A5045176105- Quantum many-body systems
- Topological Materials and Phenomena
- Quantum and electron transport phenomena
- Quantum Computing Algorithms and Architecture
- Physics of Superconductivity and Magnetism
- Quantum Information and Cryptography
- Advanced Condensed Matter Physics
- Cold Atom Physics and Bose-Einstein Condensates
- Theoretical and Computational Physics
- Graphene research and applications
- Advanced Thermodynamics and Statistical Mechanics
- Opinion Dynamics and Social Influence
- Neural Networks and Reservoir Computing
- Spectroscopy and Quantum Chemical Studies
- Quantum chaos and dynamical systems
- Quantum, superfluid, helium dynamics
- Social Media and Politics
- Electronic and Structural Properties of Oxides
- Canadian Policy and Governance
- Model Reduction and Neural Networks
- 2D Materials and Applications
- Magnetic and transport properties of perovskites and related materials
- Rare-earth and actinide compounds
- Iron-based superconductors research
- Social Sciences and Governance
University of British Columbia
2022-2024
Colorado State University
2024
The University of Texas at Austin
2016-2023
McGill University
2019-2022
Duke University
2022
Dartmouth College
2022
George Mason University
2022
Stanford University
2022
Tilburg University
2022
McMaster University
2022
Despite being forbidden in equilibrium, spontaneous breaking of time translation symmetry can occur periodically driven, Floquet systems with discrete time-translation symmetry. The period the resulting crystal is quantized to an integer multiple drive period, arising from a combination collective synchronization and many body localization. Here, we consider simple model for one dimensional which explicitly reveals rigidity emergent oscillations as varied. We numerically map out its phase...
One of the simplest proposed experimental probes a Majorana bound-state is quantized (2e^2/h) value zero-bias tunneling conductance. When temperature somewhat larger than intrinsic width peak, conductance no longer quantized, but peak can remain. Such non-quantized has been recently reported for semiconducting nanowires with proximity induced superconductivity. In this paper we analyze relation to presence end-states, by simulating multi-band wires realistic amounts disorder. We show that...
The ends of one-dimensional p+ip superconductors have long been predicted to possess localized Majorana fermion modes. We show that end states survive beyond the strict 1D single-channel limit so as sample width does not exceed superconducting coherence length, and exist when an odd number transverse quantization channels are occupied. Consequently we find system undergoes a sequence topological phase transitions driven by changing chemical potential. These observations make it feasible...
A fundamental open problem in condensed matter physics is how the dichotomy between conventional and topological band insulators modified presence of strong electron interactions. We show that there are 6 new electronic have no non-interacting counterpart. Combined with previously known band-insulators, these produce a total 8 topologically distinct phases. Two simple physical description as Mott which spins form spin analogs familiar band-insulator. The remaining obtained combinations two...
We introduce a model to explain the observed ferromagnetism and superconductivity in LAO/STO oxide interface structures. Because of polar catastrophe mechanism, 1/2 charge per unit cell is transferred layer. argue that this localizes orders ferromagnetically via exchange with conduction electrons. Ordinarily, would destroy superconductivity, but, due strong spin-orbit coupling near interface, magnetism can coexist by forming Fulde-Ferrell-Larkin-Ovchinikov-type condensate Cooper pairs at...
We introduce a novel class of phase transitions separating quantum states with different entanglement features. An example such an "entanglement transition" is provided by the many-body localization transition in disordered systems, as it separates highly entangled thermal at weak disorder from localized low strong disorder. In spirit random matrix theory, we describe simple model for where physical system lives "holographic" boundary bulk tensor network. Using replica trick approach, map...
We study the dynamical melting of "hot" one-dimensional many-body localized systems. As disorder is weakened below a critical value these non-thermal quantum glasses melt via continuous phase transition into classical thermal liquids. By accounting for collective resonant tunneling processes, we derive and numerically solve an effective model such quantum-to-classical transitions compute their universal properties. Notably, liquid exhibits broad regime anomalously slow sub-diffusive...
Monitored quantum circuits can exhibit an entanglement transition as a function of the rate measurements, stemming from competition between scrambling unitary dynamics and disentangling projective measurements. We study how in nonunitary be enriched presence charge conservation, using combination exact numerics mapping onto statistical mechanics model constrained hard-core random walkers. uncover charge-sharpening that separates different phases with volume-law scaling entanglement,...
We characterize the variational power of quantum circuit tensor networks in representation physical many-body ground states. Such are formed by replacing dense block unitaries and isometries standard local circuits. explore both matrix product states multiscale entanglement renormalization Ansatz, introduce an adaptive method to optimize resulting circuits high fidelity with more than 104 parameters. benchmark their expressiveness against networks, as well other common architectures, for 1D...
We compare topological insulator materials and Rashba-coupled surfaces as candidates for engineering $p+\mathit{ip}$ superconductivity. Specifically, in each type of material we examine (1) the limitations to inducing superconductivity by proximity an ordinary $s$-wave superconductor, (2) robustness resulting against disorder. find that insulators have strong advantages both regards: There are no fundamental barriers superconductivity, induced is immune In contrast, quantum wires or surface...
It is well known that the three-dimensional (3D) electronic topological insulator (TI) with charge-conservation and time-reversal symmetry cannot have a trivial insulating surface preserves symmetry. often implicitly assumed if TI both symmetries then it must be gapless. Here we show possible for to gapped preserving, at expense of having surface-topological order. In contrast analogous bosonic insulators, this symmetric order intrinsically non-Abelian. We provides complete nonperturbative...
We construct and classify chiral topological phases in driven (Floquet) systems of strongly interacting bosons, with finite-dimensional site Hilbert spaces, two spatial dimensions. The construction proceeds by introducing exactly soluble models edges, which the presence many-body localization (MBL) bulk are argued to lead stable phases. These do not require any symmetry fact owe their existence absence energy conservation systems. Surprisingly, we show that they classified a quantized index,...
A recent work [1] demonstrated, for an ideal spinless p+ip superconductor, that Majorana end-states can be realized outside the strict one-dimensional limit, so long as: 1) sample width does not greatly exceed superconducting coherence length and 2) odd number of transverse sub-bands are occupied. Here we extend this analysis to case effective superconductor engineered from Rashba spin-orbit coupled surface with induced magnetization superconductivity, find a new features. Specifically,...
We propose and analyze two distinct routes toward realizing interacting symmetry-protected topological (SPT) phases via periodic driving. First, we demonstrate that a driven transverse-field Ising model can be used to engineer complex interactions which enable the emulation of an equilibrium SPT phase. This phase remains stable only within parametric time scale controlled by driving frequency, beyond its features break down. To overcome this issue, consider alternate route based upon...
We derive general constraints on the existence of many-body localized (MBL) phases in presence global symmetries, and show that MBL is not possible with symmetry groups protect multiplets (e.g. all non-Abelian groups). Based simple representation theoretic considerations, we Mermin-Wagner-type principles governing alternative fates non-equilibrium dynamics isolated, strongly disordered quantum systems. Our results rule out protected topological groups, as well time-reversal electronic...
We study the infinite-temperature properties of an infinite sequence random quantum spin chains using a real-space renormalization group approach, and demonstrate that they exhibit nonergodic behavior at strong disorder. The analysis is conveniently implemented in terms SU(2)_{k} anyon include Ising Potts as notable examples. Highly excited eigenstates these systems usually associated with critical ground states, leading us to dub them "quantum glasses." argue random-bond Heisenberg...