormalization group. ************************************** 30. Heat Conduction in Low Dimensional Momentum Conserving Lattices In the past decades, the extensive analytical, numerical and experimental studies have strongly suggested that in the low dimensional (i.e., one and two dimensional) momentum conserving systems, the heat conduction behavior does not follow the Fourier Law and can be classified into several universal classes [1, 2]. However, recently we find that in low dimensional lattices, the asymmetric inter-particle interactions may generally result in the normal heat conduction [3, 4]; Meanwhile, in the lattices without the asymmetric inter-particle interactions, the anomalous heat conduction behavior can be significantly distinct from the known universal classes [5]. These results suggest that it is important to clarify to what an extent the conventional hydrodynamic theories can be applied to the low dimensional heat conduction problem and it is necessary to take into consideration the underlying dynamical mechanisms. ********************************************* 31. Quaternionic analytic Landau levels in 3D and 4D The usual 2D Landau levels arise from the cyclotron motion of electrons in magnetic fields which crucially rely on the planar geometry. The complex analyticity of the lowest Landau level wavefunctions is essential for the study of fractional quantum Hall states. On the other hand, the current study of 3D topological insulators is largely confined to lattice systems. The complicated Bloch-wave wavefunctions and dispersive energy spectra are an obstacle for the study of fractional high dimensional topological states. Would like to go back to Landau levels for high dimensional topological states because they are explicit and elegant. Identify their connections to quaternions which are the first non-commutative division algebra discovered by Hamilton in 1843 and whose analytic properties were developed by Feuter. Simple Hamiltonians are constructed in the continuum by coupling spin-1/2 fermions with the SU(2) Aharanov-Casher potential. They exhibit flat SU(2) Landau levels in which orbital angular momentum and spin are coupled with a fixed helicity. The lowest Landau level wavefunctions satisfy the Cauchy-Riemann-Fueter condition of quaternionic analyticity. Each Landau level contributes one branch of gapless helical Dirac modes to the surface spectra. These results are also generalized to Dirac electrons, which can be viewed as a quaternionic generalization of the 2D Dirac Landau level problem. The zeroth Landau levels of Dirac fermions are a branch of half-fermion Jackiw-Rebbi modes which are degenerate over all the high dimensional angular momentum quantum numbers. Have also studied the 4D quantum Hall effects of the SU(2) Landau levels in the Landau-type gauge, which exhibit quantized non-linear electromagnetic response as a spatially separated chiral anomaly. Expect that the quaternionic analytical properties of Landau levels and the spectra flatness will further facilitate the study of high dimensional fractional topological states. ******************************************* 32.Spin polarized transmission of holes in quantum point-contacts with strong spin-orbit coupling Investigate quantum point contacts (QPCs) fabricated from GaAs two-dimensional hole gases. Show that several surprising aspects of magnetic focusing experiments can be understood form the presence of a crossing point at finite momentum of the lowest two spin subbands. The crossing point originates in one-dimension from a strong two-dimensional Rashba spin-orbit interaction of holes in asymmetric quantum wells, with a non-linear (cubic) dependence on momentum. Also discuss how a magnetic field parallel to the channel, or an asymmetry in the QPC lateral potential, can remove the degeneracy at the crossing point. These features allow to explain the anomalous sign of the spin polarization filtered by the QPC, as well as a surprising non-monotonic dependence of spin-polarization on magnetic field. Controlling the magnitude of the spin-splitting affords a novel mechanism for inverting the sign of the spin polarization. ******************************************** 33. Experimental observation of the quantum anomalous Hall effect in topological insulators The anomalous Hall effect was discovered more than 130 years ago in ferromagnetic materials, in which a Hall resistance exists even in the absence of external magnetic field. The quantized version of the anomalous Hall effect has attracted much interest since the discovery of quantum Hall effect in the 1980s. A few years ago, it was proposed that quantum anomalous Hall effect may occur in magnetically doped topological insulators, but the experimental realization has been elusive. In this talk report transport studies of topological insulator thin films grown by molecular beam epitaxy. The main focus will be on the tuning of the electronic structure, magnetic ordering, and bulk band topology, which led to the experimental realization of the quantum anomalous Hall effect, i.e., the quantum Hall effect in zero magnetic field. ********************************************* 34. Galois Theory The solution of linear and quadratic equations are well-known by all ancient civilizations. However the methods for solving cubic and quartic equations were not discovered until the Renaissance. French mathematician Vieta and Lagrange made pioneering contributions to theories of algebraic equations. Nearly all prestigious mathematicians at that time had ever tried to solve quintic equations but all of them just failed. In the early 1800s', Norwegian mathematician N.Abel and Italian mathematician Ruffini proved that a general quintic equations can not be solved by radicals. However, they did not give a real quintic equations that cannot be solved by radicals.During the 1820s', a young French mathematician Evariste Galois successfully and completely solved similar problems and built up the foundations of modern algebra.In this talk,give a brief introduction on how to solve cubic and quartic equations and the relation of algebraic equations and permutation groups. Next, give an introduction to Galois theory and prove the insolvability of quintic equations using Galois theory. ******************************************** 35. Highly polarized limit of the quasi-2D Fermi gas An ultracold gas of fermionic atoms with short range interactions represents a unique playground for studying pairing and effective interactions in a strongly correlated system due to the fine control of dimensionality and interactions. In this talk, start by reviewing recent theoretical and experimental progress in the field. Focusing next on the highly polarized limit of the quasi-2D Fermi gas, discuss properties of the quasiparticles which a single impurity can form when immersed in a Fermi sea, and the resulting ground state phase diagram as a function of mass imbalance. Show how the ground state transition of the attractive branch is shifted by the quasi-2D confinement and how this can be described quantitatively throughout the 2D to 3D crossover. Also demonstrate how the fast decay of the repulsive branch precludes itinerant ferromagnetism in this system. ********************************************* 36. Two-dimensional dipolar Fermi gases Ultracold atomic gases provide an exceptionally clean and controllable system in which to explore quantum many-body phenomena. Thus far, the focus has been on short-range interactions, since these well describe atom-atom scattering in the low energy limit. However, the recent creation of polar molecules with electric dipole moments has ignited interest in long-range dipolar interactions. In this talk, examine the phases of a two-dimensional gas of fermionic polar molecules, where the molecule dipole moments are all aligned by an external electric field. Show that such a gas can spontaneously break rotational symmetry and form a density wave (or stripe phase) for sufficiently strong repulsive interactions. This provides a model example of a density wave that is purely driven by repulsion rather than, e.g., distortions of an underlying lattice. ****************************************** 37. Solvable Lattice Gas Models With Three Phases Utilizing the brilliant solution by Onsager and Kaufman of the two-dimensional (2D) Ising model, a lattice gas model was constructed by Lee and Yang in 1952 for which the two phase region in its p-V diagram is analytically known. In the present work, we construct duplex models which have three phases, not just two, and for which the phase boundary in p-T diagrams and in p-V diagrams can both be exactly calculated. These models have two sublattices, and long range order form separately in the sublattices, creating a kind of partial order. ****************************************** 38. Quantum Transport in Spin-Orbit Systems Electronic systems with strong spin-orbit coupling and their transport properties are at the core of various important areas in condensed matter physics and associated applications, ranging from spin-Hall effect and spintronics to topological insulators and majorana fermions. Recently, it also becomes possible to create atomic quantum gases (both bosonic and fermionic) with “synthetic” spin orbit coupling, realizing a tunable cold atom “quantum simulator” to explore spin-orbit physics and related novel quantum phases. In this talk, discuss a few experiments in my laboratory studying quantum transport in an electronic topological insulator (featuring both the topological surface state and a Rashba spin orbit coupled 2D electron gas) as well as a spin-orbit coupled atomic Bose-Einstein condensate (BEC). Show how to generate spin polarized transport and probe spin-momentum locking in both systems, and discuss possible interplay between spin-orbit coupling and superconductivity or superfluidity. ******************************************** 39. NONLINEAR QUANTUM LIQUIDS IN ONE DIMENSION The conventional description of one-dimensional quantum fluids is based on the Luttinger liquid theory. In that theory, the true energy-momentum relation of particles making up the fluid is replaced by a linear one. This simplification is crucial for the theory, and abandoning it has proven to be difficult. The talk presents a breakthrough which allowed one to circumvent the difficulty. The new theory describes dynamic responses of a fluid consisting of particles with a generic spectrum. It is applicable to a diverse group of systems, including, for example, electrons in quantum wires and cold atomic gases in one-dimensional traps. ******************************************* 40. Cosmology reaching out to particle physics Modern cosmology is closely connected to particle physics. Not only understanding of the structure, evolution and matter/energy content of the Universe rely on particle physics, cosmological conditions and astronomical objects also provide a test bed for particle physics. An overview of such connection will be presented. ******************************************** 41. Numerical Modeling of Accretion Disks: A Journey with Magnetorotational Instability Accretion disks are ubiquitous in astrophysical systems, and are of fundamental importance for studying the formation and evolution of a wide range of astrophysical objects. Accretion requires efficient outward transport of angular momentum, with the most powerful mechanism being the turbulence generated by the magnetorotational instability (MRI). Characterizing the physical properties of the MRI turbulence requires large magnetohydrodynamic (MHD) simulations. Over the past two decades, significant progress has been made, yet many open questions still remain. Review the basic results as well as the most recent progress on the numerical study of the MRI, divided into three categories: local simulations without vertical stratification, local simulations including vertical stratification, and global simulations. Additional physics such as non-ideal MHD effects with applications to protoplanetary disks will also be briefly discussed. Simulation results highlight the importance of large-scale magnetic flux and its coupled evolution with accretion disks. *********************************************** 42. Quantum Statistical Mechanics, L-series, and Anabelian Geometry The talk is based on joint work with Gunther Cornelissen. Show how quantum statistical mechanical systems associated to number field provide complete invariants that permit the reconstruction of the number field up to isomorphism, even though some of their main constituent elements by themselves (the abelianized Galois group, the Dedekind zeta function, and the ring of adeles) are not complete invariants. In particular, using these quantum statistical mechanical methods, obtained a new purely number theoretic result, showing that a number field can be reconstructed from the associated family of L-functions with Grossencharacter. ******************************************** 43. Phases of correlated fermions on graphene-like lattices Graphene-like lattices offer in spite of lacking geometric frustration a promising playground for novel phases for fermions due to enhanced fluctuations as a result of low dimensionality, low coordination, and a vanishing density of states at the neutrality point. Review in this talk different phases appearing in quantum Monte Carlo simulations due to correlation in interplay with structure in single layer and bilayer systems, spin-orbit interaction, and a number N > 2 of flavors. The latter case, originally introduced by theoretical motivations can nowadays be realized experimentally with ultra-cold alkaline-earth atoms in optical lattices. ********************************************** 44. Simple physics of graphene: study by analogy After a brief general introduction into the physics of graphene, discuss similarities between the charge transport in graphene and the propagation of light in dielectrics, and present recent results on effects of disorder on these processes. ************************************************ 45. Dirac vs. Weyl in topological insulators: Adler-Bell-Jackiw anomaly in transport phenomena Dirac metals (gapless semi-conductors) are believed to turn into Weyl metals when perturbations, which break either time reversal symmetry or inversion symmetry, are employed. However, no experimental evidence has been reported for the existence of Weyl fermions in three dimensions. Applying magnetic fields near the topological phase transition from a topological insulator to a band insulator in Bi1-xSbx, observe not only the weak anti-localization phenomenon in magnetoconductivity near zero magnetic fields (B < 0.4 T) but also its upturn above 0.4 T only for E // B. This “incompatible” coexistence between weak anti-localization and “negative” magnetoresistivity is attributed to the Adler-Bell-Jackiw anomaly (“topological” term) in the presence of weak anti-localization corrections. ************************************************ 46. An Entangled Trio: Gravity, Information and Condensed Matter The three subjects of this workshop seem to belong to distant domains of scientific inquiry, but they are in fact intimately related. Gravity and Information were first linked up by Hawking who understood that the information (entropy) carried by a black hole manifests itself as a horizon area and concluded that black hole evaporation leads to a baffling loss of information. Gravity and Condensed Matter came together with the discovery of the AdS/CFT correspondence, a duality between gravitational theories and our most robust formalism for studying critical systems. Information, or quantum entanglement, has a profound importance in Condensed Matter physics: it is used to distinguish exotic phases of matter, but also to model critical systems in lattice settings by using tensor networks. In the last decade, have learned that these and similar connections run deeper than was previously appreciated. Many new interrelations have been proven and conjectured, including the assertions that entanglement is the glue that keeps spacetime from falling apart or that spacetime is a tensor network. In this workshop,try to prove or disprove a few such statements, conjecture new ones, and learn the true meaning of “It from Bit.” *********************************************** 47. Symmetry Fractionalization in Two Dimensional Topological Phases Symmetry fractionalization describes the fascinating phenomena that excitations in a 2D topological system can transform under symmetry in a fractional way. For example in fractional quantum Hall systems, excitations can carry fractional charges while the electrons making up the system have charge one. An important question is to understand what symmetry fractionalization (SF) patterns are possible given different types of topological order and different symmetries. A lot of progress has been made recently in classifying the SF patterns, providing deep insight into the strongly correlated experimental signatures of systems like spin liquids and topological insulators. In this lecture, review recent developments on this topic. First, it was shown that the SF patterns need to satisfy some simple consistency conditions. More interesting, it was realized that some seemingly consistent SF patterns are actually `anomalous', i.e. they cannot be realized in strictly 2D systems. Review various methods that have been developed to detect such anomalies. Applying such an understanding to 2D spin liquid allows one to enumerate all potentially realizable SF patterns and propose numerical and experimental probing methods to distinguish them. On the other hand, the anomalous SF patterns were shown to exist on the surface of 3D systems and reflect the nontrivial order in the 3D bulk. Review examples of this kind where the bulk states are topological insulators, topological superconductors, or have other symmetry protected topological orders. ++++++++++++++++++++++++++++++++++++++++++++++ ********************************************** 48. Topology and Frustration in Quantum Materials An important theme lying at the frontier of physics is to discover and understand new quantum phases of matter beyond the standard textbook classification. In the past decade, several new families of real-world platforms, such as topological insulators and semimetals, iron-based superconductors, geometrically frustrated magnets, as well as ultracold atoms in optical lattices, have been realized and extensively studied, which significantly advances our knowledge of the so-called “quantum materials”. Topology and frustration represent two novel features that are frequently encountered in these exotic examples. This workshop aims at bringing together active researchers in this broad field. By exchanging and discussing observations of a wide range of systems,expect that this workshop will help share different perspectives on quantum materials and motivate further investigations. *********************************************** 49. BICEP: Finding Finger Prints of the Big Bang Describe the BICEP/Keck program, a series of South Pole-based experiments aiming to study inflation by measuring the B-mode polarization of cosmic microwave background radiation. The BICEP telescopes feature compact refractors and fully lithographic superconducting polarimeter arrays. In March 2014, BICEP2 reported a clear excess of B-mode polarization at angular scales corresponding to predictions from inflation. Describe what this measurement means, the current uncertainties regarding foregrounds, and how we are going to follow this up with Keck and BICEP3,the current and next experiment in the series. ****************************************** 50. Quantum simulation in optical superlattice Ultracold atoms in an optical lattice are promising candidates to study quantum many-body phenomena. Bichromatic superlattices provide a novel tool on this direction. In this talk, first give an overview of the experiments done in superlattices. Then focus on two recent experiments.First report the experimental realization of strong effective magnetic fields with ultracold atoms using Raman assisted tunneling in an optical superlattice. Studied the nature of the frustrated ground state in the presence of an effective staggered magnetic field from its momentum distribution and directly revealed the quantum cyclotron orbit of a single atom exposed to the magnetic field. In the next experiment, present the direct measurement of the Zak phase - the Berry phase acquired during an adiabatic motion of a particle across the Brillouin zone - for a dimerized optical lattice, which models polyacetylene. The experimental protocol consists of a combination of Bloch oscillations and Ramsey interferometry. This work establishes a new general approach for probing the topological structure of Bloch bands in optical lattices. *********************************************** 51. Two-fluid model and emergent states in heavy electron materials Heavy electron materials provide a useful prototype for exploring the underlying mechanism of unconventional superconductivity and new magnetism. Among them is the first d-wave superconductor CeCu2Si2 discovered in 1979. The last ten years have seen many important progresses such as novel quantum criticality, "hidden" order and topological Kondo insulator. However, still don't have a satisfactory microscopic theory after thirty years of research. In this talk, introduce a phenomenological model and show how it leads to a dramatic change in our interpretation of experimental observations and hence the discovery of new universal properties. Then discuss some recent progresses and the proposal of a new unified framework that may help us better understand heavy electron physics. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ********************************************************* 52. Topology and Geometry of the Quantum Hall Effect In this talk review some of the topological aspects of the quantum Hall effect, including topological Chern numbers, gapless edge excitations, gapped bulk quasiparticles with fractional charge, fractional and possibly non-Abelian statistics, and nontrivial entanglement spectra.Also discuss some recent experiments and theoretical understandings on the filling factor 5/2 state, which is believed to be the Moore-Read state or its particle-hole conjugate. In the second part explain how one can introduce a family of wavefunctions with identical topological characteristics, but with different geometrical information, encoded in the so-called guiding-center metric, which was proposed by Haldane for quantum Hall systems with anisotropic mass or interaction. The quantification of the guiding-center metric and the breakdown of the anisotropic FQH state will be presented. ********************************************** 53. Two examples of one-dimensional cold gases in new many-body regimes Cold atom research has flourished in the direction of designing systems to quantum emulate important models in condensed matter physics. In this talk, however, focus on another different, exciting thrust, namely, to explore some unique aspects of cold atom systems. One of such examples is a one-dimensional Fermi gas of Feshbach tuned strong interaction and large spin population imbalance. Another system is interacting fermions on a two-leg ladder of unequal parity orbitals, which is derived from the experimentally realized double-well lattices by dimension reduction and is found topological. ***************************************** 54.Glass-like dynamics and dimensional crossover in the antiferromagnetic spin-ordered state in a photo-excited Nanoscale electronic ordering of charges, orbitals and spins are commonly observed in strongly correlated electron systems and they underlie important emergent material properties. Revealing their dynamics across the phase transition is an important scientific challenge. The ultrabright and ultrashort X-ray pulses produced by free electron laser and synchrotron light sources provide new opportunities to probe the dynamic evolution of electronic orderings using laser pump, ultrafast X-ray probe techniques. Here present our recent results on the dynamics of antiferromagnetic spin order across the photo-induced phase transition in a colossal magnetoresistance manganite Pr0.7Ca0.3MnO3 using ultrafast time-resolved resonant soft X-ray scattering spectroscopy. In the “melting” process, observed two time scales associated with electronic and lattice interactions respectively. The recovery process, however, shows exotic behavior that cannot be explained by electronic or lattice driven mechanism. Instead, the recovery of the spin ordering, measured over nearly 12 decades in time (70 ps to tens of seconds), exhibits a stretched-exponential behavior that is a hallmark of glass-like systems. Moreover, a dimensional crossover in the effective interaction from 1D at low pump fluence to 3D at high pump fluence is observed, suggesting that the spin ordering and orbital ordering are transiently decoupled. A microscopic picture consistent with all experimental observations is proposed and the role of spin order in the phase transition will be discussed. **************************************** 55. Topological states of matter in correlated electron systems Topological states of matter are protected by the nontrivial topology of the hamiltonian. States of different topologies are bridged either by gapless edge states in real space, or a quantum phase transition in the parameter space with gapless excitations at the transition point. The nontrivial topology is either an inheritage of the bare band structure (as in topological insulators), or generated spontaneously by the strong correlations between the electrons. On the latter we will focus in this talk. Consider both time-reversal-symmetry breaking (T-breaking) and invariant (T-invariant) states. 1) Since the spontaneous phase is a low energy phenomenon but the effective interaction follows from renormalization by virtual excitations at higher energy scales, discuss briefly an efficient functional renormalization group method to treat the hierarchy of energy scales and treat the variable phases on equal footing. 2) show that a doped graphene (near the van Hove filling) is a candidate for TRS breaking states, such as chiral-SDW and chiral d+id' superconducting states. The former leads to quantized anomalous Hall effect, while the latter to quantized thermal Hall conductivity. Show that similar situations occur in Kagome lattices at van Hove filling. Furthermore, with geometrical frustration richer phases appear in Kagome lattices. 3) Show that proximity to van Hove singularity, as well as small-q inter-pocket scattering are efficient mechanisms for ferromagnetic-like spin fluctuations. This leads to degenerate p-wave pairing channels. The degeneracy is easily broken by even a weak spin-orbital coupling, leading to a T-invariant topological superconducting phase. Bandstructure-wise, the normal state must have 2*(2n+1) spin-split fermi pockets (encircling T-invariant momenta) in order to have a strong T-invariant topological superconductor. The edge states of such a superconductor are Majorana fermions. Perspectives on promising materials are discussed. ************************************** 56. A new look at Rashba-related phenomena from multi-Title: A new look at Rashba related phenomena from multi orbital perspective Over the last few years have been developing a more realistic picture of the Rashba effect based on multi-orbital band structure ideas. The initiative hope, is a timely one in the sense that a great deal of efforts is being devoted to surface phenomena in bot both topological and non-topological material systems and various interface structures.Try to provide arguments that multi-orbital picture is an essential ingredient in the overall microscopic understanding of the Rashba interaction taking place in such systems. Even in the absence of substantial spin-orbit interaction, i.e. in bands formed by light elements, show that an analogue of spin Rashba effect is taking place,dubbed orbital Rashba effect. Experiments to detect orbital Rashba effect will be discussed. Several applications of the orbital Rashba ideas will be presented in connection with spin transfer torque dynamics, as well as Kondo effects, assumed to be taking place in ultrathin film materials. ***************************************** 57. Instability of three-band Luttinger liquids: renormalization group analysis and possible application to K2Cr3As3 Motivated by recently discovered quasi-one-dimensional superconductor K2Cr3As3 with D3h lattice symmetry, studdy one-dimensional three-or bital Hubbard models with generiic electron repulsive interaction described by intra-orbital repulsion U, inter-orbital repulsion U’, and Hund’s coupling J. As extracted from density functional theory calculation, two of the three atomic orbitals are degenerate and the third one is non-degenerate, and the system is presumed to be at incommensurate filling filling. With the the help help of of bosonization, have usual three three-band band Luttinger liquids liquids in the the normal normal state state.Possible charge density wave (CDW), spin density wave (SDW) and superconducting instabilities are analyzed by one-loop renormalization group. The ground state depends on the ratio J/U. For the physical relevant parameter region, 0 favored when 1/3 **************************************** 58.Quantum magnets in insulating structures have proven to be remarkable systems when subjected to a strong magnetic field. In addition to their own intrinsic interest they can be mapped on model systems of itinerant quantum particles. This has allowed to use them as quantum simulators for studying the properties of interacting hard core bosons. In particular focus on two recent ladder compounds for which a combination of numerical studies and analytical ones has allowed to obtain fully the dynamical correlation functions.Review the recent results in that respect, in particular some of the experiments and the corresponding theories for phenomena such as Bose-Einstein condensation and Tomonaga-Luttinger liquids as observed by neutrons, NMR and also ESR.Discuss the recent successes in this domain as well as several of the open problems and perspectives offered by such compounds such as the possibility to study dimensional crossover,disorder effects etc. ******************************* 59.Quantum Spins as quantum simulators Quantum magnets in insulating structures have proven to be remarkable systems when subjected to a strong magnetic field.In addition to their own intrinsic interest they can be mapped on model systems of itinerant quantum particles. This has allowed to use them as quantum simulators for studying the properties of interacting hard core bosons. In particular I focus on two recent ladder compounds for which a combination of numerical studies and analytical ones has allowed to obtain fully the dynamical correlation functions. Review the recent results in that respect, in particular some of the experiments and the corresponding theories for phenomena such as Bose-Einstein condensation and Tomonaga-Luttinger liquids as observed by neutrons, NMR and also ESR.Discuss the recent successes in this domain as well as several of the open problems and perspectives offered by such compounds such as the possibility to study dimensional crossover,disorder effects etc. ************************************** 60. Planetesimal Formation through the Streaming Instability The formation of kilometer-scale planetesimals is one of the most difficult stages in the course of planet formation around young stars. It is faced with several major barriers. Direct dust growth by coagulation is limited, up to mm to cm in size, due to inefficient sticking, bouncing, and fragmentation at collision. Even if the dust grains manage to grow past cm in size, they continually lose angular momentum to their surrounding gas due to constant head wind, leading to rapid orbital decay to the star. One promising mechanism for circumventing these barriers is the streaming instability, in which the solids actively participate in the dust-gas dynamics to concentrate themselves to high density, leading to direct gravitational collapse and the formation of planetesimals. Review current understanding of the streaming instability and planetesimal formation. Specifically, how the instability operates, under what conditions it drives strong concentration of solid materials, the initial mass function of the resulting planetesimals, and its interaction with turbulent gas will be examined. ********************************************* 61.Wind mass transfer in AGB binaries Wind mass transfer in AGB binary systems is poorly understood despite its importance in low-mass binary evolution. Many observable objects such as planetary nebulae and carbon-enhanced-metalpoor stars can be better understood if have a realistic picture of wind mass transfer. Wind mass transfer, if results in a high accretion rate, can also lead to a merger of the binary. To illustrate the wind mass transfer process, study the binary system that consists of an asymptotic-giantbranch (AGB) star and a companion star. Carry out 3-D radiation-hydrodynamic (RHD) simulations of AGB binaries that transfer mass through wind-Roche-lobe-overflow (WRLOF) and Bondi-Hoyle-Littleton (BHL) accretion. Our 3-D RHD model solves the radiative transfer by the raytracing method in an adaptive spherical coordinate. Also consider the optically thin cooling of HII, HI, H2, CO, and H2O by solving Saha’s equations. Simulation results show that circumbinary disk or spiral structure outflow may be found in different configurations of the binary systems.Accretion disk could form around the companion. Discuss the potential importance of chemistry and phase transition of gases in the evolution of AGB binaries. ********************************************* 62. Topologically protected quantum computation based on Majorana zero modes: A theory perspective Topological materials provide a protection from decoherence at the hardware level by using emergent non-Abelian anyons. The simplest non-Abelian anyon involves a defect that binds a Majorana zero-energy mode predicted to appear quite naturally in certain superconducting systems.First review recent progresses and discuss the challenges in Majorana search.Then, discuss a near term question: What is the simplest way to reveal the coherent signatures of Majorana devices and measure the qubit lifetime? To answer this question, propose a simple transport measurement in a Majorana Coulomb blockade device. Finally,discuss a serious type of error—diabatic error—in general topological quantum computation and Majorana qubits. Diabatic errors only vanish as a power-law function when increasing braiding operation time. This power-law behavior can wash out the advantages of topological quantum computation. Found a scheme to overcome this serious problem. ************************************** 63. Experimental quantum error correction with binomial bosonic codes Quantum error correction (QEC) is necessary for a practical quantum computer because of the inevitable coupling of quantum systems with the uncontrolled environment. A measurement-based QEC requires rapid extraction of error syndromes without disturbing the stored information and fast real-time feedback control for error corrections. Encoding quantum information on photonic states in a microwave cavity for QEC has attracted a lot of interests because of its hardware efficiency. This scheme benefits from the infinite dimensional Hilbert space of a harmonic oscillator for redundant information encoding and only one error syndrome that needs to be monitored. In this talk,describe our experimental realization of both repetitive QEC with a binomial bosonic code in a circuit quantum electrodynamics architecture and full control on the logical qubit [1]. The demonstrated binomial bosonic codes promise the realization of QEC-enhanced precision measurements and could also be further explored for fault-tolerant quantum computation.The quantum feedback control technique developed for this work also provides new perspectives for control and measurement of open quantum systems. ************************************** 64. Non-equilibrium control of the effective free energy landscape in a frustrated magnet Geometrically frustrated magnets often possess accidentally degenerate ground states at zero temperature. At low temperature, thermal fluctuations lift the accidental degeneracy and tend to stabilize ground states with maximal entropy. This phenomenon, known as “order by disorder”, underlines the fluctuation contribution to the free energy landscape in frustrated magnets. In this talk, show that one can control such free energy landscape in a nonequilibrium setting. In a frustrated magnet with precessional dynamics, the system’s slow drift motion within the degenerate ground state manifold is governed by the fast modes out of the manifold. Exciting these fast modes generates a tuneable effective free energy landscape with minima located at thermodynamically unstable portions of the ground state manifold. I demonstrate this phenomenon on pyrochlore XY antiferromagnet, where a magnetic field pulse is sufficient for controlling the effective free energy landscape at nonequilibrium. ********************************** 65.Generalized Lieb-Schultz-Mattis Constraints on Phases of Quantum Magnets Quantum magnetic systems with a large number of spins often enable the emergence of a great variety of interesting phases at zero temperature. Yet, there are fundamental constraints on the infrared behavior of quantum magnets from the ultraviolet data encoded in the microscopic lattice of spins. As the first and the most well-known example, the Lieb-Schultz-Mattis (LSM) constraint forbids trivial phases from arising in certain quantum magnets with SU(2) spin rotation and the lattice translation symmetries. As an important experimental consequence, it enables the confirmation of exotic phases like quantum spin liquids, whose intrinsic properties are often hard to probe directly, through the examination of the absence of spontaneous symmetry breaking which is more accessible with standard spectroscopy measurements. In this talk, present a new topological perspective of the LSM constraint. Show how the LSM constraint is related to the constraints on the surface modes of symmetry-protected topological states. Using this relation, Discuss a large class of generalizations of the LSM constraint incorporating different space groups (including both translations and point group symmetries) and different spin symmetries. The range of applicability of such generalized LSM constraints is vastly extended compared to the original version. Also discuss how the generalized LSM constraints enforce the “exoticness”of continuous phase transition quantum magnets. ********************************** 66. Machine learning meets quantum physics Recently, machine learning/artificial intelligence has attracted tremendous interest across different communities. In this talk,briefly introduce an emergent field of quantum machine learning/artificial intelligence---an interdisciplinary field that explores the interactions between quantum physics and machine learning/artificial intelligence. On the one hand, talk about several quantum algorithms that promise an exponential speed-up for machine learning tasks. On the other hand, show how ideas and techniques from machine learning can help solve challenging problems in the quantum domain. ********************************** 67. Exotic Spin Excitations of Quantum Magnets Quantum spin liquids (QSLs) represent a novel state of matter in which no spontaneous symmetry is broken and the spins remain in the liquid-like state even at absolute zero temperature. They hold great potentials in quantum computation and communication. Furthermore, it is believed that the understanding of QSLs may help solve the long-term puzzle of high-temperature superconductivity.For these reasons, QSLs have been studied extensively in the past 45 years, but so far there still appear to be no ideal QSL materials.In this talk, present our results on two types of QSL candidates, geometrically-frustrated compounds YbMgGaO4 and YbZnGaO4 with the triangular lattice, and a Kitaev material alpha-RuCl3 with the honeycomb lattice. For both YbMgGaO4 and YbZnGaO4,find that their true ground states to be spin glasses, and disorder is mainly responsible for the spin-liquid-like observations [1].For alpha-RuCl3, show that there is a dominant Kitaev interaction in the zigzag order state [2],and a magnetic field can drive the system from an ordered state into a possible QSL state [3,4].In the end,also briefly discuss our recent discovery of topological magnons in a threedimensional antiferromagnet Cu3TeO6 [5]. *********************************** 68.Topological invariants: classification and diagnosis In this talk,introduce the two theoretical papers and one numerical paper that lead to the establishing of the "Catalogue of Topological Electronic Materials". In the theoretical work, the collaborators exploited the theory of symmetry-based indicators (or topological quantum chemistry) and that of real-space construction of topological crystalline states, and found the exhaustive mappings from the symmetry eigenvalues of valence bands to their topological invariants. In the numerical work, these mappings are applied to designing a fully automated, fast diagnosis method for topological materials. The method is then used to find as many as 8000 topological materials among over 40000 materials that are registered in popular materials databases. A topological materials database is made based on these results. ************************************** 69. A new era of Galactic Archaeology Understanding physical processes responsible for the formation and evolution of galaxies like the Milky Way is a fundamental problem in astrophysics. However, a key challenge is that the properties and orbits of the stars can only be observed at present: to understand what happened in the Milky Way at earlier epochs, one must explore “archaeological” techniques. The Galactic archaeology landscape is rapidly changing thanks to on-going large-scale surveys (astrometry, photometry, spectroscopy, asteroseismology) which provide a few orders of magnitude more stars than before. In this talk, I will discuss new "phenomenological" opportunities with these surveys. I will introduce a new set of machine-learning tools for maximally harness information from spectra(LAMOST), photometric fluxes (Gaia) and light curves (TESS). I will also present the new opportunities in Galactic archaeology in the era of deep photometry,such as LSST and DES. *************************************** 70.Monopoles in algebraic spin liquids: towards a unified view on 2D quantum magnetism Quantum magnets provide the simplest example of strongly interacting quantum matter, yet they continue to resist a comprehensive understanding above one spatial dimension. In this talk discuss a single effective theory, Quantum Electrodynamics (QED3), that describes multiple orders on different two dimensional lattices in a unified framework. This theory includes photons, four flavors of Dirac fermions, as well as monopoles, an important class of excitations that drive confinement. By resolving the long standing open issue of monopoles and their symmetry properties, naturally account for various orders on both bipartite lattices such as the square and honeycomb as well as non-bipartite triangular and Kagome lattices. The theory points to two different scenarios for these two types of lattices. In particular, in spin models on non-bipartite lattices, the QED3 theory may be stabilized, giving rise to a stable algebraic spin liquid phase. *************************************** 71.Nonthermal Particle Acceleration in Magnetic Reconnection Magnetic reconnection is a commonly known multi-scale plasma process that quickly converts magnetic energy into kinetic energy in bulk plasma flow, thermal and nonthermal particle distributions. An important problem that remains unsolved is the acceleration of nonthermal charged particles in the reconnection region. In particular, the large-scale theory and 3D extension of this problem are poorly known. To shed more lights to this problem, we utilize a number of tools to resolve this problem. Using LANL’s VPIC code, study particle acceleration in magnetic reconnection via large-scale 3D kinetic simulations to examine several effects that may be important, including pre-existing fluctuations, kink and secondary tearing instabilities, and open boundary conditions. The results show that particle acceleration in reconnection layers is surprisingly robust despite the development of 3D turbulence and instabilities. Furthermore, the observed particle acceleration in the 3D simulations is sometimes more efficient than the corresponding 2D case, indicating viable new acceleration mechanisms.Then study the largescale reconnection acceleration by solving the Parker's transport equation in a background reconnecting flow provided by MHD simulations. Due to the compression effect, the simulations suggest fast particle acceleration to high energies in the reconnection layer. This study clarifies the nature of particle acceleration in reconnection layer, and may be important to understand particle acceleration and plasma energization during solar flares and other astrophysical environments. ************************************* 72.Neural networks and their applications in physical sciences Neural networks have gained much attentions in recent years due to their applications in various daily aspects including facial/voice recognition and data mining. Despite their remarkable ability,neural networks are severely underutilized and have not realized its full potential in physical sciences. In this talk, briefly explain the basic concepts as well as some exciting frontier ideas in neural networks. Discuss the opportunities of applying this simple yet interesting idea to physical sciences using my studies of the Milky Way as an example. In particular, describe how a combination of data-driven models and neural networks can be an effective tool to harness information from low-resolution spectra and to relate various fields in physical sciences -- such as the studies of spectroscopy and asteroseismology in astronomy. ************************************* 73. Dynamics of Dust-Gas Interactions in Protoplanetary Disks and Implications for Planetesimal Formation The majority of young low-mass stars are surrounded by disks, consisted of large reservoirs of gas and dust out of which planetary systems eventually form. In the recent years, high spatial resolution observations of such disks by ALMA have revealed many details that are providing interesting constraints on the disk physics as well as dust dynamics, both of which are essential for understanding planet formation. Carry out high-resolution, two-dimensional hydrodynamic simulations of global disks, including the effects of dust feedback.Find that disks display a rich variety of behaviors, depending on the mutual interactions of dust and gas. These features include both the quasi-axisymmetric rings and non-asymmetric dust traps which are unstable to several possible instabilities. Also show for the first time the effects of streaming instability in global disk simulations. These effects are providing a promising new way to promote the formation of many planetesimals in such disks. Produce synthetic dust emission images using our simulation results and discuss the comparison between simulations and observations. ************************************ 74. Quantum Griffiths Singularity in 2D Superconductors and Log-Periodic Quantum Oscillations in Ultra-quantum Topological Materials Quantum phase transition is one of most important topics in condensed matter physics. For the first time, observe the divergence of dynamical critical exponent for the superconductor-metal transion in ultrathin cyrtalline Ga films grown on GaN substrate, which is a the major signature of quantum Griffiths singularity and manifests a new quantum phase transition in 2D superconductors [1,2]. This discovery is further revealed in LAO/STO(110) interface superconductors [3] and monolayer NbSe2 films[4].It is well known that so far there are two classes of quantum oscillations. One is B periodic oscillations, such as AB and AAS effects for mesoscopic system and Little Parks oscillations for superconducting systems. The other one, i.e. 1/B periodic SdH oscillations from quantized Landau levels, might be more universal. However,discover a new class of quantum oscillations beyond quantum limit in high quality topological materials, showing exotic log B period. Further theoretical investigation reveals that the Efimovian bound states can explain the log-periodic quantum oscillations (i.e. discrete scale invariance) well. [5] ************************************ 75.Generalized modular transformations in 3+1D topologically ordered phases and triple linking invariant of loop braiding Previously, topologically ordered phases in 2+1 dimensions have been well studied, partially due to its close relation with 1+1D conformal field theory (CFT). In particular, the modular transformations,originally developed in the context of CFT, have been demonstrated to contain information on the braiding statistics of point-like particles and are characterizing features of topologically ordered phases in 2+1D. In this talk discuss the natural generalization of these in 3+1D topologically ordered phases, in which the generalized modular transformations are found to be directly related to the braiding of extended loop-like excitations. **************************************** 76. Dirac Materials: theory and materials modeling Dirac materials harbor Dirac Fermions, whose low-energy excitations are governed by the Dirac equation of relativistic quantum mechanics. Quite a number of materials of recent interest to the condensed matter community can be classified as Dirac materials, such as graphene, topological insulators and valleytronics materials. In this talk,introduce “Diracologygy”from the viewppoint of Berryy pphase, includingg related theories and computational aspects. This will be followed by recent progresses from my group in this direction of research, including (1)Materials prediction for realizing valleytronics; (2)Topological aspects of Z2 = 0 systems; (3)Time pp g ermitting: Chern insulator from a “trivial” oxide. ********************************** 77. Equilibration, Thermalization, and Entanglement in Quantum Many-Body Systems The most familiar fact of physics in experience is that physical systems spontaneously tend to reach equilibrium, and to thermalize. This very baisic fact has always been at odds with the fundamental laws of physics, that are time-reversal. In particular, Quantum dynamics in an isolated is unitary, reversible and no entropypy can increase. For a longg time, it has been speculated that observable quantities could thermalize even if the global system is in a pure state away from equilibrium. One of the mechanisms for this to happen is the Eigenstate Thermalization Hypothesis (ETH), that states that thermalization happens at the level of single eigenstates. Recently, people have understood that entanglement is at the root of this phenomenon, and these phenomena have become experimentally relevant in the setting of ultra cold atom gases . Moreover, there is a strong Interest in Those Systems That refuse to thermalize. In FACT, interesting Things happen Awayy from equilibrium. After All, there Si no one CAN extract Way Work (without other Changes) -to Give an example from an equilibrium state. Such states that refuse to thermalize are either fine tuned, or are those called Many Body Localized states. In this talk, I will present a current review of all these notions, and put forward some new problems and tentative direction of solutions . In Particular, Even though WE know That entanglement is Involved in thermalization and ETH,, ITS role is not Completely Understood,namely Because entanglement is very strong Even in Systems That do not thermalize. Show Some new results on the study of entanglement spectrum , suggesting that entanglement level statistics may contain the relevant information as to how ETH is obeyed or not. ************************************* 78. Mapping the phase diagram of spinor condensates via Title: Mapping the phase diagram of spinor condensates via adiabatic quantum phase transitions Experimentally study two quantum phase transitions in a sodium spinor condensate immersed in a microwave dressing field. In contrast to magnetic fields, microwave dressing fields can induce both negative and positive values of the quadratic Zeeman energy. Demonstrate that many previously unexplored regions in the phase diagram of spinor condensates can be investigated by adiabatically tuning a microwave field across across one one of of the the two two quantum quantum phase phase transitions transitions.This method method overcomes overcomes two two major major experimental challenges associated with some widely used methods, and is applicable to other atomic species. Agreements between our data and the mean-field theory for spinor Bose gases are also discussed. ***************************************** 79. A first glance of Noncommutative Geometry Follow Alain Connes' Lecon Inaugurale (first lecture) at College de France(1985), to show (in some sense) how the mathematical framework arised from the understanding of quantum physics leads to the idea of noncommutative spaces. And also talk about some further development if have time. ******************************************* 80. Topological states of matters in classical and quantum magnets topological states of matters in classical and quantum magnets Topological phases have been explored in various fields in physics such as semiconductor physics, correlated electron systems, liquid helium-3, cold-atomic systems, and photonics.This leads to the recent foundation of emerging materials such as topological band insulators,topological superconductors/superfluid and topological photonic crystals. In this talk, about two topological states of matters in magnets; one is topological spin waves in classical magnets and the other is multiple-polar states in quantum magnets. In the first part, propose magnetostatic spin-wave analog of integer quantum Hall state, in which spin wave propagation with long-wave length (micrometer scale) is driven by magnetic dipole-dipole interaction. Like in relativistic spin-orbit interaction, the dippolar interaction plays role of the spin-orbital locking, so that two-dimensional ferromagnetic thin films with periodic structuring can host spin-wave bands with non-zero Chern integers, which result in topological edge modes for spin-wave propagations. In the 2nd part of the talk,argue that a certain multiple-polar states in quantum magnets can be described as a Z2 topological order phase, hosting a similar low-energy effective gauge theory as Z2 quantum spin liquid. A variational ansatz derived from a “Z2 multiple-polar state” proposed in a quantum spin model can explain several unusual features found in preceding exact diagonalization studies on the same quantum spin model. ************************************* 81. Simple physics of Anderson localization: Simple physics of Anderson localization: generalities and applications The talk is a brief introduction into the physics of strong Anderson localization of waves.Present the main methods and results of the theoretical and experimental studies of wave propagation in one-dimensional disordered systems.The emphasis will be put on the description, detection and potential applications of the disorder-induced resonances. *********************************** 82. Detecting Majorana fermions in fully gaped and nodal Title: Detecting Majorana fermions in fully gaped and nodal topological superconductors An important progress has been made recently that zero bias conductance peaks (ZBCPs) in Andreev reflection type experiments, which are possibly due to Majorana fermions, have been observed in superconductor/semiconductor heterostructures. However, recent experiments cannot rule out other possible origins of the enhancement local Andreev reflections.In this talk, show that two spatially separated but strongly coupled Majorana fermions can strongly enhance crossed Andreev reflection amplitudes between two spatially separated leads, which are connected to the two Majorana fermions separately. The resulting strong current-current correlations and shot noise can be used to detect the non-local properties of Majorana fermions.The The creation creation and detection detection of Majorana fermions in the the so-called called DIII class class topological topologicalsuperconductors which preserve time-reversal symmetry will also be discussed.In this talk, also discuss the possibility of detecting Majorana fermions in nodal superconductors.Predict that Majorana fermion flat bands appear in d_{x^2-y^2}-wave superconductors with Rashba spin-orbit coupling. Unlike the zero energy fermionic Andreev bound states which appear on the [[110 110]] edges of usual usual d-wave wave superconductors, superconductors, the the Majorana fermions on the the same same edge edge cannot be lifted to finite energy by an in-plane magnetic field. Therefore, tunneling spectroscopy for a d_{x^2-y^2}-wave superconductor under an in-plane magnetic field gives rise to a triple peak feature with the central ZBCP caused by Majorana fermions. *********************************************** 83. A new era of Galactic Archaeology Milky Way is a fundamental problem in astrophysics. However, a key challenge is that the properties and orbits of the stars can only be observed at present: to understand what happened in the Milky Way at earlier epochs, one must explore “archaeological” techniques. The Galactic archaeology landscape is rapidly changing thanks to on-going large-scale surveys (astrometry,photometry, spectroscopy, asteroseismology) which provide a few orders of magnitude more stars than before. In this talk, discuss new "phenomenological" opportunities with these surveys. Introduce a new set of machine-learning tools for maximally harness information from spectra (LAMOST), photometric fluxes (Gaia) and light curves (TESS). Also present the new opportunities in Galactic archaeology in the era of deep photometry, such as LSST and DES. ********************************************* 84. Monopoles in algebraic spin liquids:towards a unified view on 2D quantum magnetism Quantum magnets provide the simplest example of strongly interacting quantum matter, yet they continue to resist a comprehensive understanding above one spatial dimension. In this talk discuss a single effective theory, Quantum Electrodynamics (QED3), that describes multiple orders on different two dimensional lattices in a unified framework. This theory includes photons, four flavors of Dirac fermions, as well as monopoles, an important class of excitations that drive confinement. By resolving the long standing open issue of monopoles and their symmetry properties, naturally account for various orders on both bipartite lattices such as the square and honeycomb as well as non-bipartite triangular and Kagome lattices. The theory points to two different scenarios for these two types of lattices. In particular, in spin models on non-bipartite lattices, the QED3 theory may be stabilized, giving rise to a stable algebraic spin liquid phase. ************************** 85. Nonthermal Particle Acceleration in Magnetic Reconnection Magnetic reconnection is a commonly known multi-scale plasma process that quickly converts magnetic energy into kinetic energy in bulk plasma flow, thermal and nonthermal particle distributions. An important problem that remains unsolved is the acceleration of nonthermal charged particles in the reconnection region. In particular, the large-scale theory and 3D extension of this problem are poorly known. To shed more lights to this problem, we utilize a number of tools to resolve this problem. Using LANL’s VPIC code, we study particle acceleration in magnetic reconnection via large-scale 3D kinetic simulations to examine several effects that may be important, including pre-existing fluctuations, kink and secondary tearing instabilities, and open boundary conditions. The results show that particle acceleration in reconnection layers is surprisingly robust despite the development of 3D turbulence and instabilities. Furthermore, the observed particle acceleration in the 3D simulations is sometimes more efficient than the corresponding 2D case, indicating viable new acceleration mechanisms.Then study the largescale reconnection acceleration by solving the Parker's transport equation in a background reconnecting flow provided by MHD simulations. Due to the compression effect, the simulations suggest fast particle acceleration to high energies in the reconnection layer. This study clarifies the nature of particle acceleration in reconnection layer, and may be important to understand particle acceleration and plasma energization during solar flares and other astrophysical environments. ************************************ 86. Neural networks and their applications in physical sciences Neural networks have gained much attentions in recent years due to their applications in various daily aspects including facial/voice recognition and data mining. Despite their remarkable ability, neural networks are severely underutilized and have not realized its full potential in physical sciences. In this talk, briefly explain the basic concepts as well as some exciting frontier ideas in neural networks. Discuss the opportunities of applying this simple yet interesting idea to physical sciences using my studies of the Milky Way as an example. In particular, describe how a combination of data-driven models and neural networks can be an effective tool to harness information from low-resolution spectra and to relate various fields in physical sciences -- such as the studies of spectroscopy and asteroseismology in astronomy **************************** 87. Superfluidity in one dimension as a dynamical phenomenon Superfluid density is often related to helicity modulus, which is a static response of the free energy to phase twist. In one dimension, the helicity modulus generally vanishes in the thermodynamic limit at finite temperatures, implying absence of superfluidity. Recently, however, experimental observation of super fluidity in liquid 4He confined in one-dimensional nanopore is reported [1]. This urges to reconsider the notion of superfluidity and its relation to the helicity modulus which is a completely static quantity. Develop a theory of superfluidity in one dimension, as an essentially dynamical phenomenon [2]. The result agrees qualitatively with the experimental results on liquid 4He in one-dimensional nanopore, and predicts a weak but significant frequency dependence of the onset of the superfluild response. +++++++++++++++++++++++++++ ***************************(Total No.87) 现代世界的高级量子理论发展与应用 1. 一维量子液体的动态相关函数 我将谈谈最近在理解一维液体动态特性方面的进展,这超出了线性化色散关系的卢廷格近似。 我将涵盖费米子液体和玻色子液体,并提到与许多完全可解的模型的关系。 *********************************** 2. 安全计算的算法(第1,2部分) 我们调查了在各种密码设置中设计用于安全计算和通信的有效协议的一些最新进展。 常见的线程是最初为非加密应用程序开发的有趣的算法方法的有用性。 这是ISAAC2010年上半年应邀演讲的扩展版本。 ********************************** 3. 试论威尔配对和泰特配对的计算 在过去的十年中,我们看到了威尔/泰特对在密码学中的几个显著应用。 例如,它们用于某些类椭圆曲线的离散对数问题的约简。 它们也是一些令人兴奋的新密码原语的基本构建块。 在这篇文章中,我们将首先制定一个计算过程,它涉及一类特殊的约数和有理函数。 然后,我们将讨论椭圆曲线上的威尔/泰特对,以及米勒计算对的算法。 在最后一部分,我们将讨论我们对米勒算法的改进和一些实现问题。 ********************************** 4. 腔内冷原子或超导量子比特的超辐射、光子相扩散、贝里相和数压缩态 最近,实验实现了光腔内玻色爱因斯坦凝聚原子与微波电路腔内超导量子比特、量子点、电子自旋的强耦合。 所有这些系统中的强耦合机制都可以用迪克模型来描述。 在这里,我们通过$1/N$膨胀来求解迪克模型来研究腔透射和荧光光谱。 在正常状态下,我们发现集体拉比分裂的$行为与实验数据一致。 在超辐射相位内,我们识别了一个高频模式和一个在有限$N处具有相应贝里相位的紧急量子相位扩散模式$并确定了它们相应的谱权重。 我们还计算了这种量子相位模式的许多显著的实验结果,如其低频、高光谱重量、连续光子平台,光子数压缩特性和光子统计。 我们认为,最近在冷原子和半导体系统中的实验进展应该激励一个新的新兴的量子光学和量子相的跨学科领域,可以被称为“强相关量子光学”。 *********************************** 5. 强相关量子系统的张量积态法 方形晶格上的自旋1/2J1-J2反铁磁海森堡模型因其有趣的量子相变和可能的奇异相而引起了人们的广泛关注。 由于其沮丧的性质,大规模低温量子蒙特卡罗研究被禁止。 另一方面,张量网络变分波函数假设很好地描述了强相关量子多体系统,张量网络方法由于其变分性质而不存在负号问题。 因此,我们通过张量网络方法探索了该模型的基态相图。 利用最近提出的张量网络状态集群更新算法,我们能够访问虚拟键维D高达9的张量网络基态。 我们观察到一个二阶量子相变从反铁磁有序相到顺磁无序相在临界点J2_c=0.47。 顺磁无序相位保持了哈密顿量的所有对称性,没有任何局部阶数。 这种无序顺磁状态的自旋液体性质是非常可能的。 我们进一步研究了无序顺磁相的拓扑纠缠熵,发现它属于Z2拓扑类.. ************************************ 6. 黎曼流形上的特征函数和顶点算子代数的表示 物理学家对非线性西格玛模型的猜想是过去两三年来许多几何作品最有影响的灵感和动机之一。 不幸的是,非线性西格玛模型仍然没有在数学上构造。 在我的演讲中,我将讨论程序中的第一步,利用黎曼几何和顶点算子代数的表示理论,在数学上构造这些模型。 给定一个黎曼流形M,对于半径小于或等于点处注入半径的M上点为中心的开球,利用Oepn球中点的法线坐标,我们构造了一个由光滑函数空间生成的海森堡代数的模块,例如在光滑函数上,L(0)充当Laplacian。 利用这些模块、海森堡代数的某些子代数的模块和胶合方法,构造了由光滑函数的sheaf生成的顶点算子代数的一个sheaf的弱模块。 特别是,我们构造了一个L(0)-Semisimple下界广义模块,用于由Laplacian在M上的特征函数生成的M上全局截面的顶点算子代数。 ************************************ 7. 列文-文模型和张量类别 我将介绍张量范畴的数学理论及其在Levin-Wen模型中的应用,该模型描述了一大系列非螺旋拓扑阶。 如我们所知,当系统采用某种对称性时,群的表示理论可以用来对相位、激发或粒子进行分类。 然而,我们发现在某些情况下,对称性是不够的,例如拓扑顺序,其中相关的数学结构是张量类别。我将首先从一般范畴理论的一些基本内容开始。 然后,我将介绍张量类别和模块类别的概念。 有很多结构可以添加到张量类别。 我将介绍其中一些与我们相关的,如单元性、半简单性、刚性、枢轴结构和球形结构。 这些结构使我们能够用有向标记图来表示张量类别,这也出现在Levin-Wen模型中。 表征理论给出了一种描述莱文-文模型中激励的方法.. 我们不直接处理激励,而是研究激励的“边界”。 对于张量范畴结构,这些“边界”构成代数和代数上的模块。 我们可以通过研究这些代数来分类激发。 这也对应于张量类别及其模块类别的结构。 *********************************** 8. 动态结构因子(DSF)在一维排斥玻色子气体中的大动量大频率行为-一系列普遍关系的介绍和OPE方法在冷原子物理中的应用 最近(从2008年到现在),在原子量子气中发现了一系列普遍关系,其中相互作用范围远小于系统中任何其他长度尺度。 这些关系在多体波函数的短程(或高能)相关性与系统的宏观性质之间建立了桥梁。 这种关系的原始证明涉及到新的数学方法和由Shinatan首先引入的广义函数。 随后,介绍了另一种涉及OPE(算子产品扩展)理论和标准重整化过程的推导。 结果表明,OPE方法是一个非常合适的框架,可以研究具有接触相互作用的系统的短程特性,该方法易于推广,从而给出额外的普遍关系。 在这篇演讲中,我将简要介绍OPE方法在冷原子物理中的应用,并回顾几种重要的普遍关系。 然后我将介绍我最近的工作,与专业合作。 谭,在相关领域的一维系统。 将OPE方法与几体贝斯-安萨茨波函数相结合,得到了DSF在高频极限下的一般渐近形式。 ************************************ 9. 来自肮脏的美丽-最近安德森本土化的挑战 在过去的十五年中,光学系统和超冷原子气体实验中达到了前所未有的控制程度,引发了安德森定位研究的“无声革命”。 在这篇演讲的第一部分,我将简要回顾本土化的最新情况。 在本次演讲的第二部分,我将重点介绍这一领域最近的挑战----开放媒体的本地化。 我将介绍最近的实验和理论研究,表明波干扰与边界处的波能量泄漏之间的相互作用可能导致非常丰富的局域物理。 然后,我将在开放媒体中引入一种非常规的扩散现象-局部扩散现象。 ************************************ 10. 真空的命运 真空本质上是由没有已知或相信存在的东西来定义的。 因此,真空的概念及其可能存在一直与物理学中的基本问题有关。 我们将描述从十六世纪到二十一世纪初的思想演变,从讨论坠落的物体到暗物质和暗能量。 ************************************** 11. 斜密码分析,与AES的应用 由于Rijndel被选为高级加密标准(AES),并成为全球加密标准,因此改进对128位密钥变体的7轮攻击或对256位密钥变体的8轮攻击被认为是十多年来分组密码密码分析中最困难的挑战之一。 我们提出了一种新的方法来恢复密钥使用所谓的双轴。 这使我们能够首次获得更多回合的结果,但相对于蛮力搜索的优势可能变小。 与AES版本上的大多数快捷攻击设置不同,我们不需要任何相关键。 我们的方法在很大程度上得到了实际的验证,但它的充分实现需要巨大的计算资源。 *************************************** 12. Gutz willer预测S=1自旋链的费米理论中的波函数 基于自旋的费米子平均场理论,我们开发了S=1系统BCS型平均场态的Gutz willer投影方法。 通过变分蒙特卡罗(VMC)方法,我们可以利用投影波函数来逼近基态。 我们研究了S=1双线性-二次模型$H=sum_i Jmathbf S_icdotmathbf S_{i+1}K(mathbf S_icdotmathbf S_{i+1})2,发现当存在间隙时,优化的投影波函数非常接近基态。 平均场状态的拓扑结构是重要的。 投影后,拓扑非平凡态(弱配对态)对应于Haldane相,而拓扑平凡态(强配对态)则落在二聚相。 从VMC得到的过渡点非常接近精确结果.. 弱/强配对与Haldane/二聚相之间的对应关系可以用平均场基态周围的Z2规范Uctuations来解释。 **************************************** 13. 磁天子晶体中的自旋转移力矩和突现电动力学 一个Skyrmion晶体-一个拓扑稳定的磁旋转晶格-可以在有限磁场范围内稳定在手性磁体中,到目前为止,它已经在MnSi、FeGe或Fe_{1−x}Co_xSi等几种金属化合物中被识别出来。 这种磁天子有效地耦合到自旋电流,导致在低电流密度为10阶^6A/m^2阶的块体材料中可观察到的自旋现象。 首先,自旋电流可以诱导Skyrmion晶格[1]的有限空间旋转,这可以理解为角动量的双转移:除了通常的自旋转移扭矩外,角动量从磁性织构转移到离子晶格,产生机械扭矩,导致Skyrmion晶格旋转。 第二,一个移动的天球晶格导致人工电场和磁场作用于电子,最近通过霍尔效应测量[2]检测到。 当电子自旋不断适应天旋结构时,它的轨道运动经历了每个天旋一个通量量子的人工磁场。 如果施加的电流超过一个阈值,则Skyrmions的脱粘会产生一个移动的磁质构,通过Farady的感应定律诱导人工电场。 由此产生的新的人工电动力学有望成为一个有趣的游乐场新的自旋现象。 ***************************************** 14. 零相关线性密码分析与降低数据复杂性 零相关线性密码分析是一种新的分组密码密钥恢复技术。 它是基于线性近似,概率正好为1/2(对应于零相关)。 一些分组密码在相当多的回合中对每个密钥具有多个线性近似,相关为零。 零相关线性密码分析是线性密码分析领域中不可能的差分密码分析的对应物,尽管有许多技术上的区别,有时会导致更强的攻击。 我们提出了一种使用高数量的零相关线性近似来显著降低数据复杂度的统计技术。 我们还确定了14轮和15轮TEA和XTEA的零相关线性近似。 这导致了21轮TEA和25轮XTEA的关键恢复攻击,同时要求的数据比完整的代码本少。 在单密码设置中,这些是结构攻击,打破了两个密码的最高回合数。 ***************************************** 15. 由三个球面谐波多项式乘积构造的旋转不变量 H.Weyl(1946)建立了旋转不变量的重要结构定理。 比登哈恩和洛克在他们著名的量子物理中关于角矩的数学百科全书(1981)中对一般定理最重要的情况(n=3)进行了一些详细的研究。 然而,他们在书中指出:``不幸的是,在文献中没有给出一般系数的表达式,人们不得不从定义中计算出这些不变多项式”。 我们已经完全解决了Biedenhann和Louck提出的问题,并在本文中给出了系数的一般和显式表达式。 ******************************************** 16. 拉金-奥夫金尼科夫态的波动、稳定性和相变:量子液晶 在极化Feshbach-共振原子气体的激励下,我将讨论假定的Larkin-Ovchinnikov(LO)状态下低能波动的性质。 由于基本的旋转和平移对称性是自发破坏的,这种无间隙超流体是一种量子包晶液晶,它表现出比传统超流体更强的波动,因此需要对其戈德斯通模式进行完全非线性的描述。 因此,在非零温度下,LO超流体是一个代数相,即使在3D中也是如此。 它表现出半整涡失调缺陷,其解绕导致过渡到超流向列相和其他相。 在非零温度下的2d中,LO状态总是不稳定于电荷-4(配对Cooper对)向列型超流体。 我期望这种超流体液晶现象学能够在非平衡共振费米气体中实现。 ********************************************* 17. P波超流性 我将讨论与p波超流性相关的新物理,由p波Feshbach共振驱动,例如在Rb85-Rb87玻色子混合物和K40费米气体中观察到的。 ***************************************** 18. 液晶橡胶的奇异弹性 在对相和相变进行了全面的介绍之后,我将讨论一种迷人的液晶橡胶现象学,这是一种外来材料,是传统液晶和橡胶的汞合金。 虽然固体在许多方面,由于它的取向和弹性自由度之间的相互作用,它的一些弹性常数在这个_solid_的液晶中完全消失。 因此,在某些方面,这种固体的行为就像液体。 例如,在向列相状态下,在几乎零应力下,它可以向某些方向拉伸多达400%。 我将讨论这种矛盾材料的奇异行为的一些理论基础,这是相当基本和应用的兴趣。 ****************************************** 19. 超冷原子在光学晶格中量子临界性的观察 当多体系统接近连续相变时,出现临界现象。 特别是,量子临界性预测了系统在低温下由量子波动驱动的跃迁附近的普遍性质,为理解从亚原子粒子到宇宙黑洞的许多不同的自然系统提供了关键。 超冷原子提供了一个干净的系统来测试这些预测的普遍性质。 在这篇演讲中,我将分享我们最近对光学晶格中二维玻色气体的量子临界性的观察。 在原位密度测量的基础上,我们观察了低温状态方程的标度行为,定位了量子临界点,并约束了临界指数。 我们的方法对识别一般量子相变和研究临界系统是如何随着时间的推移而发展有希望。 此外,我将简要讨论我们最近升级的成像设置,以更高的分辨率与定制设计的显微镜目标。 ***************************************** 20. 经典波的安德森定位前沿 微波和扩散和局域波光传播的测量我将讨论在测量稳态和脉冲微波和光学传播在随机介质中的统计方面的挑战,以及使详细和准确的测量成为可能的因素的惊人汇合。 这些测量给出了统计等价样本的随机集合的统计量以及单个样本中的统计量。 单个样本中的统计对于成像、聚焦和增强随机介质中的传输至关重要,在生物医学成像和电信中具有潜在的应用前景。 我们的发现的本质是在一系列的关系之间的定位参数,封装了波传播的不同方面。 包括强度的平均值,波动和相关性,总传输和电导,传输特征值的参与数以及随机介质的模式宽度和间距的比值.. 最后,我将讨论在随机样本中寻找能量分布的努力,并将其与透射辐射的特性联系起来。 ***************************************** 21. 开放媒体中的局部波传输 自50多年前P.W.安德森首次提出随机介质中的波定位概念以来,安德森定位已成为凝聚态物理中的一个重要现象。 这种现象普遍存在于随机环境中的波传播中,包括脏金属中的电子、随机介质中的经典波和随机势中的物质波。 在本文的第一部分,将简要介绍安德森的本土化。 特别是,一些重要的概念和理论将被提及和讨论,如弱局部化(WL)效应,这是引起波局部化的最重要的波干扰效应,以及自洽局部化理论(SCLT).. 在2000年,SCLT被推广到开放介质中的随机系统,并引入了位置相关扩散系数的概念。 在我的谈话的第二部分,我们最近对局域波在一维和准一维开放介质中的静态和动态传输的一些研究结果将被介绍。 特别是,具有位置相关扩散系数的SCLT无法描述长时间的动态微波传输测量。 这有力地表明了共振传输在局域样品中波的传输中的重要性。 讨论了一种只包含孤立谐振传输而忽略项链状态的动态单参数缩放模型。 在静态极限下,将给出用超对称场理论得到的解析结果。 结果表明,该理论能够捕获所有罕见的共振传输,并给出了一种新的局部扩散系数标度行为。 ******************************************* 22. 改进对多重加密的攻击 多个加密方案使用具有独立n位密钥的基本加密方案k次,以增强其安全性.. 这种方案的典型例子是双DES和三DES,其密钥分别为2*56和3*56位长。 多年来,对这种方案的安全性进行了广泛的研究,但对它们的所有已知攻击(保证成功)都需要时间T和内存M,其乘积至少为2^{kn}。 在这篇演讲中,我将介绍打破这一界限的多个加密的第一次攻击,例如对k=7个连续加密的攻击,这些加密需要时间为T=2^{4n}和M=2^n的内存,其乘积仅为TM2^{5n}而不是预期的TM2^{7n}。 这些攻击使用了一种新的技术,称为Dissection,它可以用来解决许多与密码学无关的组合搜索问题(如背包问题),其算法比以前最好的技术更有效。 ****************************************** 23. 寻找电子圆度低于10^-28厘米. 电子的电偶极矩(eEDM)将对超出标准模型的粒子物理敏感.. 我们利用分子键内发现的极端电场,进行了提高电火花加工电流极限的实验。 我将概述我们在JILA的实验的原理和实现。 ****************************************** 24. 特殊超导和冷原子 最非常规的超导体:Sr2RuO4。 十八年后,我们知道什么? 在钙钛矿Sr2RuO4中发现超导电性18年后,关于超导有序参数性质的基本问题仍然存在。 在超导电性被发现后,理论上就认识到它可能是一种手性对波态,即超流氦3的A相的固态类似物。 如果是这样的话,这将是迄今为止唯一已知的电子系统中这种奇异的时间反转对称性破坏状态的例子。 然而,经过十多年半的激烈实验努力,Sr2Ru04是否是手性p波的问题仍然缺乏明确的答案。 在这篇演讲中,我将回顾其中的一些实验和理论,强调来自Kerr旋转测量的时间反转对称性破坏的特征,以及SQUID显微镜实验所暗示的拓扑时间反转对称性破坏边缘电流的似乎缺乏。 我将认为,Sr2RuO4的多波段性质及其大的自旋轨道耦合可能在解释这些实验中起着核心作用。 *************************************** 25. 莫特反铁磁体单孔的自定位 安德森局域化是现代凝聚态物理的一个基本概念,是量子抑制由于无序而产生的载流子扩散。 在这里,我将谈论一种完全违背这种共同智慧的新的本土化现象。 引人注目的是,它纯粹是强烈的相互作用起源,在没有疾病的帮助下发生。 具体来说,通过组合数值(密度矩阵重整化群)方法和解析分析,我们表明,在量子反铁磁阶梯中注入的单个空穴通常是自定位的,即使系统尊重平移对称性。 定位长度随腿数的增加而单调减小,表明在二维极限下具有较强的自定位能力。 我们发现掺杂电荷与量子自旋背景之间的特殊耦合导致了不同空穴路径之间的量子干涉。 后者使洞穴的流动运动停止,这是一个现象学的类比安德森定位。 我们的发现与掺杂孔的准粒子图像的共同信念相反,并为轻掺杂Mott绝缘子揭示了一种全新的范式。 **************************************** 26. 强相互作用费米子的粘度 在强相互作用的量子流体中的传输在不同的物理领域-凝聚态物质、黑洞和弦理论、夸克-胶子等离子体和冷原子-中有着很大的兴趣,乍一看,它们似乎没有什么共同之处。 在这篇演讲中,我将重点讨论超冷费米气体的体积和剪切粘度,对此,最可控的实验是可能的。 我将首先讨论运输和热力学之间的连接在整个BCS-BEC交叉使用精确和规则[1]。 我将描述三维中强相互作用的酉态的含义,其中尺度不变性导致特别有趣的预测。 然后,我将讨论最近的结果[2],这将深入了解为什么在2D费米系统上的实验似乎在低能下表现出尺度不变性。 ****************************************** 27. 博斯尼克量子大厅 实现玻色子量子霍尔态一直是冷原子研究的一个长期目标。 由于最近在美国宣布的一些积极的研究举措,这种搜索现在进一步加强。 在这篇演讲中,我指出了一种自然和实用的方法来产生玻色子劳克林州和普法芬州。 这种方法是一种新版本的“BEC-BCS交叉”,被16世纪发现的一些数学识别所捕获。 如果时间允许,我还将介绍美国的新研究倡议,这些倡议积极地将凝聚物质和冷原子社区结合起来,以追求一些雄心勃勃的目标。 ******************************************* 28. 拓扑超导体和超流体的研究进展 研究托马利亚纳零界态(MZBS)的拓扑超导体和超流体已发展成为凝聚态物理学的一个迅速发展的分支,这一分支既受外来基本物理学的追求,也受容错拓扑量子计算(TQC)的应用的驱动。 在这篇演讲中,我将概述拓扑超导体和超流体的理论和实验结果,重点是一维和二维系统。 对于二维系统,Majorana零模存在于涡核中,对于一维系统,这种零模存在于边界中。 这次谈话分为三个部分。 第一部分将回顾拓扑超导体和超流体的基本原理。 然后,我将重点介绍最近在固体系统中观察Majorana零模式的进展。 最后,我将介绍一些关于冷原子系统中拓扑超流体的最新研究。 ****************************************** 29. 重整化组:导言 重整化小组在20世纪物理学中发挥了至关重要的作用 在两个明显无关的领域:基本相互作用理论 在微观尺度和连续宏观理论 相变。 在前一个框架中,这是由于 重整化的必要性,以取消无限,出现在一个简单的 量子场理论的解释,以及当时的自由 定义重整化理论在不同动量下的参数 天平。 在相变的统计物理中,更普遍的重整化 组,基于在短距离程度上的递归平均 自由,后来被引入来解释连续的普遍性质 相变。 量子场理论的重整化群现在被理解为 高斯不动点某些邻域中一般重整化群的渐近形式。 因此,在统计领域理论的框架下进行相关的简单 相变,我们首先解释扰动重整化群。 然后,我们回顾一些重要的应用程序,如缩放定律的证明 以及热力学函数奇异性的确定 过渡时期。 然后,我们将结果推广到临界动力学。 最后,我们描述了一般的重整化群,也称为泛函 或者精确的重整化组。 ************************************** 30. 低维动量守恒晶格中的热导 在过去的几十年里,广泛的分析、数值和实验研究强烈地表明,在低维(即一维和二维)动量守恒系统中,热传导行为不遵循傅立叶定律,可分为几个通用类[1,2]。 然而,最近我们发现,在低维晶格中,不对称的粒子间相互作用通常会导致正常的热传导[3,4];同时,在没有不对称粒子间相互作用的晶格中,异常的热传导行为可以明显地不同于已知的普遍类[5]。 这些结果表明,重要的是要澄清在多大程度上,传统的水动力理论可以应用于低维热传导问题,并有必要考虑潜在的动力机制。 ********************************************* 31. 四元数分析兰道水平在3D和4D 通常的2D Landau能级产生于电子在磁场中的回旋运动,这在很大程度上依赖于平面几何。 最低朗道波函数的复杂解析性对于分数量子霍尔态的研究至关重要。 另一方面,目前对三维拓扑绝缘子的研究主要局限于晶格系统。 复杂的布洛赫波函数和色散能谱是分数阶高维拓扑态研究的障碍。 我们想回到Landau水平的高维拓扑态,因为它们是明确和优雅的。 我们确定了它们与四元数的联系,四元数是汉密尔顿在1843年发现的第一个非交换除法代数,其解析性质是由Feuter开发的。 通过将自旋1/2费米子与SU(2)Aharanov-Casher势耦合,在连续体中构造了简单的哈密顿量。 它们表现出平坦的SU(2)Landau能级,其中轨道角动量和自旋与固定的螺旋度耦合。 最低Landau级波函数满足四元数分析的Cauchy-Riemann-Fueter条件。 每个Landau水平贡献一个分支的无隙螺旋Dirac模的表面光谱。 这些结果也被推广到狄拉克电子,这可以看作是二维狄拉克兰道能级问题的四元数推广。 狄拉克费米子的齐罗斯·兰道能级是半铁离子Jackiw-Rebbi模的一个分支,在所有高维角动量量子数中退化。 我们还研究了Landau型量规中SU(2)Landau能级的4D量子霍尔效应,它表现出量子化的非线性电磁响应作为空间分离的手性异常。 我们期望兰道能级的四元数分析性质和光谱平坦度将进一步促进高维分数拓扑态的研究。 ******************************************* 32. 具有强自旋轨道耦合的量子点接触空穴的自旋极化传输 我们研究了以Ga为二维空穴气体制备的量子点接触(QPC)。 我们表明,磁聚焦实验的几个令人惊讶的方面可以理解为在最低的两个自旋子带的有限动量下存在一个交叉点。 交叉点来源于非对称量子阱中空穴的强二维拉什巴自旋轨道相互作用,对动量具有非线性(立方)依赖性。 我们还讨论了平行于通道的磁场,或QPC侧电位的不对称,如何消除交叉点的简并性。 这些特征使我们能够解释由QPC滤波的自旋极化的反常迹象,以及自旋极化对磁场的惊人的非单调依赖性。 控制自旋分裂的大小,为反演自旋极化信号提供了一种新的机制。 ******************************************** 33. 拓扑绝缘子量子反常霍尔效应的实验观察 反常霍尔效应是130多年前在铁磁材料中发现的,其中即使在没有外部磁场的情况下也存在霍尔电阻。 自20世纪80年代发现量子霍尔效应以来,反常霍尔效应的量子化版本引起了人们的广泛兴趣。 几年前,有人提出量子反常霍尔效应可能发生在磁掺杂拓扑绝缘子中,但实验实现一直难以实现.. 在这篇文章中,我们将报告用分子束外延生长的拓扑绝缘体薄膜的输运研究。 主要的焦点将集中在电子结构、磁序和体带拓扑的调谐上,这导致了量子反常霍尔效应的实验实现,即零磁场中的量子霍尔效应。 ********************************************* 34. 伽罗瓦理论 线性和二次方程的解是所有古代文明都知道的.. 然而,解三次方程和四次方程的方法直到发现 文艺复兴。 法国数学家越田和拉格朗日对理论做出了开创性贡献 代数方程。 当时几乎所有的著名数学家都试图解决这个问题 五次方程,但都失败了。 19世纪初,挪威数学家阿贝尔 意大利数学家鲁菲尼证明了一个一般的五次方程是无法求解的 激进分子。 然而,他们没有给出一个真正的五次方程,不能用自由基求解。 在20世纪20年代,一位年轻的法国数学家埃瓦里斯特·加洛瓦成功而彻底地 解决了类似的问题,奠定了现代代数的基础。 在这篇演讲中,我将简要介绍如何求解三次方程和四次方程 代数方程与排列群的关系。 接下来,我将介绍Galois 用Galois理论证明了五次方程的不可溶性。 ******************************************** 35. 准2D费米气体的高度极化极限 具有短程相互作用的费米原子的超冷气体代表了一个独特的游乐场,用于研究由于维数和相互作用的精细控制而在强相关系统中的配对和有效相互作用。 在这篇演讲中,我将首先回顾最近在该领域的理论和实验进展。 接下来,我将重点讨论准2D费米气体的高极化极限,我将讨论在费米海中浸泡时单个杂质可以形成的准粒子的性质,以及由此产生的基态相图作为质量不平衡的函数。 我将展示如何通过准2D约束移动吸引分支的基态跃迁,以及如何在整个2D到3D交叉过程中定量地描述这一点。 我还将演示如何快速衰减的排斥分支排除流动铁磁性在这个系统。 ******************************************** 36. 二维偶极费米气体 超冷的原子气体提供了一个非常清洁和可控的系统,在其中探索量子多体现象。 到目前为止,重点一直是短程相互作用,因为这些很好地描述了原子在低能极限下的散射。 然而,最近产生的具有电偶极矩的极性分子引起了人们对远距离偶极相互作用的兴趣。 在这篇演讲中,我将研究费米子极性分子的二维气体的相,其中分子偶极矩都是由外部电场排列的。 我将证明,这样的气体可以自发地打破旋转对称性,形成密度波(或条纹相位),以进行足够强的排斥相互作用。 这提供了一个密度波的模型例子,它纯粹是由排斥驱动的,而不是,例如,底层晶格的扭曲。 ****************************************** 37. 三阶段可解晶格气体模型 利用二维(2D)Ising模型的Onsager和Kaufman的辉煌解,李和杨在1952年构造了一个晶格气体模型,其中p-V图中的两相区域是解析已知的。 在本工作中,我们构造了具有三个阶段的双工模型,而不仅仅是两个阶段,并且可以精确地计算p-T图和p-V图中的相位边界。 这些模型有两个子格,在子格中分别有长程有序形式,形成了一种偏序。 ****************************************** 38. 自旋轨道系统中的量子输运 具有强自旋轨道耦合及其输运性质的电子系统是凝聚态物理和相关应用中各个重要领域的核心,从自旋霍尔效应和自旋电子学到拓扑绝缘体和Majorana费米子.. 最近,还有可能产生具有“合成”自旋轨道耦合的原子量子气体(包括玻色子和费米子),实现可调谐冷原子“量子模拟器”,以探索自旋轨道物理和相关的新量子相。 在这篇演讲中,我将在我的实验室中讨论一些实验,研究电子拓扑绝缘体中的量子输运(包括拓扑表面态和拉什巴自旋轨道耦合二维电子气体)以及自旋轨道耦合原子玻色-爱因斯坦凝聚(BEC)。 我将展示如何在这两个系统中产生自旋极化输运和探针自旋动量锁定,并讨论自旋轨道耦合与超导电性或超流性之间可能的相互作用。 ******************************************** 39. 一维非线性量子液体 一维量子流体的传统描述是基于Luttinger液体理论。 在该理论中,组成流体的粒子的真正能量-动量关系被线性关系所取代。 这种简化对理论是至关重要的,放弃它已经证明是困难的。 这次谈话提出了一个突破,使人们能够避开困难。 新理论描述了由具有通用光谱的粒子组成的流体的动态响应。 它适用于一组不同的系统,例如,包括量子线中的电子和一维陷阱中的冷原子气体。 ******************************************* 40. 宇宙学研究粒子物理学 现代宇宙学与粒子物理学密切相关。 不仅我们对宇宙的结构、演化和物质/能量含量的理解依赖于粒子物理、宇宙条件和天文物体,也为粒子物理提供了一个试验台。 将概述这种联系。 ******************************************** 41. 吸积盘的数值模拟:磁控不稳定性之旅 吸积盘在天体物理系统中普遍存在,对于研究广泛的天体的形成和演化具有重要意义。 吸积需要有效的角动量向外传输,最强大的机制是磁控不稳定性(MRI)产生的湍流。 表征MRI湍流的物理性质需要大的磁流体动力学(MHD)模拟。 在过去二十年中,取得了重大进展,但仍有许多悬而未决的问题。 我将回顾基本结果以及MRI数值研究的最新进展,分为三类:无垂直分层的局部模拟、包括垂直分层的局部模拟和全局模拟。 还将简要讨论其他物理学,如非理想的MHD效应与应用于原行星盘。 仿真结果突出了大规模磁通的重要性及其与吸积盘的耦合演化。 *********************************************** 42. 量子统计力学,L系列,阿纳贝尔几何 这一谈话是基于与GuntherCornelissen的联合工作。 我将展示与数字场相关的量子统计力学系统如何提供完全不变量,允许将数字场重建到同构,尽管它们的一些主要组成元素本身(Abelianized Galois组、Dedekindzeta函数和Adeles环)不是完全不变量。 特别是,利用这些量子统计力学方法,我们得到了一个新的纯数理论结果,表明一个数场可以从具有Grossen字符的L-函数的相关族中重建。 ******************************************** 43. 石墨烯样晶格上相关费米子的阶段 石墨烯状晶格尽管缺乏几何挫折感,但由于低维度、低配位和中性点状态密度的增加而增强的波动,为费米子的新阶段提供了一个很有前途的游乐场。 我们在这篇文章中回顾了量子蒙特卡罗模拟中出现的不同阶段,因为它们与单层和双层体系中的结构相互作用、自旋轨道相互作用以及一些N>2种口味。 后一种情况,最初是由理论动机引入的,现在可以用超冷的碱土原子在光学晶格中实现。 ********************************************** 44. 石墨烯的简单物理:类比研究. 在简要介绍石墨烯的物理之后,我们将讨论石墨烯中的电荷输运与光在介质中的传播之间的相似性,并介绍最近关于无序对这些过程的影响的结果。 ************************************************ 45. 拓扑绝缘体中的Dirac与Weyl:输运现象中的Adler-Bell-Jackiw异常 当扰动破坏时间反转对称性或反转对称性时,Dirac金属(无间隙半导体)被认为会转变为Weyl金属。 然而,没有实验证据报道在三维存在Weyl费米子。 在Bi1-xSbx中,利用拓扑相变附近的磁场从拓扑绝缘体到带绝缘体,不仅观察到零磁场(B<0.4T)附近磁导电性中的弱反局域现象,而且只观察到E/B在0.4T以上的上升现象。 弱反定位和“负”磁阻之间的这种“不相容”共存是由于Adler-Bell-Jackiw异常(“拓扑”项)在弱反定位校正的情况下。 ************************************************ 46. 纠缠三角:引力,信息和凝聚物质 这个研讨会的三个主题似乎属于科学研究的遥远领域,但它们实际上是密切相关的。 引力和信息最初是由霍金联系起来的,他理解黑洞携带的信息(熵)表现为地平线区域,并得出结论,黑洞蒸发会导致信息的莫名其妙的丢失。 引力和凝聚物质一起发现了AdS/CFT对应关系,这是引力理论和我们研究临界系统最稳健的形式主义之间的二元性。 信息,或量子纠缠,在凝聚态物理中具有深远的重要性:它被用来区分奇异的物质相,也被用来利用张量网络在晶格设置中模拟临界系统。 在过去的十年中,我们了解到,这些和类似的联系比以前所赞赏的更深。 许多新的相互关系已经被证明和推测,包括纠缠是保持时空不散的粘合剂或时空是张量网络的断言。 在这个研讨会上,我们将试图证明或反驳一些这样的陈述,猜测新的陈述,并学习“它从比特”的真正含义 *********************************************** 47. 二维拓扑阶段的对称分数化 对称性分数化描述了二维拓扑系统中的激励可以在对称性下以分数的方式变换的迷人现象。 例如,在分数量子霍尔系统中,激发可以携带分数电荷,而组成该系统的电子具有电荷。 一个重要的问题是了解在不同类型的拓扑顺序和不同的对称性的情况下,什么是对称分数化(SF)模式是可能的。 最近在对SF模式进行分类方面取得了许多进展,为自旋液体和拓扑绝缘体等系统的强相关实验特征提供了深入的见解。 在这个讲座中,我们回顾了这个主题的最新发展。 首先,结果表明,SF模式需要满足一些简单的一致性条件。 更有趣的是,人们意识到一些看似一致的SF模式实际上是`异常的”,即。 它们不能在严格的二维系统中实现。 我们回顾了为检测这种异常而开发的各种方法。 将这种理解应用于二维自旋液体,可以列举所有潜在的可实现的SF模式,并提出数值和实验探测方法来区分它们。 另一方面,异常SF模式存在于三维系统表面,反映了三维体中的非平凡顺序。 我们回顾了这种例子,其中体态是拓扑绝缘体,拓扑超导体,或有其他对称保护拓扑顺序。 ********************************************** 48. 量子材料的拓扑和挫折 物理学前沿的一个重要主题是发现和理解超出标准教科书分类的物质的新量子阶段。 在过去的十年中,一些新的现实平台家族,如拓扑绝缘体和半金属、铁基超导体、几何受挫磁体以及光学晶格中的超冷原子,已经被实现和广泛研究,这大大提高了我们对所谓的“量子材料”的认识。 拓扑和挫折代表了在这些异国情调的例子中经常遇到的两个新特征。 该讲习班旨在汇集这一广泛领域的积极研究人员。 通过交流和讨论对广泛系统的观察,我们期望这次研讨会将有助于分享关于量子材料的不同观点,并激励进一步的研究。 *********************************************** 49. 寻找大爆炸的指纹 我将描述BICEP/Keck程序,这是一系列基于南极的实验,旨在通过测量宇宙微波背景辐射的B模极化来研究通货膨胀。 BICEP望远镜的特点是紧凑型折射器和全光刻超导极化仪阵列。 2014年3月,BICEP2报告说,在与通货膨胀预测相对应的角度尺度上,B模极化明显过剩。 我将描述这个测量意味着什么,当前前景的不确定性,以及我们将如何跟进Keck和BICEP3,目前和下一个实验的系列。 ****************************************** 50. 光学超晶格中的量子模拟 光学晶格中的超冷原子是研究量子的有前途的候选材料 多体现象。 双色超晶格提供了一个新的工具 方向。 在这篇演讲中,首先,我将概述所做的实验 超级晶格。 然后我将集中讨论最近的两个实验。 我会先报告的 超冷原子强有效磁场的实验实现 拉曼辅助隧穿在光学超晶格中。 我们研究了它的性质 在有效的交错磁场存在下的受挫基态 它的动量分布直接揭示了a的量子回旋轨道 单个原子暴露在磁场中。 在下一个实验中,我将介绍 直接测量Zak相-在绝热过程中获得的Berry相 粒子在布里渊区的运动-对于二聚光学晶格,它 模型聚乙炔。 实验协议由Bloch的组合组成. 振荡和Ramsey干涉测量。 这项工作确立了一种新的一般方法 用于探测光学晶格中Bloch带的拓扑结构。 *********************************************** 51. 重电子材料中的双流体模型和紧急状态 重电子材料为探索提供了一个有用的原型 非常规超导电性和新磁性的潜在机制。 其中包括1979年发现的第一个d波超导体CeCu2Si2。 的. 在过去的十年里,已经看到了许多重要的进展,如新的量子临界 “隐藏”顺序和拓扑近藤绝缘体。 然而,我们仍然没有 经过三十年的研究,令人满意的微观理论。 在这次谈话中,我会的 介绍一个现象学模型,并展示它如何导致戏剧性的变化 我们对实验观测的解释,从而发现了新的 普遍性质。 然后,我将讨论一些最近的进展和a的建议 新的统一框架,可以帮助我们更好地理解重电子物理。 ********************************************************* 52. 量子霍尔效应的拓扑和几何 在这篇演讲中,我将回顾量子的一些拓扑方面 霍尔效应,包括拓扑Chern数,无间隙边激励,间隙 带分数电荷的块状准粒子,分数的,可能是非贝里安的 统计,和非平凡的纠缠光谱。 我还将讨论一些最近的问题 填充因子5/2状态的实验和理论理解 被认为是Moore-Read态或其粒子空穴共轭物。 在第二部分 将解释如何引入一个具有相同的波函数家族 拓扑特征,但具有不同的几何信息,编码在 所谓的指导中心度量,这是由Haldane[Phys]提出的.. Rev. 莱特。 107,116801(2011)]用于具有各向异性质量或相互作用的量子霍尔系统。 导向中心度量的量化和各向异性的分解 将呈现FQH状态。 ********************************************** 53. 新的多体体系中一维冷气体的两个例子 冷原子研究在设计系统到量子的方向上蓬勃发展 模拟凝聚态物理中的重要模型。 不过,我会的 专注于另一个不同的,令人兴奋的推力,即探索一些独特的方面 冷原子系统。 其中一个例子是费什巴赫的一维费米气 调谐强相互作用和大自旋种群不平衡。 另一个系统是 导出了在不等奇偶轨道的两腿阶梯上相互作用的费米子 从实验上实现的双井格通过降维和IS 找到拓扑。 ***************************************** 54. 在光激发下,反铁磁自旋有序状态下的玻璃状动力学和尺寸交叉 电荷、轨道和自旋的纳米级电子有序通常在强中观察到 相关的电子系统和它们是重要的紧急材料特性的基础。 暴露 它们在相变过程中的动态是一个重要的科学挑战。 极右翼 由自由电子激光和同步光源产生的超短X射线脉冲提供 利用激光泵研究电子有序的动态演化的新机会 超快X射线探针技术。 在这里,我将介绍我们最近关于动态的结果 反铁磁自旋顺序跨越光诱导相变在一个巨大的 采用超快时间分辨谐振软X射线的磁阻锰矿Pr0.7Ca0.3MnO3 散射光谱。 在“熔化”过程中,我们观察到与之相关的两个时间尺度 电子和晶格相互作用。 然而,复苏过程显示出异国情调 不能用电子或晶格驱动机制来解释的行为。 取而代之的是复苏 在自旋有序,测量了近12年的时间(70ps到几十秒),表现出a 拉伸指数行为,这是玻璃状系统的标志。 此外,一个维度 从低泵注量的1D到高泵注量的3D有效相互作用的交叉是 观察到,表明自旋有序和轨道有序是短暂解耦的。 a 提出了与所有实验观测结果一致的微观图像,并讨论了自旋顺序在相变中的作用。 **************************************** 55. 相关电子系统中物质的拓扑状态 物质的拓扑状态受哈密顿量的非平凡拓扑保护。 不同的国家 拓扑要么是由真实空间中的无隙边态桥接的,要么是参数空间中的量子相变 在过渡点有无间隙激励。 非平凡拓扑要么是裸带结构的继承 (如拓扑绝缘体),或由电子之间的强相关自发产生。 关于后者 我们将集中精力在这次谈话中。 我们同时考虑时间反转对称破断(T-破断)和不变(T-不变). 各州。 1)由于自发相是一种低能现象,但有效的相互作用是从 在较高的能量尺度上,通过虚拟激励进行重整化,我们简要讨论了一种有效的函数重整化 分组方法来处理能量尺度的层次结构,并在平等的基础上处理可变相位。 2)我们展示了 掺杂石墨烯(在范霍夫填充附近)是TRS断裂态的候选材料,如手性SDW和手性d+id‘ 超导状态。 前者导致量子化反常霍尔效应,后者导致量子化热霍尔. 导电性。 我们表明,类似的情况发生在卡戈姆晶格在范霍夫填充。 此外,还有 几何挫折更丰富的阶段出现在Kagome晶格中。 3)我们证明了接近范霍夫奇点, 以及小Q口袋间散射是铁磁类自旋波动的有效机制.. 这就是线索 去简并p波配对通道。 简并很容易被一个弱的自旋轨道耦合所破坏,导致 到T不变拓扑超导相。 按带结构,正常状态必须有2*(2n+1)自旋分裂 费米口袋(包围T不变矩a),以具有强的T不变拓扑超导体。 的. 这种超导体的边缘状态是Majorana费米子。 讨论了有前途材料的前景。 ************************************** 56. 从多个标题看拉什巴相关现象:从多个标题看拉什巴相关现象 轨道透视 在过去的几年里,我一直在发展一个更现实的拉什巴图片 基于多轨道能带结构思想的效果。 我希望这一主动行动是及时的 在TTEheSeseSeNSETT在帽子AAGG吃ReatDea交易OofEeotsfforts是专门致力于苏aceRfacePpeoEAHenomena在BOT两者 拓扑和非拓扑材料系统和各种界面结构。 我会的 试图提供论点,多轨道图片是一个必不可少的成分 对Rashba相互作用的总体微观理解 系统。 即使在没有实质性自旋轨道相互作用的情况下,即。 形成的乐队 通过光元素,我将证明一个类似的自旋Rashba效应正在发生, 被称为轨道拉什巴效应。 实验将检测轨道拉什巴效应 讨论过。 将介绍轨道Rashba思想的几种应用 与自旋转移扭矩动力学的连接,以及近藤效应,假设是 发生在超薄薄膜材料中。 ***************************************** 57. 三带Luttinger液体的不稳定性:重整化组标题:三带Luttinger液体的不稳定性:重整化组 分析并可能应用于K2Cr3As3 被最近发现的具有D3h晶格的准一维超导体K2Cr3As3所激发 对称,我们研究了一次一次的维度thhree-orbilbitalHubbdbardmodldelswiHithgenericellectron RepuliLsive 由眶内排斥U、眶间排斥U‘和Hund‘耦合J描述的相互作用。 从密度泛函理论计算中提取出三个原子轨道中的两个 简并和第三个是非简并的,并且假定该系统处于不适应状态 填充填充。 在玻色化玻色化的帮助下,我们在正常的正常状态下,我们有通常的三带带LuttingerLuttinger液体。 可能的电荷密度波(CDW)、自旋密度波(SDW)和超导不稳定性 用单环重整化组分析。 基态取决于比率J/U。 为了那个 物理相关参数区域,0 00
当1/3
参数区域J/U>1/2。 ******************************************* 58. 绝缘结构中的量子磁体在受到a时被证明是显著的系统. 强磁场。 除了它们自己的内在兴趣之外,它们还可以映射到流动量子模型系统上 粒子。 这使得它们可以作为量子模拟器来研究其性质 相互作用的硬核玻色子。 特别是,我将重点讨论最近的两个阶梯化合物,其中a 数值研究和分析研究的结合使得动力学得到了充分的结果 相关函数。 我将回顾这方面最近的结果,特别是一些实验和 相应的现象理论,如玻色-爱因斯坦凝聚和Tomonaga-Luttinger 液体,如中子,核磁共振和ESR。 我将讨论这一领域最近取得的成功以及一些悬而未决的问题 这些化合物提供的观点,如研究维度交叉的可能性, 紊乱效应等 ******************************* 59. 量子自旋作为量子模拟器 绝缘结构中的量子磁体在受到a时被证明是显著的系统. 强磁场。 除了它们自己的内在兴趣之外,它们还可以映射到流动量子模型系统上 粒子。 这使得它们可以作为量子模拟器来研究其性质 相互作用的硬核玻色子。 特别是,我将重点讨论最近的两个阶梯化合物,其中a 数值研究和分析研究的结合使得动力学得到了充分的结果 相关函数。 我将回顾这方面最近的结果,特别是一些实验和 相应的现象理论,如玻色-爱因斯坦凝聚和Tomonaga-Luttinger 液体,如中子,核磁共振和ESR。 我将讨论这一领域最近取得的成功以及一些悬而未决的问题 这些化合物提供的观点,如研究维度交叉的可能性, 紊乱效应等 ************************************** 60. 通过流不稳定形成行星 公里尺度的月子形成是最困难的阶段之一 围绕年轻恒星形成行星的过程。 它面临着几个专业 障碍。 直接粉尘通过混凝生长是有限的,高达毫米至厘米的大小,由于 碰撞时低效的粘着、弹跳和碎裂。 即使尘土飞扬 设法生长超过厘米的大小,他们不断失去角动量的他们 周围的气体由于恒定的头部风,导致快速轨道衰减到恒星。 规避这些障碍的一个有希望的机制是流 不稳定,其中固体积极参与尘埃-气体动力学 集中自己到高密度,导致直接重力崩溃和 月子的形成。 我将回顾我们目前对流不稳定和平面的理解 形成。 具体来说,不稳定是如何运作的,在什么条件下它驱动 固体材料浓度强,初始质量函数的产生 行星,及其与湍流气体的相互作用将被研究。 ********************************************* 61. AGB二进制文件中的风传质 在AGB二元系统中,风的传质是很难理解的,尽管它在低质量中很重要 二元进化。 许多可观测的物体,如行星星云和碳增强金属贫星,如果我们有一个真实的风质量转移图片,可以更好地理解。 风团 转移,如果导致高吸积率,也会导致二进制的合并。 为了说明 风传质过程中,我们研究了由渐近支(AGB)星和伴星组成的二元体系。 我们进行三维辐射-流体力学(RHD). 模拟通过风切变-溢流(WRLOF)和传递质量的AGB二进制文件 邦迪-霍伊尔-利尔顿(BHL)吸积。 我们的三维RHD模型通过在自适应球面坐标下的射线追踪方法来解决辐射传输.. 我们还考虑了光学薄的冷却 通过求解Saha方程,得到HII、HI、H2、CO和H2O。 仿真结果表明,该算法具有一定的循环性 磁盘或螺旋结构流出可以在二进制系统的不同配置中找到。 吸积盘可以形成周围的同伴。 我们将讨论潜在的重要性 气体在AGB二进制文件演化中的化学和相变。 ********************************************* 62. 基于Majorana零模式的拓扑保护量子计算:理论视角 拓扑材料提供了一种保护,防止在硬件水平上使用退相干 紧急的非贝里安人。 最简单的非阿贝利安顿涉及一个缺陷,绑定 一个Majorana零能模式预测会在某些超导中非常自然地出现 系统。 我将首先回顾最近的进展,并讨论Majorana搜索的挑战。 然后,我将讨论一个短期问题:什么是最简单的方法来揭示连贯 Majorana设备的签名和测量量子位寿命? 为了回答这个问题,我们 提出了一种在Majorana库仑封锁装置中的简单输运测量方法。 最后,我 将讨论一般拓扑量子中的一种严重的误差-双差误差 计算和Majorana量位。 暗黑错误只是作为幂律函数消失的时候 增加编织操作时间。 这种幂律行为可以洗掉优点 拓扑量子计算。 我们找到了一个克服这个严重问题的方案。 ************************************** 63. 二项式的实验量子纠错. 玻色密码 量子纠错(QEC)是一种实用的量子计算机所必需的 量子系统与不受控制环境的必然耦合。 a 基于测量的QEC需要在不干扰的情况下快速提取误差综合征 存储信息和快速实时反馈控制错误更正。 编码 用于QEC的微波腔中光子态的量子信息吸引了很多 因为它的硬件效率而引起兴趣。 这个方案受益于无限 维Hilbert空间的谐波振荡器用于冗余信息编码和 只有一个错误综合征需要监测。 在这次谈话中,我将描述我们的情况 电路中二项玻色子码重复QEC的实验实现 量子电动力学体系结构和对逻辑量子位[1]的完全控制。 的. 演示的二项式玻色子码有望实现QEC增强精度. 测量,也可以进一步探索容错量子计算。 为这项工作开发的量子反馈控制技术也提供了新的. 开放量子系统控制和测量的前景。 ************************************** 64. 有效自由能的非平衡控制 沮丧的磁铁中的景观 几何上受挫的磁铁通常会意外地退化 零温度下的基态。 在低温下,热波动上升 偶然简并,倾向于以最大值稳定基态 熵。 这种被称为“无序有序”的现象突出了这一点 在受挫磁体中,波动对自由能景观的贡献。 在这篇演讲中,我展示了一个人可以在非平衡的环境中控制这样的自由能景观。 在一个具有进动动力学的受挫磁铁中 系统在简并基态流形内的慢漂移运动是 由流形中的快速模式控制。 刺激这些快速模式 产生一个可调谐的有效自由能景观,最小值位于 基态流形的热力学不稳定部分。 i 在焦绿石XY反铁磁体上证明了这一现象,其中a 磁场脉冲足以控制有效自由能 非平衡的景观。 ********************************** 65. 广义Lieb-Schultz-Mattis约束对量子磁体相态的影响 具有大量自旋的量子磁性系统往往能够产生一个伟大的 在零温度下的各种有趣的阶段。 然而,存在着根本的制约因素 量子磁体在微观晶格中编码的紫外数据中的红外行为 旋转。 作为第一个也是最著名的例子,Lieb-Schultz-Mattis(LSM)约束. 禁止在某些具有SU(2)自旋旋转和 晶格平移对称性。 作为一个重要的实验结果,它使 奇异相的确认,如量子自旋液体,其本征性质往往很难 探针直接,通过检查没有自发对称断裂,即 更容易通过标准光谱测量。 在这次谈话中,我们将提出一个新的 LSM约束的拓扑透视。 我们将展示LSM约束是如何与 对称保护拓扑态表面模式的约束。 利用这种关系,我们 将讨论包含不同空间的LSM约束的一大类推广 群(包括平移和点群对称性)和不同的自旋对称性。 的. 与原始约束相比,这种广义LSM约束的适用性范围大大扩展 版本。 我们还将讨论广义LSM约束如何在量子磁体中强制执行连续相变的“奇异性”。 ********************************** 66. 机器学习满足量子物理. 最近,机器学习/人工智能引起了不同方面的巨大兴趣 社区。 在这篇演讲中,我将简要介绍量子机器的一个新兴领域 学习/人工智能-一个跨学科的领域,探索之间的相互作用 量子物理和机器学习/人工智能。 一方面,我会谈谈 几种量子算法,保证了机器学习任务的指数速度。 开始 另一方面,我将展示机器学习的想法和技术如何帮助解决 量子领域的挑战性问题。 ********************************** 67. 量子磁体的奇异自旋激发 量子自旋液体(QSLs)代表了一种新的物质状态,其中没有自发对称性 断裂和旋转保持在液体状态,即使在绝对零温度。 他们坚持 量子计算和通信的巨大潜力。 此外,人们认为 了解QSL可能有助于解决高温超导电性的长期难题.. 由于这些原因,QSL在过去的45年里得到了广泛的研究,但到目前为止仍然存在 似乎不是理想的QSL材料。 在这篇演讲中,我将介绍我们对两种类型的QSL候选人的结果,几何上是失败的 化合物YbMgGaO4和YbZnGaO4具有三角形晶格,Kitaev材料α-RuCl3 蜂窝晶格。 对于YbMgGaO4和YbZnGaO4,我们发现它们是真实的地面 状态是自旋玻璃,无序主要负责自旋液状观察[1]。 对于alpha-RuCl3,我们证明在锯齿形阶状态[2]中存在一种主导的Kitaev相互作用, 磁场可以将系统从有序状态驱动到可能的QSL状态[3,4]。 最后,我还将简要讨论我们最近在三维反铁磁体Cu3TeO6[5]中发现的拓扑磁矩。 *********************************** 68. 拓扑不变量:分类与诊断. 在这篇演讲中,我将介绍这两篇理论论文和一篇数值论文 导致《拓扑电子材料目录》的建立。 在里面 理论工作,我和我的合作者利用对称理论 指标(或拓扑量子化学)和真实空间结构的指标 拓扑结晶态,并从对称性中找到了穷举映射 价带的特征值与其拓扑不变量。 在数值计算中, 这些映射应用于设计一种全自动、快速的诊断方法 拓扑材料。 然后使用该方法查找多达8000个拓扑 超过40000种材料中的材料,在流行材料中注册 数据库。 在此基础上建立了拓扑材料数据库。 ************************************** 69. 银河考古的新时代. 了解负责星系形成和演化的物理过程,如 银河系是天体物理学的一个基本问题。 然而,一个关键的挑战是 目前只能观察到恒星的性质和轨道:了解发生了什么 在早期的银河系中,人们必须探索“考古”技术。 银河系 由于正在进行的大规模调查(天体测量, 光度学,光谱学,星号学),提供了几个数量级以上的恒星 比以前多了。 在这篇演讲中,我将与这些调查讨论新的“现象学”机会。 i 将介绍一套新的机器学习工具,以最大限度地利用光谱信息 (LAMOST)、光度通量(Gaia)和光曲线(TESS)。 我也会介绍新的 深光学时代银河考古学的机遇,如LSST和DES。 *************************************** 70. 代数自旋液体中的单极:关于二维量子磁性的统一观点 量子磁体提供了强相互作用量子的最简单例子. 重要的是,他们继续抵制对一个空间之上的全面理解 维度。 在这篇演讲中,我将讨论一个单一的有效理论,量子 电动力学(QED3),描述不同二维上的多个阶数 统一框架中的格。 这个理论包括光子,狄拉克的四种口味 费米子,以及单极子,一个重要的激发类驱动 禁闭。 通过解决单极及其长期的未决问题 对称性质,我们自然解释了两个二分上的各种顺序 晶格,如方形和蜂窝,以及非双晶三角形和. 卡戈姆晶格。 我们的理论指出了这两种类型的两种不同的场景 格子。 特别是,在非双晶晶格的自旋模型中,QED3理论可能是 稳定,产生稳定的代数自旋液相。 *************************************** 71. 非热粒子加速磁连接法 磁重联是一种常用的多尺度等离子体过程,可以快速转换. 在块状等离子体流、热粒子和非热粒子中,磁能转化为动能 分布。 一个尚未解决的重要问题是非热加速 重连区的带电粒子。 特别是大规模理论和三维扩展. 这个问题鲜为人知。 为了解决这个问题,我们利用了许多 解决这个问题的工具。 利用LANL的VPIC代码,研究了磁性粒子的加速度 通过大规模的三维动力学模拟重新连接,以检查可能是的几种效应 重要的,包括预先存在的波动,扭结和二次撕裂不稳定性,和开放 边界条件。 结果表明,重连层中的粒子加速度是 令人惊讶的稳健,尽管发展的三维湍流和不稳定性。 此外,还有 在三维模拟中观察到的粒子加速度有时比三维模拟更有效 相应的二维情况,表明可行的新的加速机制。 然后,我们通过在背景中求解帕克的输运方程来研究大规模的重连加速 由MHD模拟提供的重新连接流。 由于压缩效应,模拟 建议快速粒子加速到重连层的高能量。 本研究澄清了 重新连接层中粒子加速度的性质,对于理解粒子可能是很重要的 太阳耀斑和其他天体物理环境中的加速度和等离子体能量。 ************************************* 72. 神经网络及其在物理科学中的应用 近年来,神经网络因其在各种领域的应用而备受关注 日常方面,包括面部/声音识别和数据挖掘。 尽管他们能力非凡, 神经网络被严重利用不足,在物理上没有充分发挥其潜力 科学。 在这篇演讲中,我将简要解释基本概念以及一些令人兴奋的前沿思想 在神经网络中。 我将讨论应用这个简单而有趣的想法的机会 物理科学以我对银河系的研究为例。 特别是,我将描述 如何将数据驱动模型和神经网络相结合才能成为有效的工具 来自低分辨率光谱的信息,并涉及物理科学的各个领域-例如 天文学中光谱学和星号学的研究。 ************************************* 73. 原行星盘中尘埃-气体相互作用的动力学及其对行星形成的影响 大多数年轻的低质量恒星被圆盘包围,由大型气藏组成 以及最终形成行星系统的尘埃。 近年来,空间分辨率高. 由ALMA对这些磁盘的观察揭示了许多提供有趣的细节 磁盘物理和尘埃动力学的约束,这两个都是必不可少的 理解行星的形成。 我们进行高分辨率,二维水动力. 全球磁盘的模拟,包括灰尘反馈的影响。 我们发现磁盘显示了丰富的内容 各种行为,取决于灰尘和气体的相互作用。 这些特征包括 准轴对称环和非对称粉尘陷阱都是不稳定的 可能的不稳定性。 我们还首次展示了流不稳定在全局中的影响 磁盘模拟。 这些效应为促进其形成提供了一种有前途的新途径 在这样的磁盘中有许多行星。 我们使用我们的模拟制作合成粉尘排放图像. 结果并讨论了模拟与观测的比较。 ************************************ 74. 超导体中的量子格里菲斯奇点和超量子拓扑材料中的对数周期量子振荡 量子相变是凝聚态物理中最重要的课题之一。 为第一个 时间上,我们观察了超导体-金属转移的动力临界指数的发散 在GaN衬底上生长的超薄Cyrtalline Ga薄膜中,这是量子的主要特征 在二维超导体[1,2]中,格里菲斯的奇异性表现出一种新的量子相变。 这个 在LAO/STO(110)界面超导体[3]和单层NbSe2中进一步揭示了这一发现 电影[4]。 众所周知,到目前为止有两类量子振荡。 一是B周期. 振荡,如介观系统的AB和AAS效应和小帕克斯振荡 超导系统。 另一个,即。 量子化Landau的1/B周期SD H振荡 水平,可能更普遍。 然而,我们发现了一种新的量子振荡 高质量拓扑材料中的量子极限,表现出奇异的对数B期。 进一步的理论 研究表明,Efimovian束缚态可以解释对数周期量子 振荡(即振荡)。 离散尺度不变性)好。 [5] ************************************ 75. 在三维+一维拓扑有序相和三重链接中的广义模块化变换 环编织不变 以前,拓扑有序相在2+1维已经得到了很好的研究,部分是由于 它与1+1D共形场理论(CFT)密切相关。 尤其是模块化转换, 最初是在CFT的背景下开发的,已经被证明包含了关于CFT的信息 点状粒子的编织统计,并表征拓扑有序的特征 阶段在2+1D。 在这篇文章中,我讨论了这些在3+1D中的自然推广 有序相位,其中广义模块化变换被发现是直接相关的 延伸环状激发的编织。 **************************************** 76. 狄拉克材料:理论与材料建模. 狄拉克材料是狄拉克费米子的港湾,其低能激发受狄拉克方程的控制 相对论量子力学。 相当多的材料最近感兴趣的浓缩物质 群落可分为Dirac材料,如石墨烯、拓扑绝缘体和山谷电子学 材料。 在这篇演讲中,我将从BerryyPphase的观点介绍“Diracologygy”,包括G相关 理论和计算方面。 在此之后,我的小组将在这方面取得最近的进展 研究,包括 (1)实现山谷电子学的材料预测; (2)Z2=0系统的拓扑方面; (3)时间pp g略写:来自“琐碎”氧化物的Chern绝缘体。 ********************************** 77. 量子多体系统中的平衡、热化和纠缠 物理学在我们的经验中最熟悉的事实是,物理系统自发地倾向于到达 平衡,并加热。 这一非常有害的事实一直与根本规律不一致 物理,那是时间逆转。 特别地,孤立的量子动力学是酉的、可逆的和NO的 熵可以增加。 长期以来,人们一直认为,即使可以观察到的数量也可以加热 全球系统处于远离平衡的纯状态。 发生这种情况的机制之一是 本征状态热化假说(ETH),它指出热化发生在单一的水平上 本征态。 最近,人们已经明白,纠缠是这种现象的根源,而这些 现象在实验上与超冷原子气体的设置有关。 而且,还有一个. 对那些拒绝加热的系统的强烈兴趣。 在FACT中,有趣的Thinggs已经pppp远离 平衡。 毕竟,没有人可以提取方式工作(没有其他变化)-给出一个例子从一个平衡状态。 这种拒绝热化的状态要么是微调的,要么是那些被称为许多身体局部状态的状态。 在这篇演讲中,我将介绍所有这些概念的当前回顾,并提出一些 新问题和初步解决方向。 特别是,即使我们知道纠缠是 涉及热化和ETH,ITS的作用并不清楚,即因为纠缠是 非常强大,即使在不加热的系统中。 我将展示一些新的研究结果 纠缠谱,表明纠缠水平统计可能包含相关信息 如何遵守ETH。 ************************************* 78. 通过标题映射自旋凝聚体的相图:通过映射自旋凝聚体的相图 绝热量子相变 我们实验研究了钠自旋凝结物中的两个量子相变 浸入微波敷料场。 与磁场相反,微波 敷料场可以诱导二次塞曼的负值和正值 能源。 我们证明了在相图中许多以前未被探索的区域 自旋凝聚可以通过绝热调谐微波场来研究 跨越两个量子相变中的一个。 这种方法克服了两个主要问题 与一些广泛使用的方法相关的实验挑战,并且是适用的 其他原子物种。 我们的数据和平均场理论之间的协议 还讨论了自旋玻色气体。 ***************************************** 79. 非交换几何的第一眼 我们将跟随阿兰·康尼斯(AlainConnes)在法国学院(1985年)的首次讲座 展示(在某种意义上)数学框架是如何从对数学框架的理解中产生的 量子物理导致了非交换空间的概念。 我们也会谈谈 如果我们没有时间的话,一些进一步的发展。 ******************************************* 80. 经典和量子磁体中物质的拓扑态,经典和量子磁体中物质的拓扑态 拓扑相已经被探索在物理学的各个领域,如半导体 物理学,相关电子系统,液氦-3,冷原子系统和光子学。 这导致了最近出现的材料的基础,如拓扑带绝缘体, 颠覆g逻辑超导体/上流体和颠覆g逻辑光子晶体。 在这次谈话中,我会说话 关于磁体中物质的两种拓扑状态,一种是经典的拓扑自旋波 磁体和另一个是量子磁体中的多极态。 在第一部分,我提议 整数量子霍尔态的静磁自旋波模拟,其中自旋波 长波长度(千分尺尺度)的传播是由磁偶极子驱动的. 互动。 与相对论性sppin-轨道相互作用一样,二极体相互作用ppy也起着重要的作用 自旋轨道锁定,使二维铁磁薄膜具有周期性结构. 可以用非零Chern整数承载自旋波带,从而产生拓扑边缘 自旋波传播的模式。 在第二部分的讨论中,我将争论某一个 量子磁体中的多极态可以描述为Z2拓扑级相, 主持一个类似的低能有效GGGauge理论,如Z2量子sppinLiqquid。 一个变量 由量子自旋模型中提出的``Z2多极态‘导出的ansatz可以 解释在前面的精确对角化研究中发现的几个不寻常的特征 相同的量子自旋模型。 ************************************* 81. 安德森定位的简单物理:安德森定位的简单物理: 概况和应用 本文简要介绍了强安德森国产化的物理原理 波浪。 我们将介绍理论和结果的主要方法和结果 一维无序系统中波传播的实验研究。 重点将放在描述、检测和潜在应用上 无序引起的共振。 *********************************** 82. 检测完全间隙和节点标题中的Majorana费米子:检测完全间隙和节点中的Majorana费米子 拓扑超导体 最近,Andreev的零偏置电导峰(ZBCPs)取得了重要进展 反射型实验,这可能是由于Majorana费米子,已经观察到 超导体/半导体异质结构。 然而,最近的实验不能排除其他的 增强局部Andreev反射的可能起源。 在这篇文章中,我们证明了两个空间分离但强烈耦合的Majorana费米子可以很强 增强两个空间分离引线之间的交叉Andreev反射振幅,即 分别连接到两个Majorana费米子。 由此产生的强电流相关性 镜头噪声可用于检测Majorana费米子的非局部性质。 在所谓的DIIID III类拓扑拓扑中,MajoranaMajorana费米子费米子的创建、创建和检测 还将讨论保持时间反转对称性的超导体。 在这篇文章中,我们还讨论了在节点超导体中检测Majorana费米子的可能性。 我们预测Majorana费米子平坦带出现在d_{x^2-y^2}波超导体中 拉什巴自旋轨道耦合。 不像出现在上的零能量费米子安德列夫束缚态 通常的dd波超导体、超导体的[[110110]]边,在同一边缘上的MajoranaMajorana费米子费米子是不可能的 由平面内磁场提升到有限能量。 因此,d_{x^2的隧道光谱 ^2}波超导体在平面内磁场作用下,产生了三重峰特征 由Majorana费米子引起的中央ZBCP。 *********************************************** 83. 银河考古的新时代. 银河系是天体物理学的一个基本问题。 然而,一个关键的挑战是 目前只能观察到恒星的性质和轨道:了解发生了什么 在早期的银河系中,人们必须探索“考古”技术。 银河系 由于正在进行的大规模调查(天体测量, 光度学,光谱学,星号学),提供了几个数量级以上的恒星 比以前多了。 在这篇演讲中,我将与这些调查讨论新的“现象学”机会。 i 将介绍一套新的机器学习工具,以最大限度地利用光谱信息 (LAMOST)、光度通量(Gaia)和光曲线(TESS)。 我也会介绍新的 深光学时代银河考古学的机遇,如LSST和DES。 ********************************************* 84. 代数自旋液体中的单极: 对二维量子磁性的统一看法 量子磁体提供了强相互作用量子的最简单例子. 重要的是,他们继续抵制对一个空间之上的全面理解 维度。 在这篇演讲中,我将讨论一个单一的有效理论,量子 电动力学(QED3),描述不同二维上的多个阶数 统一框架中的格。 这个理论包括光子,狄拉克的四种口味 费米子,以及单极子,一个重要的激发类驱动 禁闭。 通过解决单极及其长期的未决问题 对称性质,我们自然解释了两个二分上的各种顺序 晶格,如方形和蜂窝,以及非双晶三角形和. 卡戈姆晶格。 我们的理论指出了这两种类型的两种不同的场景 格子。 特别是,在非双晶晶格的自旋模型中,QED3理论可能是 稳定,产生稳定的代数自旋液相。 ************************** 85. 非热粒子加速磁连接法 磁重联是一种常用的多尺度等离子体过程,可以快速转换. 在块状等离子体流、热粒子和非热粒子中,磁能转化为动能 分布。 一个尚未解决的重要问题是非热加速 重连区的带电粒子。 特别是大规模理论和三维扩展. 这个问题鲜为人知。 为了解决这个问题,我们利用了许多 解决这个问题的工具。 利用LANL的VPIC代码,研究了磁性粒子的加速度 通过大规模的三维动力学模拟重新连接,以检查可能是的几种效应 重要的,包括预先存在的波动,扭结和二次撕裂不稳定性,和开放 边界条件。 结果表明,重连层中的粒子加速度是 令人惊讶的稳健,尽管发展的三维湍流和不稳定性。 此外,还有 在三维模拟中观察到的粒子加速度有时比三维模拟更有效 相应的二维情况,表明可行的新的加速机制。 然后我们研究大范围 通过在背景中求解帕克的输运方程来重新连接加速度 由MHD模拟提供的重新连接流。 由于压缩效应,模拟 建议快速粒子加速到重连层的高能量。 本研究澄清了 重新连接层中粒子加速度的性质,对于理解粒子可能是很重要的 太阳耀斑和其他天体物理环境中的加速度和等离子体能量。 ************************************ 86. 神经网络及其在物理科学中的应用 近年来,神经网络因其在各种领域的应用而备受关注 日常方面,包括面部/声音识别和数据挖掘。 尽管他们能力非凡, 神经网络被严重利用不足,在物理上没有充分发挥其潜力 科学。 在这篇演讲中,我将简要解释基本概念以及一些令人兴奋的前沿思想 在神经网络中。 我将讨论应用这个简单而有趣的想法的机会 物理科学以我对银河系的研究为例。 特别是,我将描述 如何将数据驱动模型和神经网络相结合才能成为有效的工具 来自低分辨率光谱的信息,并涉及物理科学的各个领域-例如天文学中光谱学和星号学的研究。 **************************** 87. 一维过剩是一种动态现象 过流密度通常与螺旋度模量有关,这是螺旋度模量的静态响应 自由能相扭转。 在一个维度中,螺旋度模量通常消失 在有限温度下的热力学极限中,意味着没有超流体。 然而,最近,实验观察了液体中超流动性的4He浓度[1]报道了一维纳米孔.. 这促使我们重新考虑这一概念超流性及其与完全静态的螺旋度模量的关系 数量。 我们发展了一维超流理论,作为一个本质上的动力学 现象[2]。 我们的结果与液体的实验结果定性一致 4他在一维纳米孔,并预测一个微弱但显著的频率 超流反应开始的依赖性。 ***************************(总数: 87) 2020-07-22 |
|
相关推荐 |
|
只有小组成员才能发言,加入小组>>
小黑屋| 手机版| Archiver| 电子发烧友 ( 湘ICP备2023018690号 )
GMT+8, 2024-11-26 03:26 , Processed in 0.906766 second(s), Total 66, Slave 49 queries .
Powered by 电子发烧友网
© 2015 bbs.elecfans.com
关注我们的微信
下载发烧友APP
电子发烧友观察
版权所有 © 湖南华秋数字科技有限公司
电子发烧友 (电路图) 湘公网安备 43011202000918 号 电信与信息服务业务经营许可证:合字B2-20210191 工商网监 湘ICP备2023018690号