A5008810579- Physics of Superconductivity and Magnetism
- Topological Materials and Phenomena
- Advanced Condensed Matter Physics
- Quantum many-body systems
- Graphene research and applications
- Quantum and electron transport phenomena
- Cold Atom Physics and Bose-Einstein Condensates
- Iron-based superconductors research
- 2D Materials and Applications
- Theoretical and Computational Physics
- Quantum Computing Algorithms and Architecture
- Quantum Information and Cryptography
- Rare-earth and actinide compounds
- Magnetic and transport properties of perovskites and related materials
- Electronic and Structural Properties of Oxides
- Surface and Thin Film Phenomena
- Algebraic structures and combinatorial models
- Quantum, superfluid, helium dynamics
- Organic and Molecular Conductors Research
- Black Holes and Theoretical Physics
- Inorganic Fluorides and Related Compounds
- Quantum chaos and dynamical systems
- Atomic and Subatomic Physics Research
- Quantum Chromodynamics and Particle Interactions
- Opinion Dynamics and Social Influence
Tsinghua University
2016-2025
Guangxi Normal University
2017-2025
Anhui Normal University
2014-2024
Beihang University
2023-2024
Stanford University
2008-2023
State Key Laboratory of Low-Dimensional Quantum Physics
2023
Beijing Academy of Quantum Information Sciences
2019-2020
Collaborative Innovation Center of Quantum Matter
2014-2019
Air Force Engineering University
2011-2016
Nanchang University
2015
We study a spin $S$ quantum Heisenberg model on the Fe lattice of rare-earth oxypnictide superconductors. Using both large and $N$ methods, we show that this exhibits sequence two phase transitions: from high-temperature symmetric to narrow region intermediate ``nematic'' phase, then low-temperature ordered phase. Identifying phases by their broken symmetries, these correspond precisely structural (tetragonal monoclinic) magnetic transitions have been recently revealed in neutron-scattering...
Intrinsic magnetic topological insulator (TI) is a stoichiometric compound possessing both inherent order and electronic states. Such material can provide shortcut to various novel quantum effects but remains elusive experimentally so far. Here, we report the experimental realization of high-quality thin films an intrinsic TI---MnBi$_2$Te$_4$---by alternate growth Bi$_2$Te$_3$ quintuple-layer MnTe bilayer with molecular beam epitaxy. The shows archetypical Dirac surface states in...
We investigate the stability of a quadratic band-crossing point (QBCP) in 2D fermionic systems. At noninteracting level, we show that QBCP exists and is topologically stable for Berry flux +/-2pi if symmetry group has either fourfold or sixfold rotational symmetries. This putative free-fermion marginally unstable to arbitrarily weak short-range repulsive interactions. consider both spinless spin-1/2 fermions. Four possible ordered states result: quantum anomalous Hall phase, spin nematic...
Topological semimetals have recently attracted extensive research interests as host materials to condensed matter physics counterparts of Dirac and Weyl fermions originally proposed in high energy physics. These with linear dispersions near the or points obey Lorentz invariance, chiral anomaly leads novel quantum phenomena such negative magnetoresistance. The invariance is, however, not necessarily respected physics, thus Lorentz-violating type-II strongly tilted cones can be realized...
We perform highly accurate density matrix renormalization group (DMRG) simulations to investigate the ground state properties of spin-1/2 antiferromagnetic square lattice Heisenberg $J_1$-$J_2$ model. Based on studies numerous long cylinders with circumferences up 14 spacings, we obtain strong evidence for a topological quantum spin liquid in region $0.41\leq J_2/J_1\leq 0.62$, separating conventional N\'eel and striped states smaller larger $J_2/J_1$, respectively. The is characterized...
We discuss a topological classification of insulators and superconductors in the presence both (non-spatial) discrete symmetries Altland-Zirnbauer spatial reflection symmetry any dimensions. By using structure bulk Dirac Hamiltonians minimal matrix dimensions explicit constructions invariants, we provide complete classification, which still has same dimensional periodicities with original classification. The reflection-symmetry-protected depends crucially on way operation is realized. When...
We establish the existence of a chiral spin liquid (CSL) as exact ground state Kitaev model on decorated honeycomb lattice, which is obtained by replacing each site in familiar lattice with triangle. This CSL spontaneously breaks time reversal symmetry but preserves other symmetries. There are two topologically distinct CSL's separated quantum critical point. Interestingly, vortex excitations nontrivial (Chern number +/-1) obey non-Abelian statistics.
In this supporting material for the main paper (the preceding submission), we show, in addition to related information experiments, additional discussion that cannot fit (due space constraint). It includes further about our experimental observations, wider implications of findings with various reported candidates pseudogap order, and a simple mean-field argument favors interpretations based on finite-Q order (density wave) seen by ARPES (whether "the order" is single or contains multiple...
Ideal Weyl semimetals with all nodes exactly at the Fermi level and no coexisting trivial surfaces in bulk, similar to graphene, could feature deep physics such as exotic transport phenomena induced by chiral anomaly. Here, we show that HgTe half-Heusler compounds, under a broad range of in-plane compressive strain, be materials nature realizing ideal four pairs topological surface arcs. Generically, find HgTe-class nontrivial band inversion noncentrosymmetry provide promising arena realize...
Abstract Quantum architecture search (QAS) is the process of automating engineering quantum circuits. It has been desired to construct a powerful and general QAS platform which can significantly accelerate current efforts identify advantages error-prone depth-limited circuits in NISQ era. Hereby, we propose framework differentiable (DQAS), enables automated designs an end-to-end fashion. We present several examples circuit design problems demonstrate power DQAS. For instance, unitary...
TensorCircuit is an open source quantum circuit simulator based on tensor network contraction, designed for speed, flexibility and code efficiency. Written purely in Python, built top of industry-standard machine learning frameworks, supports automatic differentiation, just-in-time compilation, vectorized parallelism hardware acceleration. These features allow to simulate larger more complex circuits than existing simulators, are especially suited variational algorithms parameterized...
In this letter, we obtain an exact formula for the entanglement entropy of ground state and all excited states Kitaev model. Remarkably, can be expressed in a simple separable form S = SG+SF, with SF free Majorana fermion system SG that Z2 gauge field. The field part contributes to universal "topological entropy" while is responsible nonlocal carried by vortices (visons) non-Abelian phase. Our result also enables calculation entire spectrum more general Renyi Based on our results propose new...
In this paper, we discover a new quantum Monte Carlo (QMC) method to solve the fermion sign problem in interacting models by employing Majorana representation of complex fermions. We call it "Majorana QMC" (MQMC). Especially, MQMC is free simulating class spinless on bipartite lattices at half filling and with arbitrary range (unfrustrated) interactions. To best our knowledge, first auxiliary field QMC (more generally, odd number species) models. simulations can be performed efficiently both...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCharge-transfer rates in symmetric and symmetry-disturbed derivatives of 9,9'-bianthrylN. Mataga, H. Yao, T. Okada, W. RettigCite this: J. Phys. Chem. 1989, 93, 9, 3383–3386Publication Date (Print):May 1, 1989Publication History Published online1 May 2002Published inissue 1 1989https://pubs.acs.org/doi/10.1021/j100346a004https://doi.org/10.1021/j100346a004research-articleACS PublicationsRequest reuse permissionsArticle...
We introduce a new class of superconductors (SCs) in two spatial dimensions with time reversal symmetry and reflection (i.e., mirror) symmetry. In the absence interactions, topological classes these SCs are distinguished by an integer-valued ($\mathbb{Z}$) invariant. When interactions included, we show that classification is modified to $\mathbb{Z}_8$. This clearly demonstrates can have qualitative effect on classifications gapped states matter more than one dimension.
Recent theoretical works have demonstrated various robust Abelian and non-Abelian fractional topological phases in lattice models with flat bands carrying Chern number $C=1$. Here we study hard-core bosons interacting fermions a three-band triangular-lattice model the lowest band of $C=2$. We find convincing numerical evidence bosonic quantum Hall effect at $\ensuremath{\nu}=1/3$ filling characterized by threefold quasidegeneracy ground states on torus, for each state, spectrum gap, gap...
After decades of explorations, suffering from low critical temperature and subtle nature, whether a metallic ground state exists in two-dimensional system beyond Anderson localization is still mystery. Supremely, phase coherence could be the key that unlocks its intriguing nature. This work reveals how quantum evolves across bosonic superconductor-metal-insulator transitions via magneto-conductance oscillations high-Tc superconducting films. A robust intervening anomalous characterized by...
Supersymmetry (SUSY) interchanges bosons and fermions but no direct evidences of it have been revealed in nature yet. In this letter, we observe that fluctuating pair density waves (PDW) consist two complex order parameters which can be superpartners the unavoidably-doubled Weyl three-dimensional lattice models. We construct explicit fermionic models featuring 3D show PDW is leading instability via a continuous phase transition as short-range interactions exceed critical value. Using...
Weyl semimetals are new states of matter which feature novel Fermi arcs and exotic transport phenomena. Based on first-principles calculations, we report that the chalcopyrites ${\mathrm{CuTlSe}}_{2}$, ${\mathrm{AgTlTe}}_{2}$, ${\mathrm{AuTlTe}}_{2}$, ${\mathrm{ZnPbAs}}_{2}$ ideal semimetals, having largely separated points ($\ensuremath{\sim}0.05\text{ }\text{ }{\AA{}}^{\ensuremath{-}1}$) uncovered amenable to experimental detections. We also construct a minimal effective model capture...
Many aspects of many-body localization (MBL) transitions remain elusive so far. Here, we propose a higher-dimensional generalization the Sachdev-Ye-Kitaev (SYK) model and show that it exhibits MBL transition. The on bipartite lattice has $N$ Majorana fermions with SYK interactions each site $A$ sublattice $M$ free $B$ sublattice, where are large finite. For $r\ensuremath{\equiv}M/N<{r}_{c}=1$, describes diffusive metal exhibiting maximal chaos. Remarkably, its constant $D$ vanishes...
Inspired by the recent theoretical discovery of robust fractional topological phases without a magnetic field, we search for non-abelian quantum Hall effect in lattice models with flat bands. Through extensive numerical studies on Haldane model three-body hard-core bosons loaded into band, find convincing evidence stable ν=1 bosonic effect, characteristic threefold quasidegeneracy ground states torus, quantized Chern number, and spectrum gap. Moreover, two-quasihole also shows finite energy...