A5017697787- Physics of Superconductivity and Magnetism
- Quantum many-body systems
- Advanced Condensed Matter Physics
- Topological Materials and Phenomena
- Quantum and electron transport phenomena
- Cold Atom Physics and Bose-Einstein Condensates
- Magnetic and transport properties of perovskites and related materials
- Theoretical and Computational Physics
- Quantum, superfluid, helium dynamics
- Semiconductor Quantum Structures and Devices
- Magnetic properties of thin films
- Graphene research and applications
- Organic and Molecular Conductors Research
- Atomic and Subatomic Physics Research
- MXene and MAX Phase Materials
- Random lasers and scattering media
- Astro and Planetary Science
- Neural Networks and Applications
- Advanced Chemical Physics Studies
- Topological and Geometric Data Analysis
- Iron-based superconductors research
- Quantum optics and atomic interactions
- 2D Materials and Applications
- Nonlinear Photonic Systems
- Noncommutative and Quantum Gravity Theories
University of Science and Technology of China
2023-2025
Peng Huanwu Center for Fundamental Theory
2025
Hefei University
2025
Institute of Theoretical Physics
2022-2024
Northwest University
2022-2024
Institute of Modern Physics
2009-2024
Flatiron Health (United States)
2019-2023
William & Mary
2019-2021
Williams (United States)
2019-2021
Renmin University of China
2016-2019
The Hubbard model represents the fundamental for interacting quantum systems and electronic correlations. Using two-dimensional half-filled at weak coupling as a testing ground, we perform comparative study of comprehensive set state-of-the-art many-body methods. Upon cooling into its insulating antiferromagnetic ground state, hosts rich sequence distinct physical regimes with crossovers between high-temperature incoherent regime, an intermediate-temperature metallic low-temperature regime...
The Hubbard model at temperatures above the Néel transition, despite being a paramagnet, can exhibit rich physics due to interplay of Fermi surface, on-site interaction U and thermal fluctuations. Nevertheless, understanding crossover remains only qualitative level, because intrinsically smooth behavior. Employing an improved variant numerically exact auxiliary-field quantum Monte Carlo algorithm equipped with numerical analytic continuation, we obtain broad variety thermodynamic dynamical...
State-of-the-art numerical techniques suggest that charge order in the 2D Hubbard model sets at a nonzero temperature, answering major open question physics of this paradigmatic quantum materials.
Accurate simulations of the two-dimensional (2D) Hubbard model constitute one most challenging problems in condensed matter and quantum physics. Here we develop a tangent space tensor renormalization group (tanTRG) approach for calculations 2D at finite temperature. An optimal evolution density operator is achieved tanTRG with mild O(D3) complexity, where bond dimension D controls accuracy. With boost low-temperature large-scale systems on up to width-8 cylinder 10×10 square lattice. For...
Proving an equivalence between two theories---one that describes a transition kinds of insulating states and another models changes spin states---would offer step toward unified theoretical understanding different condensed-matter systems. New computer simulations provide evidence for this duality by showing the critical points these theories have identical properties.
Using a leading algorithmic implementation of the functional renormalization group (fRG) for interacting fermions on two-dimensional lattices, we provide detailed analysis its quantitative reliability Hubbard model. In particular, show that recently introduced multiloop extension fRG flow equations self-energy and two-particle vertex allows precise match with parquet approximation also lattice problems. The refinement respect to previous fRG-based computation schemes relies an accurate...
The interplay between thermal and quantum fluctuations controls the competition phases of matter in strongly correlated electron systems. We study finite-temperature properties coupled two-dimensional doped Hubbard model using minimally-entangled typical states (METTS) method on width $4$ cylinders. discover that a phase characterized by commensurate short-range antiferromagnetic correlations no charge ordering occurs at temperatures above half-filled stripe extending to zero temperature....
It is expected that the interplay between nontrivial band topology and strong electron correlation will lead to very rich physics. Thus a controlled study of competition great interest. Here, employing large-scale quantum Monte Carlo simulations, we provide concrete example Kane-Mele-Hubbard model on an AA-stacking bilayer honeycomb lattice with interlayer antiferromagnetic interaction. Our simulation identified several different phases: spin Hall insulator (QSH), $xy\text{-plane}$ Mott...
$A\phantom{\rule{0}{0ex}}b$ $i\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}o$ computations of finite-temperature properties are important in fermion systems such as correlated models, ultracold Fermi atomic gases, and optical lattices, realistic materials. Here, the authors present a highly accurate approach that eliminates sign problem standard determinantal quantum Monte Carlo (DQMC) using gauge constraint...
We propose a general scheme for diagnosing interaction-driven topological phases in the weak interaction regime using exact diagonalization (ED). The comprises analysis of eigenvalues point-group operators many-body eigenstates and correlation functions physical observables to extract symmetries order parameters numbers underlying ground states at thermodynamic limit from relatively small size system afforded by ED. As concrete example, we investigate effects on half-filled spinless fermions...
In this work, we study the correlation between entanglement and negative sign problem in quantum Monte Carlo for simulation of low-dimensional strongly correlated many body systems. Entanglement entropy characterizes difficulty many-body with tensor network state related methods, while average measures a variety methods. Although there exist cases where one type method works better than other, it is desirable to find possible general hard systems regarding computational complexity. We take...
We report discovery of a topological Mott insulator in strongly-correlated Dirac semimetals. Such an interaction-driven state has been theoretically proposed but not yet observed with unbiased large scale numerical simulations. In our model, interactions between electrons are mediated by Ising spins transverse field. The results indicate that the mass term is dynamically generated and resulting quantum phase transition belongs to (2+1)D $N=8$ chiral universality class. These conclusions stem...
We study a lattice model of interacting Dirac fermions in $(2+1)$ dimensions space-time with an SU(4) symmetry. While increasing the interaction strength, this undergoes continuous quantum phase transition from weakly semimetal to fully gapped and nondegenerate without condensing any fermion bilinear mass operator. This unusual mechanism for generation is consistent recent studies topological insulators/superconductors, also progress QCD community.
Topological phase transitions in free fermion systems can be characterized by closing of single-particle gap and change topological invariants. However, the presence electronic interactions, are more complicated. In paper I this series (arXiv:1510.07816), we have developed an efficient scheme to evaluate invariants based on Green's function formalism. Here, II, demonstrate four interaction-drive (TPTs) two-dimensional (2D) interacting insulators (TIs) via large-scale quantum Monte Carlo...
With Monte Carlo methods, we investigate the relaxation dynamics of a domain wall in two-dimensional random-field Ising model with driving field. The short-time dynamic behavior at depinning transition is carefully examined, and roughening process observed. Based on scaling form, accurately determine field, static exponents, local global roughness exponents. In contrast to usual assumption, results indicate that interface does not belong universality class Edwards-Wilkinson equation....
We perform large-scale, numerically exact calculations on the two-dimensional interacting Fermi gas with a contact attraction. Reaching much larger lattice sizes and lower temperatures than previously possible, we determine systematically finite-temperature phase diagram of Berezinskii-Kosterlitz-Thouless (BKT) transitions for interaction strengths ranging from BCS to crossover BEC regimes. The evolutions pairing wave functions fermion Cooper pair momentum distributions temperature are...
The admixture of spin-singlet and spin-triplet pairing states in superconductors can be typically induced by breaking spatial inversion symmetry. Employing the numerically exact auxiliary-field quantum Monte Carlo method, we study such mixed-parity phenomena attractive fermions with Rashba spin-orbit coupling (SOC) a two-dimensional optical lattice at finite temperature. We systematically explore evolution essential structure both singlet triplet channels versus temperature, fermion filling,...
Finite-temperature grand-canonical computations based on field theory are widely applied in areas including condensed matter physics, ultracold atomic gas systems, and the lattice gauge theory. However, these calculations have computational costs scaling as ${N}_{s}^{3}$ with size of or basis set, ${N}_{s}$. We report a new approach systematically controllable low-rank factorization that reduces such to ${N}_{s}{N}_{e}^{2}$, where ${N}_{e}$ is average number fermions system. In any realistic...
The aim of this series two papers is to discuss topological invariants for interacting insulators (TIs). In the first paper (I), we provide a paradigm efficient numerical evaluation scheme invariants, in which demystify procedures and techniques employed calculating ${Z}_{2}$ invariant spin Chern number via zero-frequency single-particle Green's function quantum Monte Carlo (QMC) simulations. Here introduce an interpolation process overcome ubiquitous finite-size effect, so that calculated...
Symmetry protected topological (SPT) phases in free fermion and interacting bosonic systems have been classified, but the physical phenomena of fermionic SPT not fully explored. Here, employing large-scale quantum Monte Carlo simulation, we investigate edge physics a bilayer Kane-Mele-Hubbard model with zigzag ribbon geometry. Our unbiased numerical results show that modes are gapped out by interaction, while remain gapless at $(1+1)d$ boundary, before bulk phase transition to topologically...
Manipulating magnetism of low-dimensional materials is great importance for their practical applications. Here, using first-principles calculations, we report a systematic investigation the magnetic properties C-doped H saturated zigzag phosphorene nanoribbons (H-ZPNRs), which are rather different from those 2D periodic systems due to quantum size effect. First all, observed greatly enhanced moment locating mainly on C atom and also slightly its surrounding P atoms. Our results indicated...
Fermi-Hubbard model is a fundamental lattice for describing correlated electron systems in condensed matter physics, with profound connection to high-temperature superconductivity. In recent years, quantum simulation cold atoms has emerged as an important paradigm studying the model, while advancements many-body computations have contributed our understanding of its properties. Notably, ultracold-atom experiment achieved celebrated antiferromagnetic (AFM) phase transition three-dimensional...
The domain wall dynamics in magnetic nanowires is numerically studied with the Landau-Lifshitz-Gilbert equation. Below Walker breakdown threshold, presents a stable propagation, while above threshold where retrograde mode dominates, oscillation period controlled by external field and anisotropy. More importantly, dynamic effects of quenched disorder on motion are explored. A continuous pinning-depinning phase transition detected. scaling form analyzed data collapse velocity, both static...