Results for "Guang-Can Guo"

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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
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
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
Ghost interference and diffraction based on the beam splitterJul 16 1997A simple scheme is proposed for observing the ghost interference and diffraction. The signal and the idler beams are produced by a beam splitter with the incident light being in a thermal state. A slit is inserted into the signal beam. We derive rigorously ... More
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
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
Teleporting a rotation on remote photonsMar 09 2005Apr 25 2005Quamtum remote rotation allows implement local quantum operation on remote systems with shared entanglement. Here we report an experimental demonstration of remote rotation on single photons using linear optical element. And the local dephase is also ... More
Local Operations in qubit arrays via global but periodic ManipulationOct 20 2006We provide a scheme for quantum computation in lattice systems via global but periodic manipulation, in which only effective periodic magnetic fields and global nearest neighbor interaction are required. All operations in our scheme are attainable in ... More
Compatibility Relations between the Reduced and Global Density MatrixesMar 22 2004It is a hard and important problem to find the criterion of the set of positive-definite matrixes which can be written as reduced density operators of a multi-partite quantum state. This problem is closely related to the study of many-body quantum entanglement ... 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
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
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
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
Probabilistic teleportation of two-particle entangled stateJun 01 2000In this letter, two different probabilistic teleportations of a two-particle entangled state by pure entangled three-particle state are shown. Their successful probabilities are different.
Origin of ferroelectricity in high-$T_c$ magnetic ferroelectric CuONov 15 2011May 04 2012Cupric oxide is a unique magnetic ferroelectric material with a transition temperature significantly higher than the boiling point of liquid nitrogen. However, the mechanism of high-T$_c$ multiferroicity in CuO remains puzzling. In this paper, we clarify ... More
A New Proof of The Strong Subadditivity TheoremJan 11 2004It is well known that the strong subadditivity theorem is hold for classical system, but it is very difficult to prove that it is hold for quantum system. The first proof of this theorem is due to Lieb by using the Lieb's theorem. Here we use the conditions ... More
Cooling of a levitated nanoparticle with digital parametric feedbackApr 09 2019The motion control of a levitated nanoparticle plays a central role in optical levitation for fundamental studies and practical applications. Here, we presented a digital parametric feedback cooling based on switching between two trapping laser intensity ... More
Unconventional Fulde-Ferrell-Larkin-Ovchinnikov pairing states in a Fermi gas with spin-orbit couplingJul 11 2013We study the phase diagram in a two-dimensional Fermi gas with the synthetic spin-orbit coupling that has recently been realized experimentally. In particular, we characterize in detail the properties and the stability region of the unconventional Fulde-Ferrell-Larkin-Ovchinnikov ... More
Synthetic topological Kondo insulator in a pumped optical cavityFeb 26 2018Motivated by experimental advances on ultracold atoms coupled to a pumped optical cavity, we propose a scheme for synthesizing and observing the Kondo insulator in Fermi gases trapped in optical lattices. The synthetic Kondo phase arises from the screening ... 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
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
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
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
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
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
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
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
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
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
Quantum Neural Network States: A Brief Review of Methods and ApplicationsAug 31 2018Feb 26 2019One of the main challenges of quantum many-body physics is that the dimensionality of the Hilbert space grows exponentially with the system size, which makes it extremely difficult to solve the Schr\"{o}dinger equations of the system. But typically, many ... 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
Tomography of the two-electron spin qubits in semiconductorsNov 09 2010Nov 18 2010We propose an approach to reconstruct two-electron spin qubit states in semiconductor quantum dots by employing tomographic techniques. This procedure exploits the combination of fast gate operations on electron spins trapped in dots and dynamical nuclear ... 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
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
Achieving quantum precision limit in adaptive qubit state tomographyMar 01 2015Feb 28 2016The precision limit in quantum state tomography is of great interest not only to practical applications but also to foundational studies. However, little is known about this subject in the multiparameter setting even theoretically due to the subtle information ... More
Efficient Quantum State Estimation with Over-complete TomographyAug 30 2011Jan 29 2012It is widely accepted that the selection of measurement bases can affect the efficiency of quantum state estimation methods, precision of estimating an unknown state can be improved significantly by simply introduce a set of symmetrical measurement bases. ... 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
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
Photon-assisted-tunneling in a coupled double quantum dot out of thermal equilibriumAug 17 2013We perform photon-assisted-tunneling (PAT) experiments on a GaAs double quantum dot device under high microwave excitation power. Photon-assisted absorption of up to 14 photons is observed, when electron temperature (>1K) are far above the lattice temperature. ... More
Efficient Machine Learning Representations of Surface Code with Boundaries, Defects, Domain Walls and TwistsFeb 11 2018Dec 13 2018Machine learning representations of many-body quantum states have recently been introduced as an ansatz to describe the ground states and unitary evolutions of many-body quantum systems. We explore one of the most important representations, restricted ... 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
Round-robin-differential-phase-shift quantum key distribution with and without monitoring signal disturbanceFeb 04 2017May 31 2017Round-robin-differential-phase (RRDPS) quantum key distribution (QKD) protocol has attracted intensive studies due to its distinct security characteristic, e.g., information leakage in RRDPS can be bounded without learning error rate of key bits. Nevertheless, ... More
Analogue to multiple electromagnetically induced transparency in all-optical drop-filter systemsJun 29 2007We theoretically study a parallel optical configuration which includes N periodically coupled whispering-gallery-mode resonators. The model shows an obvious effect which has a direct analogy with the phenomenon of multiple electromagnetically induced ... More
Nanocrystals in silicon photonic crystal standing-wave cavities as spin-photon phase gates for quantum information processingJun 01 2007Aug 13 2007By virtue of a silicon high-Q photonic crystal nanocavity, we propose and examine theoretically interactions between a stationary electron spin qubit of a semiconductor nanocrystal and a flying photon qubit. Firstly, we introduce, derive and demonstrate ... More
An Efficient Algorithmic Way to Construct Boltzmann Machine Representations for Arbitrary Stabilizer CodeSep 23 2018An efficient algorithm for constructing restricted Boltzmann machine (RBM) architecture of arbitrary stabilizer group is presented. Some partial results of this problem have been given in arXiv:1802.03738, in this work we give a complete solution via ... More
Hierarchy of Genuine Multipartite Quantum CorrelationsNov 13 2017Classifying states which exhibiting different statistical correlations is among the most important problems in quantum information science and quantum many-body physics. In bipartite case, there is a clear hierarchy of states with different correlations: ... More
Building quantum neural networks based on swap testApr 29 2019Artificial neural network, consisting of many neurons in different layers, is an important method to simulate humain brain. Usually, one neuron has two operations: one is linear, the other is nonlinear. The linear operation is inner product and the nonlinear ... More
Quantum key distribution based on quantum dimension and independent devicesFeb 10 2014Mar 07 2014In this paper, we propose a quantum key distribution (QKD) protocol based on only a two-dimensional Hilbert space encoding a quantum system and independent devices between the equipment for state preparation and measurement. Our protocol is inspired by ... More
Two-color ghost interference with photon pairs generated in hot atomsDec 11 2015We report on an experimental observation of a two-photon ghost interference experiment. A distinguishing feature of our experiment is that the photons are generated via a non-degenerated spontaneous four-wave mixing process in a hot atomic ensemble; therefore ... More
Bichromatic field generation from double-four-wave mixing in a double-electromagnetically induced transparency systemJul 17 2012Sep 10 2012We demonstrate the double electromagnetically induced transparency (double-EIT) and double four-wave mixing (double-FWM) based on a new scheme of non-degenerate four-wave mixing (FWM) involving five levels of a cold 85Rb atomic ensemble, in which the ... More
Realization of mutually unbiased bases for a qubit with only one wave plate: Theory and experimentMar 01 2015Feb 28 2016We consider the problem of implementing mutually unbiased bases (MUB) for a polarization qubit with only one wave plate, the minimum number of wave plates. We show that one wave plate is sufficient to realize two MUB as long as its phase shift (modulo ... More
Quantum statistical imaging of particles without restriction of the diffraction limitOct 09 2012Feb 21 2013A practical quantum measurement method based on the quantum nature of anti-bunching photon emission has been developed to detect single particles without the restriction of the diffraction limit. By simultane- ously counting the single-photon and two-photon ... More
Gradient optimization of finite projected entangled pair statesNov 29 2016May 04 2017The projected entangled pair states (PEPS) methods have been proved to be powerful tools to solve the strongly correlated quantum many-body problems in two-dimension. However, due to the high computational scaling with the virtual bond dimension $D$, ... More
Simulation of non-Abelian Anyons using ribbon operators connected to a common base siteDec 20 2012A convenient and effective way in the quantum double model to study anyons in a topological space with a tensor product structure is to create and braid anyons using ribbon operators connected to a common base site [A. Kitaev Ann.\ Phys. (N.Y.) \textbf{303}, ... More
Phase estimation with weak measurement using a white light sourceJun 20 2013We report results of a high precision phase estimation based on a weak measurements scheme using commercial light-emitting diode. The method is based on a measurement of the imaginary part of the weak value of a polarization operator. The imaginary part ... More
Highly-reduced Fine-structure splitting in InAs/InP quantum dots offering efficient on-demand 1.55 $μ$m entangled photon emitterJun 03 2008To generate entangled photon pairs via quantum dots (QDs), the exciton fine structure splitting (FSS) must be comparable to the exciton homogeneous line width. Yet in the (In,Ga)As/GaAs QD, the intrinsic FSS is about a few tens $\mu$eV. To achieve photon ... More
Solving frustrated quantum many-particle models with convolutional neural networksJul 25 2018Sep 26 2018Recently, there has been significant progress in solving quantum many-particle problem via machine learning based on the restricted Boltzmann machine. However, it is still highly challenging to solve frustrated models via machine learning, which has not ... More
Ultra-broadband continuously-tunable polarization entangled photon pair source covering the C+L telecom bands based on a single type-II PPKTP crystalNov 19 2012Jan 18 2013In this work, we report on the preparation of an ultra-broadband continuously-tunable, highly polarization-entangled photon-pair source covering the C+L telecom bands using a single type-II phase-matched bulk PPKTP crystal. Over 60 nm turning band of ... 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
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
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
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
Experimental nonlocal steering of Bohmian trajectoriesJun 19 2017Interpretations of quantum mechanics (QM), or proposals for underlying theories, that attempt to present a definite realist picture, such as Bohmian mechanics, require strong non-local effects. Naively, these effects would violate causality and contradict ... More
The Exclusivity Principle Determines the Correlation MonogamyJul 11 2017Adopting the graph-theoretic approach to the correlation experiments, we analyze the origin of monogamy and prove that it can be recognised as a consequence of exclusivity principle(EP). We provide an operational criterion for monogamy: if the fractional ... More
Parametric resonance of a Bose-Einstein condensate in a ring trap with periodically driven interactionsApr 28 2018We study the instability of a ring Bose-Einstein condensate under a periodic modulation of inter-atomic interactions. The condensate exhibits temporal and spatial patterns induced by the parametric resonance, which can be characterized by Bogoliubov quasi-particle ... More
Hidden correlations of exciton complexes in self-assembled quantum dots and ringsDec 08 2008The binding energies of trions ($X^+$, $X^-$) and biexciton (XX) in self-assembled semiconductor quantum dots (QDs) are very sensitive to the geometry and chemical composition of the QDs, and are random from dots to dots. However, in this letter, we show ... More
The in-plane gradient magnetic field induced vortex lattices in spin-orbit coupled Bose-Einstein condensationsNov 27 2014We consider the ground-state properties of the two-component spin-orbit coupled ultracold bosons subject to a rotationally symmetric in-plane gradient magnetic field. In the non-interacting case, the ground state supports giant-vortices carrying large ... More
Giant optical anisotropy in cylindrical self-assembled InAs/GaAs quantum ringsMay 14 2008Using a single-particle atomistic pseudopotential method followed by a many-particle configuration interaction method, we investigate the geometry, electronic structure and optical transitions of a self-assembled InAs/GaAs quantum ring (QR), changing ... More
Replica exchange molecular dynamics optimization of tensor network states for quantum many-body systemsApr 01 2014The tensor network states (TNS) methods combined with Monte Carlo (MC) techniques have been proved a powerful algorithm for simulating quantum many-body systems. However, because the ground state energy is a highly non-linear function of the tensors, ... More
Universal Optimal Gates Regarding Quantum Entanglement and Discord GeneratingJun 06 2013Jul 15 2013Fernando Galve \emph{et al.} $[Phys. Rev. Lett. \textbf{110}, 010501 (2013)]$ introduced discording power for a two-qubit unitary gate to evaluate its capability to produce quantum discord, and found that a $\pi/8$ gate has maximal discording power. This ... More
Gapless spin liquid ground state of spin-1/2 $J_1$-$J_2$ Heisenberg model on square latticesJun 19 2018The spin-1/2 $J_1$-$J_2$ Heisenberg model on square lattices are investigated via the finite projected entangled pair states (PEPS) method. Using the recently developed gradient optimization method combining with Monte Carlo sampling techniques, we are ... 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
Super-resolution quantum sensing using NV centers based on rotating linear polarized light and Monte-Carlo methodNov 29 2016The nitrogen vacancy (NV) center in diamond has been widely applied for quantum information and sensing in last decade. Based on the laser polarization dependent excitation of fluorescence emission, we propose a super-resolution microscopy of NV center. ... More
Frequency-up conversion and quantum swap gate in an optical cavity with atomic cloudJan 05 2008A scheme is presented for realizing frequency-up conversion and a two-qubit quantum swap gate for intracavity fields. In the scheme, a V-type atomic ensemble prepared in their ground states collectively mediates the interaction between the two cavity ... More
Phonon induced spin squeezing based on geometric phaseFeb 16 2015A scheme to achieve spin squeezing using a geometric phase induced by a single mechanical mode is proposed. The analytical and numerical results show that the ultimate degree of spin squeezing depends on the parameter $\frac{n_{th}+1/2}{Q\sqrt{N}}$, which ... More
Approach to accurately measuring the speed of optical precursorsFeb 24 2011Oct 04 2011Precursors can serve as a bound on the speed of information with dispersive medium. We propose a method to identify the speed of optical precursors using polarization-based interference in a solid-state device, which can bound the accuracy of the precursors' ... More
Interplay between non-Hermiticity and non-Abelian gauge potential in topological photonicsDec 06 2018Apr 22 2019Topological phases in spinless non-Hermitian models have been widely studied both theoretically and experimentally in some artificial materials using photonics, phononics and magnon. In this work, we investigate the interplay between non-Hermitian loss ... 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
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
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
Fulde-Ferrell superfluids in spinless ultracold Fermi gasesMay 09 2017Jun 06 2018The Fulde-Ferrell (FF) superfluid phase, in which fermions form finite-momentum Cooper pairings, is well studied in spin-singlet superfluids in past decades. Different from previous works that engineer the FF state in spinful cold atoms, we show that ... 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
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
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
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
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
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
Reviving the precision of multiple entangled probes in an open system by simple $π$-pulse sequencesOct 27 2016Quantum metrology with entangled states in realistic noisy environments always suffers from decoherence. Therefore, the measurement precision is greatly reduced. Here we applied the dynamical decoupling method to protect the $N$-qubit quantum metrology ... 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
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