Results for "H. Q. Xu"

total 110234took 0.15s
Spin Hall effect and zitterbewegung in an electron waveguideDec 20 2005Nov 08 2006We study spin-resolved probability distributions for electrons in a multichannel waveguide in the presence of a spin-orbit interaction. For a spin-polarized electron injection, a zitterbewegung pattern is predicted in the probability distribution of electrons ... More
Majorana fermions in topological insulator nanowires: from single superconducting nanowires to Josephson junctionsDec 07 2016Signatures of Majorana fermion bound states in one-dimensional topological insulator (TI) nanowires with proximity effect induced superconductivity are studied. The phase diagram and energy spectra are calculated for single TI nanowires and it is shown ... More
Extracting band structure characteristics of GaSb/InAs core-shell nanowires from thermoelectric propertiesOct 04 2016Mar 31 2017Nanowires with a GaSb core and an InAs shell (and the inverted structure) are interesting for studies of electron-hole hybridization and interaction effects due to the bulk broken band-gap alignment at the material interface. We have used eight-band $\mathbf{k\cdot ... More
k.p theory of freestanding narrow band gap semiconductor nanowiresMar 02 2016Jul 10 2016We report on a theoretical study of the electronic structures of freestanding nanowires made from narrow band gap semiconductors GaSb, InSb and InAs. The nanowires are described by the eight-band k.p Hamiltonians and the band structures are computed by ... More
Spin current diode based on an electron waveguide with spin-orbit interactionMay 08 2008We propose a spin current diode which can work even in a small applied bias condition (the linear-response regime). The prototypal device consists of a hornlike electron waveguide with Rashba spin-orbit interaction, which is connected to two leads with ... More
Majorana fermions in topological insulator nanowires: from single superconducting nanowires to Josephson junctionsDec 07 2016Mar 04 2017Signatures of Majorana fermion bound states in one-dimensional topological insulator (TI) nanowires with proximity effect induced superconductivity are studied. The phase diagram and energy spectra are calculated for single TI nanowires and it is shown ... More
Spin-3/2 physics of semiconductor hole nanowires: Valence-band mixing and tunable interplay between bulk-material and orbital bound-state spin splittingsDec 04 2008We present a detailed theoretical study of the electronic spectrum and Zeeman splitting in hole quantum wires. The spin-3/2 character of the topmost bulk-valence-band states results in a strong variation of subband-edge g factors between different subbands. ... More
Topological energy gaps in the [111]-oriented InAs/GaSb and GaSb/InAs core-shell nanowiresMar 03 2016The [111]-oriented InAs/GaSb and GaSb/InAs core-shell nanowires have been studied by the $8\times 8$ Luttinger-Kohn $\vec{k}\cdot\vec{p}$ Hamiltonian to search for non-vanishing fundamental gaps between inverted electron and hole bands. We focus on the ... More
Long-range adiabatic quantum state transfer through a linear array of quantum dotsJun 28 2012We introduce an adiabatic long-range quantum communication proposal based on a quantum dot array. By adiabatically varying the external gate voltage applied on the system, the quantum information encoded in the electron can be transported from one end ... More
Two-dimensional Mott variable-range hopping transport in a disordered MoS$_2$ nanoflakeJan 26 2018The transport characteristics of a disordered MoS$_2$ nanoflake in the insulator regime are studied by electrical and magnetotransport measurements. The layered MoS$_2$ nanoflake is exfoliated from a bulk MoS$_2$ crystal and the conductance $G$ and magnetoresistance ... More
Electronic structures of [111]-oriented free-standing InAs and InP nanowiresDec 14 2015We report on a theoretical study of the electronic structures of the [111]-oriented, free-standing, zincblende InAs and InP nanowires with hexagonal cross sections by means of an atomistic $sp^{3}s^{*} $, spin-orbit interaction included, nearest-neighbor, ... More
Empirical Parameterization of Nucleon-Nucleon Scattering Amplitude at High Energies for Glauber Calculations and Monte Carlo SimulationsMar 15 2016Jul 21 2016Parameterization of the nucleon-nucleon elastic scattering amplitude is needed for future experiments with nucleon and nuclear beams in the kinetic energy range 1 - 50 GeV/nucleon. The amplitude is used in Glauber calculations of various cross sections ... More
Lande-like formula for the g factors of hole-nanowire subband edgesMay 13 2008Jul 01 2008We have analyzed theoretically the Zeeman splitting of hole-quantum-wire subband edges. As is typical for any bound state, their g factor depends on both an intrinsic g factor of the material and an additional contribution arising from a finite bound-state ... More
Majorana bound states and subgap states in three-terminal topological superconducting nanowire-quantum dot hybrid devicesJan 26 2018Three-terminal topological superconducting nanowire (TSNW)-quantum dot (QD) hybrid junction devices are studied. The energy spectra and the wave functions of the subgap states are calculated as a function of the superconducting phase differences between ... More
Electronic transport properties of indolyl spirooxazine/merooxazine-based light-driven molecular switch: The effect of amino/nitro substituentsAug 07 2013By applying non-equilibrium Green's function formulation combined with first-principles density functional theory,we explore the electronic transport properties of indolinospironaphthoxazine (SO)/indolinomeronaphthoxazine (MO).The results indicate that ... More
Empirical Parameterization of Nucleon-Nucleon Elastic Scattering Amplitude at High Beam Momenta for Glauber Calculations and Monte Carlo SimulationsMar 15 2016Nov 05 2016A parameterization of the nucleon-nucleon elastic scattering amplitude is needed for future experiments with nucleon and nuclear beams in the beam momentum range of 2 -- 50 GeV/c/nucleon. There are many parameterizations of the amplitude at $P_{lab} >$ ... More
Electronic structures of free-standing nanowires made from indirect bandgap semiconductor gallium phosphideJun 08 2016We present a theoretical study of the electronic structures of freestanding nanowires made from gallium phosphide (GaP)--a III-V semiconductor with an indirect bulk bandgap. We consider [001]-oriented GaP nanowires with square and rectangular cross sections, ... More
Study of 0-$π$ phase transition in hybrid superconductor-InSb nanowire quantum dot devicesDec 30 2016Hybrid superconductor-semiconducting nanowire devices provide an ideal platform to investigating novel intragap bound states, such as the Andreev bound states (ABSs), Yu-Shiba-Rusinov (YSR) states, and the Majorana bound states. The competition between ... More
Unraveling electronic-structure features for metallic Na0.33CoO2 and charge-ordered Na0.5CoO2 by high-resolution electron energy-loss spectroscopyDec 07 2006Measurements by high-resolution electron energy-loss spectroscopy (HREELS) of NaxCoO2 reveal spectral features that differ remarkably between the metallic Na0.33CoO2 and the charge-ordered insulator Na0.5CoO2. Calculations by density functional theory ... More
Unified treatment of fluorescence and Raman scattering processes near metal surfacesMar 05 2004Dec 10 2004We present a general model study of surface-enhanced resonant Raman scattering and fluorescence focusing on the interplay between electromagnetic effects and the molecular dynamics. Our model molecule is placed close to two Ag nanoparticles, and has two ... More
Pd site doping effect on superconductivity in Nb2Pd0.76S5Feb 24 2016Pd site doping effect on superconductivity was investigated in quasi-one-dimensional superconductor Nb2(Pd1-xRx)0.76S5 (R=Ir, Ag) by measuring resistivity, magnetic susceptibility and Hall effect. It was found that superconducting transition temperature ... More
Effect of the tensor force on the charge-exchange spin-dipole excitations of 208PbMay 14 2010Jul 16 2010The charge-exchange spin-dipole (SD) excitations of 208Pb are studied by using a fully self-consistent Skyrme Hartree-Fock plus Random Phase Approximation (HF+RPA) formalism which includes the tensor interaction. It is found, for the first time, that ... More
Effect of Tensor Correlations on Gamow-Teller States in 90Zr and 208PbNov 04 2008Feb 24 2009The tensor terms of the Skyrme effective interaction are included in the self-consistent Hartree-Fock plus Random Phase Approximation (HF+RPA) model. The Gamow-Teller (GT) strength function of 90Zr and 208Pb are calculated with and without the tensor ... More
Static and Ultrafast Dynamics of Defects of SrTiO3 in LaAlO3/SrTiO3 HeterostructuresNov 03 2014A detailed defect energy level map was investigated for heterostructures of 26 unit cells of LaAlO3 on SrTiO3 prepared at a low oxygen partial pressure of 10-6 mbar. The origin is attributed to the presence of dominating oxygen defects in SrTiO3 substrate. ... More
Low-field magnetotransport in graphene cavity devicesFeb 25 2018Confinement and edge structures are known to play significant roles in electronic and transport properties of two-dimensional materials. Here, we report on low-temperature magnetotransport measurements of lithographically patterned graphene cavity nanodevices. ... More
Isoscalar giant monopole resonance in Sn isotopes using a quantum molecular dynamics modelAug 06 2013Dec 18 2013The isoscalar giant monopole resonance (ISGMR) in Sn isotopes and other nuclei is investigated in the framework of the isospin-dependent quantum molecular dynamics (IQMD) model. The spectrum of GMR is calculated by taking the root-mean-square (RMS) radius ... More
Coherent Charge Transport in Ballistic InSb Nanowire Josephson JunctionsApr 06 2016Hybrid InSb nanowire-superconductor devices are promising for investigating Majorana modes and topological quantum computation in solid-state devices. An experimental realisation of ballistic, phase-coherent superconductor-nanowire hybrid devices is a ... More
Transport signatures of relativistic quantum scars in a graphene cavitySep 23 2018We study a relativistic quantum cavity system realized by etching out from a graphene sheet by quantum transport measurements and theoretical calculations. The conductance of the graphene cavity has been measured as a function of the back gate voltage ... More
Accelerator Physics Issues in the BepciiJan 09 2004The Beijing Electron-Positron Collider (BEPC) has been running for both high energy physics (HEP) and synchrotron radiation (SR) researches since 1989. Good performance of BEPC accomplishes a lot of achievements in the tau-charm region over the past decade, ... More
Valley-dependent Brewster angles and Goos-Hanchen effect in strained grapheneAug 28 2010Sep 26 2011We demonstrate theoretically how local strains in graphene can be tailored to generate a valley polarized current. By suitable engineering of local strain profiles, we find that electrons in opposite valleys (K or K') show different Brewster-like angles ... More
Effects of tensor and $T=0$ pairing interactions on nuclear $β^+$/EC decayOct 04 2017The Hartree-Fock-Bogolyubov (HFB) plus proton-neutron quasiparticle random phase approximation (pnQRPA) approach based on Skyrme interaction is applied to study the nuclear $\beta^+$/EC decay for nuclei near the proton magic numbers $Z=$20, 28, and 50. ... More
Generating Searchable Public-Key Ciphertexts with Hidden Structures for Fast Keyword SearchDec 21 2015Existing semantically secure public-key searchable encryption schemes take search time linear with the total number of the ciphertexts. This makes retrieval from large-scale databases prohibitive. To alleviate this problem, this paper proposes Searchable ... More
Ab initio Gamow in-medium similarity renormalization group with resonance and continuumJun 23 2019We have developed a novel ab initio Gamow in-medium similarity renormalization group (Gamow IMSRG) in the complex-energy Berggren framework. The advanced Gamow IMSRG is capable of describing the resonance and nonresonant continuum properties of weakly ... More
Magnetic Properties of the low dimensional BaM$_2$Si$_2$O$_7$(M= Cu, Co, Mn) systemJul 18 2018We performed susceptibility, magnetization, specific heat, and single crystal neutron diffraction measurements on single crystalline BaMn$_2$Si$_2$O$_7$. Based on the results, we revisited its spin structure with a more accurate solution and constructed ... More
Combination of informational storage and logical processing based on an all-oxide asymmetric multiferroic tunnel junctionJun 24 2019Multiferroic tunnel junctions (MFTJs) have already been proved to be promising candidates for application in spintronics devices. The coupling between tunnel magnetoresistance (TMR) and tunnel electroresistance (TER) in MFTJs can provide four distinct ... More
Coherent transport in a linear triple quantum dot made from a pure-phase InAs nanowireJun 12 2017Jun 16 2017A highly tunable linear triple quantum dot (TQD) device is realized in a single-crystalline pure-phase InAs nanowire using a local finger gate technique. The electrical measurements show that the charge stability diagram of the TQD can be represented ... More
Structures of the reduced niobium oxides Nb12O29 and Nb22O54Aug 05 2007The crystal structure of Nb22O54 is reported for the first time, and the structure of orthorhombic Nb12O29 is reexamined, resolving previous ambiguities. Single crystal x-ray and electron diffraction were employed. These compounds were found to crystallize ... More
A Prototype of Upgrading Bepc Control SystemNov 13 2001Dec 13 2001We will use EPICS toolkit [1] to build a prototype for upgrading BEPC control system. The purposes are for the following three aspects: (1) Setup a network based distributed control system with EPICS. (2) Study some front-end control technology. (3) Merge ... More
Gate defined quantum dot realized in a single crystalline InSb nanosheetOct 03 2018Single crystalline InSb nanosheet is an emerging planar semiconductor material with potential applications in electronics, infrared optoelectronics, spintronics and topological quantum computing. Here we report on realization of a quantum dot device from ... More
Universal conductance fluctuations and phase-coherent transport in a semiconductor Bi$_2$O$_2$Se nanoplate with strong spin-orbit interactionMar 18 2019May 11 2019We report on phase-coherent transport studies of a Bi$_2$O$_2$Se nanoplate and on observation of universal conductance fluctuations and spin-orbit interaction induced reduction in fluctuation amplitude in the nanoplate. Thin-layered Bi$_2$O$_2$Se nanoplates ... More
Novel rapidity dependence of directed flow in high energy heavy ion collisionsAug 04 1999Jan 28 2000For high energy nucleus-nucleus collisions, we show that a combination of space-momentum correlations characteristic of radial expansion together with the correlation between the position of a nucleon in the nucleus and its stopping, results in a very ... More
Molecular Lines of 13 Glactic Infrared Bubble RegionsSep 10 2016We investigated the physical properties of molecular clouds and star formation processes around infrared bubbles which are essentially expanding HII regions. We performed observations of 13 galactic infrared bubble fields containing 18 bubbles. Five molecular ... More
BOUT++: a framework for parallel plasma fluid simulationsOct 31 2008Nov 05 2008A new modular code called BOUT++ is presented, which simulates 3D fluid equations in curvilinear coordinates. Although aimed at simulating Edge Localised Modes (ELMs) in tokamak X-point geometry, the code is able to simulate a wide range of fluid models ... More
Universal conductance fluctuations and phase-coherent transport in a semiconductor Bi$_2$O$_2$Se nanoplate with strong spin-orbit interactionMar 18 2019We report on phase-coherent transport studies of a Bi$_2$O$_2$Se nanoplate and on observation of universal conductance fluctuations and spin-orbit interaction induced reduction in fluctuation amplitude in the nanoplate. Thin-layered Bi$_2$O$_2$Se nanoplates ... More
Schottky barrier and contact resistance of InSb nanowire field effect transistorsMay 27 2016Understanding of the electrical contact properties of semiconductor nanowire (NW) field effect transistors (FETs) plays a crucial role in employing semiconducting NWs as building blocks for future nanoelectronic devices and in the study of fundamental ... More
Nonlinear PT-symmetric models bearing exact solutionsOct 28 2013We study the nonlinear Schr$\ddot{o}$dinger equation with a PT-symmetric potential. Using a hydrodynamic formulation and connecting the phase gradient to the field amplitude, allows for a reduction of the model to a Duffing or a generalized Duffing equation. ... More
Strain in Semiconductor Core-Shell NanowiresJun 02 2010We compute strain distributions in core-shell nanowires of zinc blende structure. We use both continuum elasticity theory and an atomistic model, and consider both finite and infinite wires. The atomistic valence force-field (VFF) model has only few assumptions. ... More
Brueckner-Hartree-Fock and its renormalized calculations for finite nucleiSep 09 2016We have performed self-consistent Brueckner-Hartree-Fock (BHF) and its renormalized theory to the structure calculations of finite nuclei. The $G$-matrix is calculated within the BHF basis, and the exact Pauli exclusion operator is determined by the BHF ... More
Disorder Influences the Quantum Critical Transport at a Superconductor to Insulator TransitionFeb 10 2015Oct 15 2015We isolated flux disorder effects on the transport at the critical point of the quantum magnetic field tuned Superconductor to Insulator transition (BSIT). The experiments employed films patterned into geometrically disordered hexagonal arrays. Spatial ... More
Strong spin-orbit interaction and magnetotransport in semiconductor Bi$_2$O$_2$Se nanoplatesJan 03 2018Semiconductor Bi$_2$O$_2$Se nanolayers of high crystal quality have been realized via epitaxial growth. These two-dimensional (2D) materials possess excellent electron transport properties with potential application in nanoelectronics. It is also strongly ... More
Strain distributions in lattice-mismatched semiconductor core-shell nanowiresMay 30 2010The authors study the elastic deformation field in lattice-mismatched core-shell nanowires with single and multiple shells. The authors consider infinite wires with a hexagonal cross section under the assumption of translational symmetry. The strain distributions ... More
The phase relation between sunspot numbers and soft X-ray flaresJan 04 2011Jan 07 2011To better understand long-term flare activity, we present a statistical study on soft X-ray flares from May 1976 to May 2008. It is found that the smoothed monthly peak fluxes of C-class, M-class, and X-class flares have a very noticeable time lag of ... More
Did the 2000 November 8 solar flare accelerate protons to >=40 GeV?Aug 08 2017It has been reported that a 5.7sigma directional muon excess coincident with the 2000 July 14 solar flare was registered by the L3 precision muon spectrometer [Ruiguang Wang, Astroparticle Phys., 31(2009) 149]. Using a same analysis method and similar ... More
Measurements of the spin-orbit interaction and Landé g factor in a pure-phase InAs nanowire double quantum dot in the Pauli spin-blockade regimeJul 23 2016We demonstrate direct measurements of the spin-orbit interaction and Land\'e g factors in a semiconductor nanowire double quantum dot. The device is made from a single-crystal pure-phase InAs nanowire on top of an array of finger gates on a Si/SiO$_2$ ... More
Resonances of unbound quantum many-body systems of nucleiSep 22 2018Resonance is a general phenomenon which can happen in classic or quantum systems. An unbound many-body quantum system can undergo a self-resonant process. It has long been a challenge how to describe unbound many-body quantum systems in resonances. In ... More
Transport studies of electron-hole and spin-orbit interaction in GaSb/InAsSb core-shell nanowire quantum dotsApr 20 2015We report low-temperature transport studies of parallel double quantum dots formed in GaSb/InAsSb core-shell nanowires. At negative gate voltages, regular patterns of Coulomb diamonds are observed in the charge stability diagrams, which we ascribe to ... More
Room-Temperature Ferromagnetic Topological Phase in CrO$_{2}$: From Tripe Fermions to Weyl FermionsNov 30 2017Ferromagnetic topological semimetals due to their band topology co-existing with intrinsic magnetization exerted important influences on early study of topological fermions. However, they have not been observed in experiments up to now. In this work, ... More
Interpretation of the "S-shaped" temperature dependence of luminescent peaks from semiconductorsFeb 12 2005The ``S-shape'' (decrease-increase-decrease) temperature dependence of luminescence peak shift from semiconductors is considered. A luminescence model for localized state ensemble was employed to interpret this anomalous temperature dependence of emission ... More
Superconductor to Insulator Transition Tuned by Random Gauge FieldsNov 25 2015Typically the disorder that alters the interference of particle waves to produce Anderson localization is potential scattering from randomly placed impurities. Here we show that disorder in the form of random gauge fields that act directly on particle ... More
Study of filamentation instability on the divergence of ultraintense laser-driven electronsOct 14 2016Generation of relativistic electron (RE) beams during ultraintense laser pulse interaction with plasma targets is studied by collisional particle-in-cell (PIC) simulations. Strong magnetic field with transverse scale length of several local plasma skin ... More
Phonon number fluctuations in Debye model of solidJan 31 2019Apr 27 2019The phonon number fluctuations in the Debye model of solid are calculated and are demonstrated to be proportional to the temperature cubed at low temperature, similar to the celebrated Debye's law of the heat capacity. For a fixed number of atoms, the ... More
Quantized conductance and its correlation to the supercurrent in a nanowire connected to superconductorsJun 03 2013We report conductance and supercurrent of InAs nanowires coupled to Al-superconducting electrodes with short channel lengths and good Ohmic contacts. The nanowires are suspended 15\,nm above a local gate electrode. The charge density in the nanowires ... More
An accretion disk model for periodic timing variations of pulsarsJun 24 2003The long-term, highly periodic and correlated variations in both the pulse shape and the rate of slow-down of two isolated pulsars (PSRs) PSR B1828-11 and PSR B1642-03 were discovered recently. This phenomenon may provide evidence for "free precession" ... More
Sodium Ion Ordering in NaxCoO2Mar 08 2004The layered sodium cobalt oxide NaxCoO2 is studied by electron diffraction for a wide range of sodium contents, 0.15<x<0.75. An extensive series of ordered Na ion-Na vacancy superlattices is found beyond the simple hexagonal average structure. The most ... More
Superconductivity in Mg10Ir19B16Aug 26 2006Mg10Ir19B16, a previously unreported compound in the Mg-Ir-B chemical system, is found to be superconducting at temperatures near 5 K. The fact that the compound exhibits a range of superconducting temperatures between 4 and 5 K suggests that a range ... More
Control System of the BepciiNov 21 2001Recently the Chinese Academy of Sciences has chosen BEPCII as the future development of the BEPC, i.e. upgrade of both the machine and detector. The luminosity of the machine is expected to increase to 1.0x1033cm-2s-1. The project will be started at the ... More
A model for luminescence of localized state ensembleNov 05 2004A distribution function for localized carriers, $f(E,T)=\frac{1}{e^{(E-E_a)/k_BT}+\tau_{tr}/\tau_r}$, is proposed by solving a rate equation, in which, electrical carriers' generation, thermal escape, recapture and radiative recombination are taken into ... More
On Peak Age of Information in Data Preprocessing enabled IoT NetworksJan 27 2019Internet of Things (IoT) has been emerging as one of the use cases permeating our daily lives in 5th Generation wireless networks, where status update packages are usually required to be timely delivered for many IoT based intelligent applications. Enabling ... More
Electronic structures of [001]- and [111]-oriented InSb and GaSb free-standing nanowiresFeb 26 2015We report on a theoretical study of the electronic structures of InSb and GaSb nanowires oriented along the [001] and [111] crystallographic directions. The nanowires are described by atomistic, spin-orbit inteaction included, tight-binding models, and ... More
Conductivity of LaAlO/SrTiO3 Interfaces made by Sputter DepositionNov 21 2011We have investigated the properties of interfaces between LaAlO3 films grown on SrTiO3 substrates singly terminated by TiO2. We used RF sputtering in a high-pressure oxygen atmosphere. The films are smooth, with flat surfaces. Transmission Electron Microscopy ... More
Role of T=0 pairing in Gamow-Teller states in N=Z nucleiNov 21 2012Gamow-Teller (GT) states in N=Z nuclei with the mass number A from 48 to 64 are studied by using Hartree-Fock-Bogoliubov + quasi-particle random phase approximation (HFB+QRPA) with Skyrme interactions. The isoscalar spin-triplet (T=0,S=1) pairing interaction ... More
Discontinuous Galerkin method for fractional convection-diffusion equationsApr 22 2013We propose a discontinuous Galerkin method for convection-subdiffusion equations with a fractional operator of order $\alpha (1<\alpha<2)$ defined through the fractional Laplacian. The fractional operator of order $\alpha$ is expressed as a composite ... More
Preparation and transport properties of non-hydrated Na$_{0.5}$CoO$_2$ single crystalsDec 12 2004Single crystals of Na$_{0.5}$CoO$_2$ were obtained through a flux method followed by de-intercalation of sodium. The Na$_{0.5}$CoO$_2$ samples were found to be vulnerable to water in the air and a hydration process in which H$_2$O molecules fill oxygen ... More
Andreev reflection and spin polarization measurement of Co/YBCO junctionApr 01 2008Mar 24 2009We report temperature dependent Andreev reflection measurements of Co/ Y$_{1}$Ba$_{2}$Cu$_{3}$O$_{7-\delta}$ (YBCO) heterostructure samples with junction areas of 1 $\mu$m diameter. Modelling of the 5-70 K conductivity data according to a modified Blonder-Tinkham-Klapwijk ... More
Electronic structure and electron energy-loss spectra of Sr0.35CoO2Dec 07 2006The electronic structure of Sr0.35CoO2, structurally analogous to the layered NaxCoO2, has been evaluated using the local spin density approximation (LSDA). We find that evident c-dispersions appear in both the e'g and a1g Co-derived bands, demonstrating ... More
Plaquette order and deconfined quantum critical point in the spin-1 bilinear-biquadratic Heisenberg model on the honeycomb latticeMay 13 2011Apr 23 2012We have precisely determined the ground state phase diagram of the quantum spin-1 bilinear-biquadratic Heisenberg model on the honeycomb lattice using the tensor renormalization group method. We find that the ferromagnetic, ferroquadrupolar, and a large ... More
Gate tunable parallel double quantum dot in InAs double-nanowire junctionsMar 10 2017We report fabrication and measurement of a device where closely-placed two parallel InAs nanowires (NWs) are contacted by source and drain normal metal electrodes. Established technique includes selective deposition of double nanowires onto a previously ... More
Electronic structure of the BaTi$_2$As$_2$O parent compound of the titanium based oxypnictide superconductorJan 29 2014The electronic structure of BaTi2As2O, a parent compound of the newly discovered titanium-based oxypnictide superconductors, is studied by angle-resolved photoemission spectroscopy. The electronic structure shows multi-orbital nature and possible three-dimensional ... More
Evolution of Fermi surface and normal-state gap in chemically substituted cuprates Bi$_{2}$Sr$_{2-x}$Bi$_{x}$CuO$_{6+δ}$Jun 06 2008We have performed a systematic angle-resolved photoemission study of chemically substituted cuprates Bi$_{2}$Sr$_{2-x}$Bi$_{x}$CuO$_{6+\delta}$. We observed that the Fermi surface area shrinks linearly with Bi substitution content $x$, reflecting the ... More
Highly anisotropic and two-fold symmetric superconducting gap in nematically ordered FeSe$_{0.93}$S$_{0.07}$Mar 16 2016FeSe exhibits a novel ground state in which superconductivity coexists with a nematic order in the absence of any long-range magnetic order. Here we report an angle-resolved photoemission study on the superconducting gap structure in the nematic state ... More
Temperature-induced band selective localization and coherent-incoherent crossover in single-layer FeSe/Nb:BaTiO3 /KTaO3Apr 22 2016Iron chalcogenide superconductors are multi-band systems with strong electron correlations. Here we use angle-resolved photoemission spectroscopy to study band dependent correlation effects in single-layer FeSe/Nb:BaTiO3/KTaO3, a new iron chalcogenide ... More
An Intense $γ$-ray Beam Line of 10 MeV Order Based on Compton BackscatteringOct 24 2006Shanghai Laser Electron Gamma Source, a $\gamma$-ray beam line of 10MeV order was proposed recently. The beam line is expected to generate $\gamma$-ray with maximum energy of 22MeV by backward Compton scattering between CO$_2$ laser and electron in the ... More
Measurements of strain and bandgap of coherently epitaxially grown wurtzite InAsP-InP core-shell nanowiresApr 12 2019We report on experimental determination of the strain and bandgap of InAsP in epitaxially grown InAsP-InP core-shell nanowires. The core-shell nanowires are grown via metal-organic vapor phase epitaxy. The as-grown nanowires are characterized by transmission ... More
Signatures of Wigner Localization in Epitaxially Grown NanowiresOct 25 2010Jan 31 2011It was predicted by Wigner in 1934 that the electron gas will undergo a transition to a crystallized state when its density is very low. Whereas significant progress has been made towards the detection of electronic Wigner states, their clear and direct ... More
Topologically entangled Rashba-split bands on the grey arsenic surfaceAug 10 2016Rashba-split states are discovered on the surfaces of many semi-infinite single crystals. They are generally explained based on the Rashba theory, considering spin-orbit coupling (SOC) and inversion symmetry breaking on the surface. Here we investigate ... More
The unique electronic structure of Ca10(Pt4As8)(Fe2-xPtxAs2)5 with metallic Pt4As8 layersAug 13 2013We studied the low-lying electronic structure of the newly discovered iron-platinum-arsenide superconductor, Ca10(Pt4As8)(Fe2-xPtxAs2)5 (Tc=22 K) with angle-resolved photoemission spectroscopy. We found that the Pt4As8 layer contributes to a small electron-like ... More
Formation of Long Single Quantum Dots in High Quality InSb Nanowires Grown by Molecular Beam EpitaxyAug 13 2015We report on realization and transport spectroscopy study of single quantum dots (QDs) made from InSb nanowires grown by molecular beam epitaxy (MBE). The nanowires employed are 50-80 nm in diameter and the QDs are defined in the nanowires between the ... More
Charge transport in InAs nanowire Josephson junctionsNov 07 2013Jun 27 2014We present an extensive experimental and theoretical study of the proximity effect in InAs nanowires connected to superconducting electrodes. We fabricate and investigate devices with suspended gate-controlled nanowires and nonsuspended nanowires, with ... More
Discriminating cosmic muons and radioactivity using a liquid scintillation fiber detectorAug 30 2016Mar 06 2017In the case of underground experiments for neutrino physics or rare event searches, the background caused by cosmic muons contributes significantly and therefore must be identified and rejected. We proposed and optimized a new detector using liquid scintillator ... More
In-Plane Magnetic Anisotropy In RF Sputtered Fe-N Thin FilmsAug 14 2003We have fabricated Fe(N) thin films with varied N2 partial pressure and studied the microstructure, morphology, magnetic properties and resistivity by using X-ray diffraction, atomic force microscopy, transmission electron microscopy, vibrating-sample ... More
Transmutation prospect of long-lived nuclear waste induced by high-charge electron beam from laser plasma acceleratorMay 16 2017Photo-transmutation of long-lived nuclear waste induced by high-charge relativistic electron beam (e-beam) from laser plasma accelerator is demonstrated. Collimated relativistic e-beam with a high charge of approximately 100 nC is produced from high-intensity ... More
Charge transport and electron-hole asymmetry in low-mobility graphene/hexagonal boron nitride heterostructuresFeb 09 2018Graphene/hexagonal boron nitride (G/$h$-BN) heterostructures offer an excellent platform for developing nanoelectronic devices and for exploring correlated states in graphene under modulation by a periodic superlattice potential. Here, we report on transport ... More
Topologically entangled Rashba-split Shockley states on the surface of grey arsenicAug 10 2016Feb 06 2017We discover a pair of spin-polarized surface bands on the (111) face of grey arsenic by using angle-resolved photoemission spectroscopy (ARPES). In the occupied side, the pair resembles typical nearly-free-electron Shockley states observed on noble-metal ... More
Kondo Correlation Induced Low-Field Magnetoresistance Anomalies in InSb Nanowire Josephson Quantum Dot DevicesAug 21 2018We report the observation of sharp suppression of superconductivity-induced zero-bias conductance peaks at low magnetic fields in InSb nanowire Josephson quantum dot devices. With multiple gates, the quantum dot devices can be tuned to the Kondo-superconductivity ... More
Experimental simulation of next-nearest-neighbor Heisenberg chain with photonic crystal waveguide arrayNov 08 2016Next-nearest-neighbor Heisenberg chain plays important roles in solid state physics, such as predicting exotic electric properties of two-dimensional materials or magnetic properties of organic compounds. Direct experimental studies of the many-body electron ... More
Multi-pion Bose-Einstein Correlation effects on three-pion interferometryApr 21 1998Multi-pion correlations effect on three-pion interferometry is studied. It is shown that multi-pion correlations decrease both the apparent radius of the source and the coherent source parameter derived from three-pion interferometry. The data of OPAL ... More
Cosmic Ray Protons Illuminate Dark Matter AxionsAug 16 2011Cosmic ray protons propagating in a spatially-homogeneous but time-dependent field of axions or axion-like particles (ALPs) emit photons in a way that is reminiscent of Cherenkov radiation by charged particles in a preferred background. We compute the ... More
Anisotropic Pauli spin-blockade effect and spin-orbit interaction field in an InAs nanowire double quantum dotMar 20 2018We report on experimental detection of the spin-orbit interaction field in an InAs nanowire double quantum dot device. In the spin blockade regime, leakage current through the double quantum dot is measured and is used to extract the effects of spin-orbit ... More
Superconductivity at 2.3 K in the misfit compound (PbSe)1.16(TiSe2)2Jun 30 2010The structural misfit compound (PbSe)1.16(TiSe2)2 is reported. It is a superconductor with a Tc of 2.3 K. (PbSe)1.16(TiSe2)2 derives from a parent compound, TiSe2, which shows a charge density wave transition and no superconductivity. The crystal structure, ... More
Weak antilocalization and electron-electron interaction in coupled multiple-channel transport in a Bi$_2$Se$_3$ thin filmDec 14 2015Electron transport properties of a topological insulator Bi$_2$Se$_3$ thin film are studied in Hall-bar geometry. The film with a thickness of 10 nm is grown by van der Waals epitaxy on fluorophlogopite mica and Hall-bar devices are fabricated from the ... More