A5055967310- Topological Materials and Phenomena
- Quantum and electron transport phenomena
- Graphene research and applications
- Physics of Superconductivity and Magnetism
- Advanced Condensed Matter Physics
- Quantum many-body systems
- Surface and Thin Film Phenomena
- 2D Materials and Applications
- Surface Treatment and Residual Stress
- Magnetic properties of thin films
- Electronic and Structural Properties of Oxides
- Semiconductor Quantum Structures and Devices
- Metal and Thin Film Mechanics
- Metal Alloys Wear and Properties
- Advancements in Semiconductor Devices and Circuit Design
- Cold Atom Physics and Bose-Einstein Condensates
- Magnetic and transport properties of perovskites and related materials
- Quantum Information and Cryptography
- Molecular Junctions and Nanostructures
- Theoretical and Computational Physics
- Mechanical and Optical Resonators
- Atomic and Subatomic Physics Research
- High Entropy Alloys Studies
- Quantum, superfluid, helium dynamics
- Quantum Computing Algorithms and Architecture
Shanghai Advanced Research Institute
2024-2025
Peking University
2016-2025
Fudan University
2020-2025
Hefei University
2020-2025
Chinese Academy of Sciences
2001-2025
Guangzhou University
2022-2024
Hohai University
2024
Center for Theoretical Physics
2024
University of Chinese Academy of Sciences
2018-2023
Guangdong University of Technology
2021-2023
We report direct imaging of standing waves the nontrivial surface states topological insulator Bi2Te3 using a scanning tunneling microscope. The interference fringes are caused by scattering off Ag impurities and step edges on Bi2Te3(111) surface. By studying voltage-dependent wave patterns, we determine energy dispersion E(k), which confirms Dirac cone structure states. further show that, very different from conventional states, backscattering nonmagnetic is completely suppressed. absence...
High-quality Bi2Te3 films can be grown on Si by the state-of-art molecular beam epitaxy technique. In situ ARPES measurement reveals that as-grown are intrinsic topological insulators and single-Dirac-cone surface state develops at a thickness of two quintuple layers. The work opens new avenue for engineering materials based well-developed technology.
We report the direct observation of Landau quantization in Bi2Se3 thin films by using a low-temperature scanning tunneling microscope. In particular, we discovered zeroth level, which is predicted to give rise half-quantized Hall effect for topological surface states. The existence discrete levels (LLs) and suppression LLs impurities strongly support 2D nature These observations may eventually lead realization quantum insulators.
The tungsten ditelluride WTe${}_{2}$ semimetal is known for if its extremely large magnetoresistance. authors measure the angular dependence of this magnetoresistance and find that when magnetic field applied parallel to chains (along $a$ axis), very (as high as 1200% at 15 T 2 K) no longer exhibits a conventional quadratic but rather linear dependence.
We show that a one-dimensional tight-binding electron moving in slowly varying potential, ${V}_{n}=\ensuremath{\lambda}cos(\ensuremath{\alpha}{n}^{\ensuremath{\nu}})$, where $n$ is the site index and $0<\ensuremath{\nu}<1$, has mobility edge its spectrum provided $2\ensuremath{\lambda}$ smaller than total unperturbed bandwidth of system. study nature localized extended eigenstates this system as function $\ensuremath{\lambda}$ $\ensuremath{\nu}$.
We study the localization properties of one-dimensional nearest-neighbor tight-binding Schr\"odinger equation, ${\mathit{u}}_{\mathit{n}+1}$+${\mathit{u}}_{\mathit{n}\mathrm{\ensuremath{-}}1}$+${\mathit{V}}_{\mathit{n}}$${\mathit{u}}_{\mathit{n}}$=${\mathit{Eu}}_{\mathit{n}}$, where on-site potential ${\mathit{V}}_{\mathit{n}}$ is neither periodic (the ``Bloch'' case) nor random ``Anderson'' case), but aperiodic or pseudorandom. In particular, we consider in detail a class slowly varying...
The three-dimensional (3D) topological Dirac semimetal is a new phase of matter, viewed as the 3D analogy graphene with linear dispersion in momentum space. Here, we report angular dependent magnetotransport Cd3As2 single crystal and clearly show how Fermi surface evolves when tilting magnetic field. Remarkably, field lies [112] [44-1] axis, only oscillation period features present, however, system shows double oscillations applied along [1-10] direction. Moreover, at certain direction also...
We investigate the interplay between strong correlation and spin-orbit coupling in Kane-Mele-Hubbard model obtain qualitative phase diagram via variational cluster approach. identify, through an increase of Hubbard $U$, transition from topological band insulator to either spin liquid or easy-plane antiferromagnetic insulating phase, depending on strength coupling. A nontrivial evolution bulk bands quantum is also demonstrated.
We report comprehensive studies of the single crystal growth and electrical transport properties for various samples TaAs, first experimentally confirmed inversion symmetry-breaking Weyl semimetal. The parameters different are obtained through fitting two band model analysis Shubnikov de Haas oscillations. find that ratio factor lifetime to quantum is intensively enhanced when Fermi level approaches node. This result consistent with side-jump interpretation derived from a chirality-protected...
Atomically flat thin films of topological insulator Bi2Se3 have been grown on double-layer graphene formed 6H–SiC(0001) substrate by molecular beam epitaxy. By a combined study reflection high energy electron diffraction and scanning tunneling microscopy, we identified the Se-rich condition temperature criterion for layer-by-layer growth epitaxial films. The as-grown without doping exhibit low defect density 1.0±0.2×1011/cm2, become bulk at thickness ten quintuple layers, as revealed in situ...
The recent observation of superconducting state at atomic scale has motivated the pursuit exotic condensed phases in two-dimensional (2D) systems. Here we report on a phase two-monolayer crystalline Ga films epitaxially grown wide band-gap semiconductor GaN(0001). This exhibits hexagonal structure and only 0.552 nm thickness, nevertheless, brings about transition temperature Tc as high 5.4 K, confirmed by situ scanning tunneling spectroscopy, ex electrical magneto-transport magnetization...
Spin superfluid is a novel emerging quantum matter arising from the Bose-Einstein condensate (BEC) of spin-1 bosons. We demonstrate spin ground state in canted antiferromagnetic Cr2O3 thin film at low temperatures via nonlocal transport. A large enhancement signal observed below ~ 20 K, and it saturates 5 K down to 2 K. show that spins can propagate over very long distances (~ micro meters) such decreases slowly as spacing increases with an inverse relationship, which consistent theoretical...
In the semiclassical regime, chiral anomaly of Weyl semimetals is demonstrated by quadratic longitudinal magnetoconductivity. Recently planar Hall effect proposed in same systems, where conductivity depends quadratically on magnetic field. If cones are tilted, both chemical potential and anomalous velocity contribute a linear term to conductivities. We investigate electronic transport tilted semimetal presence an in-plane The results show that conductivities contain field besides terms...
Assembling GQDs on APF resin could improve separation and transfer efficiency of photogenerated electrons for H 2 O synthesis.
We study the nonequilibrium spin transport through a quantum dot coupled to magnetic electrodes. A formula for spin-dependent current is obtained and applied discuss linear conductance magnetoresistance in interacting regime. show that Kondo resonance correlation-induced splitting of levels may be systematically controlled by internal magnetization As result, when electrodes are parallel configuration, characterized two spin-resolved peaks. Furthermore, presence spin-flip process splits into three
We describe an optical system that allows for direct observation of the photonic Josephson effects in two weakly linked microcavities containing ultracold two-level atoms. show that, by moving atoms within one cavity, we could simulate analogous superconducting circuit and realize both alternating- direct-current (ac dc) effects. This provides a strategy constructing novel interference devices coherent photons enables new investigations effect many-body physics strongly coupled atom-cavity systems.
The dephasing effect on the quantum spin Hall (QSHE) is studied. Without dephasing, longitudinal resistance in a QSHE system exhibits plateaus. We find that these plateaus are robust against normal but fragile with dephasing. Thus, survive only mesoscopic samples. Moreover, increases linearly sample length insensitive to width. These characters excellent agreement recent experimental results [Science 318, 766 (2007)]. In addition, we define new also particular, any type of and therefore,...
This paper details an investigation of the influence different disorders in two-dimensional topological insulator systems. Unlike phase transitions to a Anderson induced by normal disorder, physical picture arises when bond disorder is considered. Using Born approximation theory, explanation given as why plays role transition than disorder. By comparing diagrams, conductance, conductance fluctuations, and localization length for systems with types consistent conclusion obtained. The results...
Quantum oscillations are usually the manifestation of underlying physical nature in condensed matter systems. Here, we report a new type log-periodic quantum ultraquantum three-dimensional topological materials. Beyond limit (QL), observe involving up to five oscillating cycles (five peaks and dips) on magnetoresistance high-quality single-crystal ZrTe 5 , virtually showing clearest feature discrete scale invariance (DSI). Further, theoretical analyses show that two-body quasi-bound states...
$\mathrm{HfT}{\mathrm{e}}_{5}$ is predicted to be a promising platform for studying topological phases. Here through an electrical transport study, we present observation of chiral anomaly and ultrahigh mobility in crystals. Negative magnetoresistivity observed when the external magnetic fields are parallel (B//E) quickly disappears once B deviates from direction E. Quantitative fitting further confirms as underlying physics. Moreover, by analyzing conductivity tensors longitudinal Hall...