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Ferroelectricity driven by the non-centrosymmetric magnetic ordering in multiferroic TbMn_2O_5: a first-principles studyApr 23 2007Oct 24 2007The ground state structural, electronic and magnetic properties of multiferroic TbMn$_2$O$_5$ are investigated via first-principles calculations. We show that the ferroelectricity in TbMn$_2$O$_5$ is driven by the non-centrosymmetric magnetic ordering, ... More

Prevention of dissipation with two particlesDec 02 1997An error prevention procedure based on two-particle encoding is proposed for protecting an arbitrary unknown quantum state from dissipation, such as phase damping and amplitude damping. The schemes, which exhibits manifestation of the quantum Zeno effect, ... More

Two non-orthogonal states can be cloned by a unitary-reduction processApr 10 1997We show that, there are physical means for cloning two non-orthogonal pure states which are secretly chosen from a certain set $% \$={ | \Psi_0 > , | \Psi_1 > }$. The states are cloned through a unitary evolution together with a measurement. The cloning ... More

Alternative approach to electromagnetic field quantization in nonlinear and inhomogeneous mediaDec 01 1996Feb 02 1998A simple approach is proposed for the quantization of the electromagnetic field in nonlinear and inhomogeneous media. Given the dielectric function and nonlinear susceptibilities, the Hamiltonian of the electromagnetic field is determined completely by ... More

Cooperative loss and decoherence in quantum computation and commuicationJan 16 1997Cooperative effects in the loss (the amplitude damping) and decoherence (the phase damping) of the qubits (two-state quantum systems) due to the inevitable coupling to the same environment are investigated. It is found that the qubits undergo the dissipation ... More

Reducing decoherence in quantum computer memory with all quantum bits coupling to the same environmentNov 29 1996Feb 02 1998Decoherence in quantum computer memory due to the inevitable coupling to the external environment is examined. We take the assumption that all quantum bits (qubits) interact with the same environment rather than the assumption of separate environments ... More

First-principles study of the lattice and electronic structures of TbMn$_2$O$_5$Nov 16 2007The structural, electronic and lattice dielectric properties of multiferroic TbMn$_2$O$_5$ are investigated using density functional theory within the generalized gradient approximation (GGA). We use collinear spin approximations and ignore the spin-orbit ... More

Reducing spatially correlated noise and decoherence with quantum error correcting codesNov 22 1998It is shown that the noise process in quantum computation can be described by spatially correlated decoherence and dissipation. We demonstrate that the conventional quantum error correcting codes correcting for single-qubit errors are applicable for reducing ... More

Quantum error avoiding codes versus quantum error correcting codesSep 19 1998A general theory of quantum error avoiding codes is established, and new light is shed on the relation between quantum error avoiding and correcting codes. Quantum error avoiding codes are found to be a special type of highly degenerate quantum error ... More

Probabilistic cloning and identification of linearly independent quantum statesApr 27 1998We construct a probabilistic quantum cloning machine by a general unitary-reduction operation. With a postselection of the measurement results, the machine yields faithful copies of the input states. It is shown that the states secretly chosen from a ... More

Perturbative expansions for the fidelities and spatially correlated dissipation of quantum bitsJun 10 1997Feb 02 1998We construct generally applicable short-time perturbative expansions for some fidelities, such as the input-output fidelity, the entanglement fidelity, and the average fidelity. Successive terms of these expansions yield characteristic times for the damping ... More

Pulse controlled noise suppressed quantum computationJul 26 1998To make arbitrarily accurate quantum computation possible, practical realization of quantum computers will require suppressing noise in quantum memory and gate operations to make it below a threshold value. A scheme based on realistic quantum computer ... More

Optimal quantum codes for preventing collective amplitude dampingApr 06 1998Collective decoherence is possible if the departure between quantum bits is smaller than the effective wave length of the noise field. Collectivity in the decoherence helps us to devise more efficient quantum codes. We present a class of optimal quantum ... More

Correlations in interference and diffractionJun 18 1997Quantum formalism of Fraunhofer diffraction is obtained. The state of the diffraction optical field is connected with the state of the incident optical field by a diffraction factor. Based on this formalism, correlations of the diffraction modes are calculated ... More

Theory of strain tunning exction coupling in self-assembled InAs/GaAs quantum dotsJan 13 2014We derive analytically the change of exciton fine structure splitting (FSS) under the external stresses in the self-assembled InAs/GaAs quantum dots using the Bir-Pikus model. We find that the FSS change is mainly due to the strain induced valence bands ... More

Molecular-spin dynamics study of electromagnons in multiferroic RMn$_2$O$_5$Jul 18 2011We investigate the electromagnon in magnetoferroelectrics RMn$_2$O$_5$ using combined molecular-spin dynamics simulations. We identify the origin of the electromagnon modes observed in the optical spectra and reproduce the most salient features of the ... More

Slow Exciton Spin Relaxation in Single Self-Assembled In$_{1-x}$Ga$_x$As/GaAs Quantum DotsOct 10 2013We calculate the acoustic phonon-assisted exciton spin relaxation in single self-assembled In$_{1-x}$Ga$_x$As/GaAs quantum dots using an atomic empirical pseudopotential method. We show that the transition from bright to dark exciton states is induced ... More

Quantum Non-Demolition Bell State Measurement and N-party GHZ State Preparation in Quantum DotNov 28 2005Sep 27 2006By exploiting the fermionic qubit parity measurement, we present a scheme to realize quantum non-demolition (QND) measurement of Bell-states and generate n-party GHZ state in quantum dot. Compared with the original protocol, the required electron transfer ... More

Remote Preparation of Mixed States via Noisy EntanglementMar 09 2005We present a practical and general scheme of remote preparation for pure and mixed state, in which an auxiliary qubit and controlled-NOT gate are used. We discuss the remote state preparation (RSP) in two important types of decoherent channel (depolarizing ... More

Methods for linear optical quantum Fredkin gateApr 07 2008We consider the realization of quantum Fredkin gate with only linear optics and single photons. First we construct a heralded Fredkin gate using four heralded controlled-not (CNOT) gates. Then we simplify this method to a post-selected one utilizing only ... More

Exciton polarization, fine structure splitting and quantum dot asymmetry under uniaxial stressDec 13 2010May 03 2011We derive a general relation between the fine structure splitting (FSS) and the exciton polarization angle of self-assembled quantum dots (QDs) under uniaxial stress. We show that the FSS lower bound under external stress can be predicted by the exciton ... More

Size consistency of tensor network methods for quantum many-body systemsApr 23 2013Recently developed tensor network methods demonstrate great potential for addressing the quantum many-body problem, by constructing variational spaces with polynomially, instead of exponentially, scaled parameters. Constructing such an efficient tensor ... More

Efficient numerical method to calculate three-tangle of mixed statesDec 31 2009We demonstrate an efficient numerical method to calculate three-tangle of general mixed states. We construct a "energy function" (target function) for the three-tangle of the mixed state under certain constrains. The "energy function" (target function) ... More

First-principles modeling of multferroic RMn$_2$O$_5$Jul 25 2009Dec 21 2009We investigate the phase diagrams of RMn$_2$O$_5$ via a first-principles effective-Hamiltonian method. We are able to reproduce the most important features of the complicated magnetic and ferroelectric phase transitions. The calculated polarization as ... More

Origin of ferroelectricity in high $T_c$ magnetic ferroelectric CuOJul 14 2010May 07 2012"Magnetic ferroelectric" has been found in a wide range of spiral magnets. However, these materials all suffer from low critical temperatures, which are usually below 40 K, due to strong spin frustration. Recently, CuO has been found to be multiferroic ... More

Decoherence effects on the quantum spin channelsMar 25 2006Jun 11 2006An open ended spin chain can serves as a quantum data bus for the coherent transfer of quantum state information. In this paper, we investigate the efficiency of such quantum spin channels which work in a decoherence environment. Our results show that, ... More

Vortex-core structure in a mixture of Bose and Fermi superfluidsJan 23 2017Jun 22 2017We study a single quantized vortex in the fermionic component of a mixture of Fermi superfluid and Bose-Einstein condensate. As the density ratio between the boson and the fermion components is tuned, we identify a transition in the vortex-core structure, ... More

Optimal entanglement purifying via entanglement swappingMay 30 2000It is known that entanglement swapping can be used to realize entanglement purifying. By this way, two particles belong to different non-maximally entangled pairs can be projected probabilisticly to a maximally entangled state or to a less entangled state. ... More

Heating and Cooling in Adiabatic Mixing processMay 28 2010Feb 18 2011We study the effect of interaction on the temperature change in the process of adiabatic mixing two components of fermi gases by the real-space Bogoliubov-de Gennes (BdG) method. We find that in the process of adiabatic mixing, the competition of the ... More

Characterizing Nonlocal Correlations via Universal Uncertainty RelationsMay 24 2017Oct 22 2017Characterization and certification of nonlocal correlations is one of the the central topics in quantum information theory. In this work, we develop the detection methods of entanglement and steering based on the universal uncertainty relations and fine-grained ... More

First-principles study of the spin-lattice coulpling in spin frustrated DyMn$_2$O$_5$Jul 03 2008Oct 12 2008The lattice dynamic properties and spin-phonon coupling in DyMn$_2$O$_5$ are studied by using the density-functional theory. The calculated phonon frequencies are in very good agreement with experiments. We then compare the phonon modes calculated from ... More

Quantum key distribution via quantum encryptionNov 09 2000Jul 10 2001A quantum key distribution protocol based on quantum encryption is presented in this Brief Report. In this protocol, the previously shared Einstein-Podolsky-Rosen pairs act as the quantum key to encode and decode the classical cryptography key. The quantum ... More

Comment on "Quantum key distribution without alternative measurements"Sep 11 2000In a recent paper [A. Cabello, Phys. Rev. A 61, 052312 (2000)], a quantum key distribution protocol based on entanglement swapping was proposed. However, in this comment, it is shown that this protocol is insecure if Eve use a special strategy to attack. ... More

Quantum authentication using entangled stateAug 09 2000Aug 16 2000A scheme of quantum authentication is presented. Two parties share Einstein-Podolsky-Rosen (EPR) pairs previously as the authentication key which servers as encoder and decoder. The authentication is accomplished with local controlled-NOT operations and ... More

Temperature Dependent Empirical Pseudopotential Theory For Self-Assembled Quantum DotsMar 13 2012We develop a temperature dependent empirical pseudopotential theory to study the electronic and optical properties of self-assembled quantum dots (QDs) at finite temperature. The theory takes the effects of both lattice expansion and lattice vibration ... More

Quantum random walk in periodic potential on a lineOct 11 2012Oct 15 2012We investigated the discrete-time quantum random walks on a line in periodic potential. The probability distribution with periodic potential is more complex compared to the normal quantum walks, and the standard deviation $\sigma$ has interesting behaviors ... More

Quantum key distribution using different-frequency photonsJun 08 2000In this paper, we present a scheme for quantum key distribution, in which different-frequency photons are used to encode the key. Thses different-frequency photons are produced by an acoustic-optical modulator and two kinds of narrow filters . This scheme ... More

Average position in quantum walks with a U(2) coinOct 11 2012We investigated discrete-time quantum walks with an arbitary unitary coin. Here we discover that the average position $<x> =\max(<x> \sin(\alpha+\gamma)$, while the initial state is $1/\sqrt{2}(\mid0L>+i\mid0R>)$. We prove the result and get some symmetry ... More

The origin of hyperferroelectricity in Li$B$O$_3$ ($B$=V, Nb, Ta, Os)Oct 23 2015The electronic and structural properties of Li$B$O$_3$ ($B$=V, Nb, Ta, Os) are investigated via first-principles methods. We show that Li$B$O$_3$ belong to the recently proposed hyperferroelectrics, i.e., they all have unstable longitudinal optic phonon ... More

Apply current exponential de Finetti theorem to realistic quantum key distributionSep 16 2008Jan 18 2009In the realistic quantum key distribution (QKD), Alice and Bob respectively get a quantum state from an unknown channel, whose dimension may be unknown. However, while discussing the security, sometime we need to know exact dimension, since current exponential ... More

Conquer the fine structure splitting of excitons in self-assembled InAs/GaAs quantum dots via combined stressesJun 06 2012Eliminating the fine structure splitting (FSS) of excitons in self-assembled quantum dots (QDs) is essential to the generation of high quality entangled photon pairs. It has been shown that the FSS has a lower bound under uniaxial stress. In this letter, ... More

Manipulating the frequency entangled states by acoustic-optical-modulatorMay 17 2000In this paper, we describe how to realize conditional frequency entanglement swapping and to produce probabilisticly a three-photon frequency entangled state from two pairs of frequency entangled states by using an Acoustic-Optical-Modulator. Both schemes ... More

Qunatum Parrondo's games constructed by quantum random walkMar 27 2013We construct a Parrondo's game using discrete time quantum walks. Two lossing games are represented by two different coin operators. By mixing the two coin operators $U_{A}(\alpha_{A},\beta_{A},\gamma_{A})$ and $U_{B}(\alpha_{B},\beta_{B},\gamma_{B})$, ... More

Nonclassicality of quantum excitation of classical coherent field in photon loss channelJan 05 2007We investigate the nonclassicality of photon-added coherent states in the photon loss channel by exploring the entanglement potential and negative Wigner distribution. The total negative probability defined by the absolute value of the integral of the ... More

Unconventional superfluid in a two-dimensional Fermi gas with anisotropic spin-orbit coupling and Zeeman fieldsNov 25 2012Feb 04 2013We study the phase diagram of a two-dimensional ultracold Fermi gas with the synthetic spin-orbit coupling (SOC) that has recently been realized at NIST. Due to the coexistence of anisotropic SOC and effective Zeeman fields in the NIST scheme, the system ... More

Monogamy Relation in No-disturbance TheoriesMay 17 2016The monogamy is a fundamental property of Bell nonlocality and contextuality. In this article, we studied the $n$-cycle noncontextual inequalities and generalized CHSH inequalities in detail and found the sufficient conditions for those inequalities to ... More

Width of the confinement-induced resonance in a quasi-one-dimensional trap with transverse anisotropyFeb 19 2017Nov 23 2017We theoretically study the width of the s-wave confinement-induced resonance (CIR) in quasi-one-dimensional atomic gases under tunable transversely anisotropic confinement. We find that the width of the CIR can be tuned by varying the transverse anisotropy. ... More

Influence of unsymmetrical periodicity on extraordinary transmission through periodic arrays of subwavelength holesNov 29 2006Apr 25 2007Quadrate hole array is explored to study the influence of unsymmetrical periodicity on extraordinary optical transmission through periodic arrays of subwavelength holes. It is found that the transmission efficiency of light and the ratio between transmission ... More

Plasmon assisted transmission of high dimensional orbital angular momentum entangled stateMar 24 2006Dec 07 2006We present an experimental evidence that high dimensional orbital angular momentum entanglement of a pair of photons can be survived after a photon-plasmon-photon conversion. The information of spatial modes can be coherently transmitted by surface plasmons. ... More

Generation of quantum-dot cluster states with superconducting transmission line resonatorApr 20 2008Jan 20 2009We propose an efficient method to generate cluster states in spatially separated double quantum dots with a superconducting transmission line resonator (TLR). When the detuning between the double-dot qubits transition frequency and the frequency of the ... More

Effect of Quantum Point Contact Measurement on Electron Spin State in Quantum DotAug 05 2008Jan 09 2009We study the time evolution of two electron spin states in a double quantum-dot system, which includes a nearby quantum point contact (QPC) as a measurement device. We obtain that the QPC measurement induced decoherence is in time scales of microsecond. ... More

Orbital angular momentum of the down converted photonsSep 04 2003We calculate the relative amplitude of orbital angular momentum (OAM) entangled photon pairs from the spontaneous parametric down conversion. The results show that the amplitude depends on both the two Laguerre indices l, p. We also discuss the influences ... More

Entanglement of the Hermite-Gaussian modes states of photonsJul 28 2004May 30 2005We found that the Hermit-Gaussian(HG) modes of the down converted beams from the spontaneous parametric down conversion are quasi-conserved and the generated photon pairs are HG modes entangled for some special cases. This is valuable for either the investigation ... More

Coulomb blockade in graphene quantum dotsNov 15 2009We study the conductance spectrum of graphene quantum dots, both single and multiple cases. The single electron tunneling phenomenon is investigated and the periodicity, amplitude and line shape of the Coulomb blockade oscillations at low temperatures ... More

Substrate Modulated Graphene Quantum DotOct 25 2009We propose a new method to use gapped graphene as barrier to confine electrons in gapless graphene and form a good quantum dot, which can be realized on an oxygen-terminated $SiO_{2}$ substrate partly H-passivated. In particular, we use ferromagnetic ... More

Dispersive Coupling Between the Superconducting Transmission Line Resonator and the Double Quantum DotsFeb 10 2008May 30 2008Realization of controllable interaction between distant qubits is one of the major problems in scalable solid state quantum computing. We study a superconducting transmission line resonator (TLR) as a tunable dispersive coupler for the double-dot molecules. ... More

Ultrafast Manipulation of a Double Quantum Dot via Lyapunov Control MethodJan 12 2014For a double quantum dot (DQD) system, here we propose alternative ultrafast manipulate approach: Lyapunov control method, to transfer the state from R to L on the picosecond scale, orders of magnitude faster and transfer probability higher than the previously ... More

Spatial mode properties of plasmon assisted transmissionMar 03 2006Sep 11 2006Orbital angular momentum of photons is explored to study the spatial mode properties of plasmon assisted transmission process. We found that photons carrying different orbital angular momentums have different transmission efficiencies, while the coherence ... More

Efficient coupling between dielectric waveguide modes and exterior plasmon whispering gallery modesOct 21 2013Inefficient coupling between dielectric guided mode and plasmon mode has been overlooked in the past. The mechanism in it is essentially different from the conventional coupling between dielectric modes. Based on qualitative theoretical analysis, we proposed ... More

64-Qubit Quantum Circuit SimulationFeb 20 2018Jul 12 2018Classical simulations of quantum circuits are limited in both space and time when the qubit count is above 50, the realm where quantum supremacy reigns. However, recently, for the low depth circuit with more than 50 qubits, there are several methods of ... More

Enhanced absorption microscopy with correlated photon pairsJul 04 2018By harnessing the quantum states of light for illumination, precise phase and absorption estimations can be achieved with precision beyond the standard quantum limit. Despite their significance for precision measurements, quantum states are fragile in ... More

Engineering of multi-dimensional entangled states of photon pairs using hyper-entanglementFeb 01 2005Multi-dimensional entangled states have been proven to be more powerful in some quantum information process. In this paper, down-converted photons from spontaneous parametric down conversion(SPDC) are used to engineer multi-dimensional entangled states. ... More

Error-compensation measurements on polarization qubitsMar 01 2015Systematic errors are inevitable in most measurements performed in real life because of imperfect measurement devices. Reducing systematic errors is crucial to ensuring the accuracy and reliability of measurement results. To this end, delicate error-compensation ... More

Broadband frequency conversion via adiabatically tapered $χ^{(2)}$ waveguide in photonic integrated circuitsSep 29 2016We propose to use the integrated aluminum nitride waveguide with engineered width variation to achieve optical frequency conversion based on $\chi^{(2)}$ nonlinear effect on a photonic chip. We show that in an adiabatically tapered waveguide, the frequency ... More

Broadband opto-mechanical phase shifter for photonic integrated circuitsFeb 15 2012A broadband opto-mechanical phase shifter for photonic integrated circuits is proposed and numerically investigated. The structure consists of a mode-carrying waveguide and a deformable non-mode-carrying nanostring, which are parallel with each other. ... More

Remote Implementation of Quantum OperationsSep 08 2005Shared entanglement allows, under certain conditions, the remote implementation of quantum operations. We revise and extend recent theoretical results on the remote control of quantum systems as well as experimental results on the remote manipulation ... More

Coupling of light from an optical fiber taper into silver nanowiresJun 02 2009We report the coupling of photons from an optical fiber taper to surface plasmon modes of silver nanowires. The launch of propagating plasmons can be realized not only at ends of the nanowires, but also at the midsection. The degree of the coupling can ... More

Controlled Quantum Operations of a Semiconductor Three-Qubit SystemOct 21 2016The Coulomb interactions between electrons play important roles in coupling multiple qubits in various quantum systems. Here we demonstrate controlled quantum operations of three electron charge qubits based on three capacitively coupled semiconductor ... More

Coupling graphene nanomechanical motion to a single-electron transistorMar 24 2017Graphene-based electromechanical resonators have attracted much interest recently because of the outstanding mechanical and electrical properties of graphene and their various applications. However, the coupling between mechanical motion and charge transport ... More

Three-Leaf Dart-Shaped Single-Crystal BN Formation Promoted by Surface OxygenSep 30 2018Two-dimensional hexagonal boron nitride (h-BN) single crystals with various shapes have been synthesized by chemical vapor deposition over the past several years. Here we report the formation of three-leaf dart (3LD)-shaped single crystals of h-BN on ... More

Room-temperature steady-state optomechanics entanglement on a chipDec 30 2010A potential experimental system, based on the Silicon Nitride (SiN) material, is proposed to generate steady-state room-temperature optomechanical entanglement. In the proposed structure, the nanostring interacts dispersively and reactively with the microdisk ... More

Security of quantum key distribution with state-dependent imperfectionsSep 06 2010Dec 20 2011In practical quantum key distribution (QKD) system, the state preparation and measurement are imperfect comparing with the ideal BB84 protocol, which are always state-dependent in practical realizations. If the state-dependent imperfections can not be ... More

Security of practical phase-coding quantum key distributionNov 16 2009Security proof of practical quantum key distribution (QKD) has attracted a lot of attentions in recent years. Most of real-life QKD implementations are based on phase-coding BB84 protocol, which usually uses Unbalanced Mach-Zehnder Interferometer (UMZI) ... More

The effect of channel decoherence on entangled coherent states: A theoretical analysisMar 20 2013We analyse decoherence properties of entangled coherent states (ECSs) due to channel losses, and compare to the performance of bi-photon Bell states. By employing the concept of "entanglement of formation" (EOF), the degradation of fidelity and degree ... More

Computational Complexity of Continuous Variable Quantum Key DistributionFeb 01 2006Jun 03 2008The continuous variable quantum key distribution has been considered to have the potential to provide high secret key rate. However, in present experimental demonstrations, the secret key can be distilled only under very small loss rates. Here, by calculating ... More

Numerical Studies of Quantum Hall Ferromagnetism in Two-Subband SystemsJul 02 2008We carry out a numerical study of the quantum Hall ferromagnetism in a two-subband system using a set of experimental parameters in a recently experiment [X. C. Zhang, I. Martin, and H. W. Jiang, Phys. Rev. B \textbf{74}, 073301 (2006)]. Employing the ... More

Quantum simulation of Kibble-Zurek mechanism with a semiconductor electron charge qubitJan 23 2013The Kibble-Zurek mechanism provides a description of the topological structure occurring in the symmetry breaking phase transitions, which may manifest as the cosmological strings in the early universe or vortex lines in the superfulid. A particularly ... More

Interference of surface plasmon polaritions controlled by the phase of incident lightOct 09 2007Jun 04 2008Interference patterns of surface plasmon polaritons(SPPs) are observed in the extraordinary optical transmission through subwavelength holes in optically thick metal plate. It is found that the phase of incident light can be transferred to SPPs. We can ... More

Security of modified Ping-Pong protocol in noisy and lossy channelMay 13 2014The "Ping-Pong" (PP) protocol is a two-way quantum key protocol based on entanglement. In this protocol, Bob prepares one maximally entangled pair of qubits, and sends one qubit to Alice. Then, Alice performs some necessary operations on this qubit and ... More

Dynamic phase transitions of a driven Ising chain in a dissipative cavitySep 08 2016We study the nonequilibrium quantum phase transition of an Ising chain in a dissipative cavity driven by an external transverse light field. When driving and dissipation are in balance, the system can reach a nonequilibrium steady state which undergoes ... More

Physical accessible transformations on a finite number of quantum statesNov 09 2006We consider to treat the usual probabilistic cloning, state separation, unambiguous state discrimination, \emph{etc} in a uniform framework. All these transformations can be regarded as special examples of generalized completely positive trace non-increasing ... More

On-chip generation and control of the vortex beamSep 29 2015A new method to generate and control the amplitude and phase distributions of a optical vortex beam is proposed. By introducing a holographic grating on top of the dielectric waveguide, the free space vortex beam and the in-plane guiding wave can be converted ... More

Experimental Teleportation of a Quantum Controlled-NOT GateAug 02 2004Teleportation of quantum gates is a critical step for implementation of quantum networking and teleportation-based models of quantum computation. We report an experimental demonstration of teleportation of the prototypical quantum controlled-NOT (CNOT) ... More

Synthetic Landau levels and spinor vortex matter on Haldane spherical surface with magnetic monopoleDec 05 2017We present a flexible scheme to realize exact flat Landau levels on curved spherical geometry in a system of spinful cold atoms. This is achieved by Floquet engineering of a magnetic quadrupole field. We show that a synthetic monopole field in real space ... More

Is a rubidium cell with long decay time always useful for generating a non-classical photon pair?Dec 19 2008We experimentally find an interesting and unexpected thing: a rubidium cell with long decay time can not be used to generate a non-classical correlated photon pair via the D2 transition of $^{87}$Rb using four-wave mixing configuration [Opt. Express {\bf ... More

Gapped topological Fulde-Ferrell-Larkin-Ovchinnikov superfluids with artificial gauge potential and weak interactionDec 25 2017The topological superfluids with Majorana zero modes have not yet been realized in ultracold atoms with Rashba spin-orbit coupling. Here we show that these phases can be realized with an artificial gauge potential, which can be regarded as a site-dependent ... More

Anomalous isothermal compressibility in spin-orbit coupled degenerate Fermi gasesSep 08 2018The spin-orbit coupling (SOC) in degenerate Fermi gases can fundamentally change the fate of $s$-wave superfluids with strong Zeeman field and give rise to topological superfluids and associated Majorana zero modes. It also dramatically changes the thermodynamic ... More

Cavity-mediated oscillating and trapping dynamics in a two-component condensateJul 16 2018Cold atoms in cavity provides a new platform for exploring exotic many-body phases. Here we explore the dynamics of a two-component condensate coupled to a finesse cavity, in which the Raman coupling is mediated by pumping laser and cavity mode. In this ... More

Security proof of differential phase shift quantum key distribution in the noiseless caseJun 12 2008Oct 28 2008Differential phase shift quantum key distribution systems have a high potential for achieving high speed key generation. However, its unconditional security proof is still missing, even though it has been proposed for many years. Here, we prove its security ... More

Decoy State Quantum Key Distribution With Modified Coherent StateApr 29 2007To beat PNS attack, decoy state quantum key distribution (QKD) based on coherent state has been studied widely. We present a decoy state QKD protocol with modified coherent state (MCS). By destruction quantum interference, MCS with fewer multi-photon ... More

Extensible router for multi-user quantum key distribution networkAug 30 2006A feasible quantum key distribution (QKD) network scheme has been proposed with the wavelength routing. An apparatus called "quantum router", which is made up of many wavelength division multiplexers, can route the quantum signals without destroying their ... More

Intrinsic-Stabilization Uni-Directional Quantum Key Distribution Between Beijing and TianjinDec 03 2004Quantum key distribution provides unconditional security for communication. Unfortunately, current experiment schemes are not suitable for long-distance fiber transmission because of instability or backscattering. We present a uni-directional intrinsic-stabilization ... More

Realizing Quantum Controlled Phase Flip through Cavity-QEDAug 05 2004We propose a scheme to realize quantum controlled phase flip (CPF) between two rare earth ions embedded in respective microsphere cavity via interacting with a single-photon pulse in sequence. The numerical simulations illuminate that the CPF gate between ... More

Stability of Phase-modulated Quantum Key Distribution SystemAug 05 2004Phase drift and random fluctuation of interference visibility in double unbalanced M-Z QKD system are observed and distinguished. It has been found that the interference visibilities are influenced deeply by the disturbance of transmission fiber. Theory ... More

Quantum key distribution network with wavelength addressingOct 12 2006Oct 15 2006Most traditional applications of quantum cryptography are point-to-point communications, in which only two users can exchange keys. In this letter, we present a network scheme that enable quantum key distribution between multi-user with wavelength addressing. ... More

Characterizing high-quality high-dimensional quantum key distribution by state mapping between different degree of freedomsOct 04 2018Feb 15 2019Quantum key distribution (QKD) guarantees the secure communication between legitimate parties with quantum mechanics. High-dimensional QKD (HDQKD) not only increases the secret key rate but also tolerates higher quantum bit error rate (QBER). Many HDQKD ... More

Non-classical correlation of cascaded photon pairs emitted from quantum dotOct 16 2010Nov 14 2011We studied the quantum correlation between the photon pairs generated by biexciton cascade decays of self-assembled quantum dots, and determined the temperature behavior associated with so-called sudden change of the quantum correlation. The relationship ... More

Non-Markovian Entanglement Sudden Death and Rebirth of a Two-Qubit System in the Presence of System-Bath CoherenceOct 17 2010We present a detailed study of the entanglement dynamics of a two-qubit system coupled to independent non-Markovian environments, employing hierarchy equations. This recently developed theoretical treatment can conveniently solve non-Markovian problems ... More

Observation of the Preservation of the Two-Photon Coherence in Plasmon-assisted TransmissionDec 14 2005Feb 16 2006We experimentally study two-photon coherence in plasmon-assisted transmission with a two-photon Mach-Zehnder (MZ) interferometer. Two collinear photons of identical or orthogonal polarization are simultaneously incident on one optically thick metal film, ... More

Polarization properties of subwavelength hole arrays consisting of rectangular holesApr 06 2007Jun 04 2008Influence of hole shape on extraordinary optical transmission was investigated using hole arrays consisting of rectangular holes with different aspect ratio. It was found that the transmission could be tuned continuously by rotating the hole array. Further ... More