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Results for "X. -X. Wu"

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Statistics of random lasing modes and amplified spontaneous emission spikes in weakly scattering systemsMar 28 2007We have measured the spectral correlations and intensity statistics of random lasing modes in weakly scattering systems, and compared them to those of the amplified spontaneous emission spikes. Their dramatic differences revealed the distinct physical ... More
Block model for the XY-type Landau-Ginzburg-Wilson Hamiltonian with an inhomogeneous temperatureJan 20 2012The phase fluctuation near the saddle point solution of the XY-type Landau-Ginzburg-Wilson Hamiltonian with random temperature is studied. For the modes with lowest eigenvalue, the systems is self-organized into blocks, which are coupled as a XY model ... More
Asymptotic Behavior of Error Exponents in the Wideband RegimeAug 31 2005In this paper, we complement Verd\'{u}'s work on spectral efficiency in the wideband regime by investigating the fundamental tradeoff between rate and bandwidth when a constraint is imposed on the error exponent. Specifically, we consider both AWGN and ... More
The fastest rotating pulsar: A strange star?Jan 01 2001Mar 28 2001According to the observational limits on the radius and mass, the fastest rotating pulsar (PSR 1937+21) is probably a strange star, or at least some neutron star equations of state should be ruled out, if we suggest that a dipole magnetic field is relevant ... More
Dissipation-based entanglement via quantum Zeno dynamics and Rydberg antiblockadeMay 10 2017A novel scheme is proposed for dissipative generation of maximally entanglement between two Rydberg atoms in the context of cavity QED. The spontaneous emission of atoms combined with quantum Zeno dynamics and Rydberg antiblockade guarantees a unique ... More
Predicting Unconventional High Temperature Superconductors in Trigonal Bipyramidal CoordinationsJun 12 2015Jun 19 2015Cuprates and iron-based superconductors are two classes of unconventional high Tc superconductors based on 3d transition elements. Recently, two principles, correspondence principle and magnetic selective pairing rule, have been emerged to unify their ... More
Dynamics of DistillabilityMay 30 2003The time evolution of a maximally entangled bipartite systems is presented in this paper. The distillability criterion is given in terms of Kraus operators. Using the criterion, we discuss the distillability of $2\times 2$ and $n\times n (n>2)$ systems ... More
The Dynamical Invariant of Open Quantum SystemOct 05 2015The dynamical invariant, whose expectation value is constant, is generalized to open quantum system. The evolution equation of dynamical invariant (the dynamical invariant condition) is presented for Markovian dynamics. Different with the dynamical invariant ... More
Dissipative stabilization of quantum-feedback-based multipartite entanglement with Rydberg atomsDec 31 2016A quantum-feedback-based scheme is proposed for generating multipartite entanglements of Rydberg atoms in a dissipative optical cavity. The Rydberg blockade mechanism efficiently prevents double excitations of the system, which is further exploited to ... More
The Dynamical Invariant of Open Quantum SystemOct 05 2015Oct 24 2017The dynamical invariant, whose expectation value is constant, is generalized to open quantum system. The evolution equation of dynamical invariant (the dynamical invariant condition) is presented for Markovian dynamics. Different with the dynamical invariant ... More
Pion Form Factor in the $k_T$ Factorization FormalismApr 20 2004Jun 12 2004Based on the light-cone (LC) framework and the $k_T$ factorization formalism, the transverse momentum effects and the different helicity components' contributions to the pion form factor $F_{\pi}(Q^2)$ are recalculated. In particular, the contribution ... More
Tunneling of Micro-sized Droplets Through a Flowing Soap FilmAug 14 2017Aug 30 2018When a micron-sized water droplet impacts on a freely suspended soap film with speed $v_{i}$, there exists a critical impact velocity of penetration $v_{C}$. For the droplet with $v_{i}<v_{C}$, it flows with the soap film after the impact whereas with ... More
Influence of bulk inversion asymmetry on the magneto-optical spectrum of a HgTe topological insulatorSep 22 2013The influence of bulk inversion asymmetry in [001] and [013] grown HgTe quantum wells is investigated theoretically. The bulk inversion asymmetry leads to an anti-crossing gap between two zero-mode Landau levels in a HgTe topological insulator, i.e., ... More
Quantum and Coulomb repulsion effects on the bubble structures in $^{204, 206}$HgSep 22 2018The decreasing proton and charge densities from around 5.0 fm towards the center of $^{204, 206}$Hg are investigated by a covariant density functional theory at the beyond mean-field level.The charge-density difference between $^{208}$Pb and $^{204}$Hg ... More
Direct solutions for normal depths in curved irrigation canalsSep 02 2013The normal depth is an important hydraulic element for canal design, operation and management. Curved irrigation canals including parabola, U-shaped and catenary canals have excellent hydraulic performance and strong ability of anti-frost heave, while ... More
Exact wave functions for the edge state of a disk-shaped two dimensional topological insulatorSep 22 2013We report the exact wave functions for the eigen state of a disk-shaped two dimensional topological insulator. The property of the edge state whose energy lies inside the bulk gap is studied. It is found that the edge state energy is affected by the radius ... More
A Unified Strouhal-Reynolds Number Relationship for Laminar Vortex Streets Generated by Different Shaped ObstaclesAug 14 2017A new Strouhal-Reynolds number relationship, $St=1/(A+B/Re)$, has been recently proposed based on observations of laminar vortex shedding from circular cylinders in a flowing soap film. Since the new $St$-$Re$ relation was derived from a general physical ... More
Landau level transitions in InAs/AlSb/GaSb quantum wellsMar 12 2015The electronic structure of InAs/AlSb/GaSb quantum wells embedded in AlSb barriers and in the presence of a perpendicular magnetic field is studied theoretically within the $14$-band ${\bf k}\cdot{\bf p}$ approach without making the axial approximation. ... More
Efficiency of electrical manipulation on two-dimensional topological insulatorsSep 21 2013We investigate the efficiency of electrical manipulation on two-dimensional topological insulators by considering a lateral potential superlattice on the system. The electronic states under various conditions are examined carefully. It is found that the ... More
Nuclear symmetry energy and hadron-quark mixed phase in neutron starsNov 15 2018We study the hadron-quark mixed phase, which may occur in the interior of neutron stars. The relativistic mean-field model is employed to describe the hadronic phase, while the Nambu--Jona-Lasinio model is used for the quark phase. We examine the effects ... More
Ultra High Energy Cosmic Rays: Strangelets? -- Extra dimensions, TeV-scale black holes and strange matterDec 04 2002Mar 15 2003The conjecture that ultra high energy cosmic rays (UHECRs) are actually strangelets is discussed. Besides the reason that strangelets can do as cosmic rays beyond the GZK-cutoff, another argument to support the conjecture is addressed in this letter via ... More
Engineering steady-state entanglement via dissipation and quantum Zeno dynamics in optical cavityMay 18 2017Mar 06 2018A new mechanism is proposed for dissipatively preparing maximal Bell entangled state of two atoms in an optical cavity. This scheme integrates the spontaneous emission, the light shift of atoms in the presence of dispersive microwave field, and the quantum ... More
Ground-state blockade of Rydberg atoms and application in entanglement generationMay 08 2017Dec 06 2017We propose a mechanism of ground-state blockade between two $N$-type Rydberg atoms in virtue of Rydberg-antiblockade effect and Raman transition. Inspired by the quantum Zeno effect, the strong Rydberg antiblockade interaction plays a role in frequently ... More
Asteroseismology of the $δ$ Scuti star HD 50844Jun 30 2016Aims. We aim to probe the internal structure and investigate more detailed information of the $\delta$ Scuti star HD 50844 with asteroseismology. Methods. We analyse the observed frequencies of the $\delta$ Scuti star HD 50844 obtained by Balona (2014), ... More
Experimentally realizable control fields in quantum Lyapunov controlFeb 24 2011As a hybrid of techniques from open-loop and feedback control, Lyapunov control has the advantage that it is free from the measurement-induced decoherence but it includes the system's instantaneous message in the control loop. Often, the Lyapunov control ... More
Effective Hamiltonian Approach to Open Systems and Its ApplicationsOct 16 2008By using the effective Hamiltonian approach, we present a self-consistent framework for the analysis of geometric phases and dynamically stable decoherence-free subspaces in open systems. Comparisons to the earlier works are made. This effective Hamiltonian ... More
GRB 060206: hints of precession of the central engine?Aug 08 2008Aims. The high-redshift (z = 4:048) gamma-ray burst GRB 060206 showed unusual behavior, with a significant rebrightening by a factor of ~ 4 at about 3000 s after the burst. We argue that this rebrightening implies that the central engine became active ... More
Adsorption, Segregation and Magnetization of a Single Mn Adatom on the GaAs (110) SurfaceMar 21 2005Density functional calculations with a large unit cell have been conducted to investigate adsorption, segregation and magnetization of Mn monomer on GaAs(110). The Mn adatom is rather mobile along the trench on GaAs(110), with an energy barrier of 0.56 ... More
Effects of uncertainties and errors on Lyapunov controlOct 11 2010Lyapunov control (open-loop) is often confronted with uncertainties and errors in practical applications. In this paper, we analyze the robustness of Lyapunov control against the uncertainties and errors in quantum control systems. The analysis is carried ... More
Time-dependent Decoherence-Free SubspaceMay 07 2012Sep 20 2012With time-dependent Lindblad operators, an open system may have a time-dependent decoherence-free subspace (t-DFS). In this paper, we define the t-DFS and present a necessary and sufficient condition for the t-DFS. Two examples are presented to illustrate ... More
Berry Phase and Hannay's Angle in a Quantum-Classical Hybrid SystemMar 19 2011Berry phase, which had been discovered for more than two decades, provides us a very deep insight on the geometric structure of quantum mechanics. Its classical counterpart--Hannay's angle is defined if closed curves of action variables return to the ... More
Canonical Form and Separability of PPT States in 2x2x2xN Composite Quantum SystemsOct 23 2003We give a canonical form of PPT states in ${\cal C}^2 \otimes {\cal C}^2\otimes {\cal C}^2 \otimes {\cal C}^N$ with rank=$N$. From this canonical form a necessary separable condition for these states is presented.
Testing quantum entanglement with local measurementOct 14 2011Apr 17 2012We propose to detect quantum entanglement by a condition of local measurments. We find that this condition can detect efficiently the pure entangled states for both discrete and continuous variable systems. It does not depend on interference of decoherence ... More
Skyrmions in Higher Landau LevelsFeb 27 1995We calculate the energies of quasiparticles with large numbers of reversed spins (``skyrmions'') for odd integer filling factors 2k+1, k is greater than or equals 1. We find, in contrast with the known result for filling factor equals 1 (k = 0), that ... More
Surface Junction in Bi$_2$Sr$_2$CaCu$_2$O$_{8+d}$ Single CrystalsMay 17 2003As nature junction geometry of the d-wave cuprate superconductor/insulator/the mixture of s-wave and d-wave cuprate superconductor, the upmost surface junction of intrinsic Josephson junction stack fabricated on Bi$_2$Sr$_2$CaCu$_2$O$_{8+d}$ single crystals ... More
Multiscale simulation on shearing transitions of thin-film lubrication with multi-layer moleculesMay 29 2017Shearing transitions of multi-layer molecularly thin-film lubrication systems in variations of the film-substrate coupling strength and the load are studied by using a multiscale method. Three kinds of the interlayer slips found in decreasing the coupling ... More
Quakes in Solid Quark StarsApr 28 2004May 27 2004A starquake mechanism for pulsar glitches is developed in the solid quark star model. It is found that the general glitch natures (i.e., the glitch amplitudes and the time intervals) could be reproduced if solid quark matter, with high baryon density ... More
Orientation of Galaxies in the Local Supercluster: A ReviewAug 31 2005The progress of the studies on the orientation of galaxies in the Local Supercluster (LSC) is reviewed and a summary of recent results is given. Following a brief introduction of the LSC, we describe the results of early studies based on two-dimensional ... More
Born-Oppenheimer approximation for open quantum systems within the quantum trajectory approachMar 05 2010Apr 17 2010Based on the quantum trajectory approach, we extend the Born-Oppenheimer (BO) approximation from closed quantum system to open quantum system, where the open quantum system is described by a master equation in Lindblad form. The BO approximation is defined ... More
Half-metallicity in aluminum-doped zigzag silicene nanoribbonsAug 29 2014The spin-dependent electronic structures of aluminum-(Al) doped zigzag silicene nanoribbons (ZSiNRs) are investigated by first-principles calculations. When ZSiNRs are substitutionally doped by a single Al atom on different sites in every three primitive ... More
Dissipative preparation of steady Greenberger-Horne-Zeilinger states for Rydberg atoms with quantum Zeno dynamicsSep 25 2017Dec 06 2017Inspired by a recent work [Reiter, Reeb, and S{\o}rensen, Phys. Rev. Lett. {\bf117}, 040501 (2016)], we present a simplified proposal for dissipatively preparing a Greenberger-Horne-Zeilinger (GHZ) state of three Rydberg atoms in a cavity. The $Z$ pumping ... More
Fractional Quantum Hall States in Low-Zeeman-Energy LimitDec 22 1993We investigate the spectrum of interacting electrons at arbitrary filling factors in the limit of vanishing Zeeman splitting. The composite fermion theory successfully explains the low-energy spectrum {\em provided the composite fermions are treated as ... More
Anisotropy of Cosmic AccelerationMay 13 2013May 16 2013In this paper, we study the anisotropy of cosmic acceleration by dividing the Union2 Type Ia supernova dataset into 12 subsets according to their positions in Galactic coordinate system. In each region, we derive the deceleration parameter $q_0$ as the ... More
Quadrupole collectivity and shell closure in neutron-rich nuclei around $N=126$Feb 19 2019May 14 2019We present a comprehensive study on the low-lying states of neutron-rich Er, Yb, Hf, and W isotopes across the $N=126$ shell with a multi-reference covariant density functional theory. Beyond mean-field effects from shape mixing and symmetry restoration ... More
The Nature of the Diffuse Clumps and the X-ray Companion of Mrk 273May 17 1999We present an optical spectrum for Mrk 273x, the X-ray source 1.3' to the northeast of Mrk 273. The new spectrum indicates that the object is at a much higher redshift (0.458) than the value (0.0376) previously reported. All the detected emission lines ... More
Excitation Spectrum of Composite FermionsMar 15 1994We show that the excitation spectrum of interacting electrons at filling factor $\nu=\nu^*/(2\nu^*+1)$ is well described in terms of non-interacting composite fermions at filling factor $\nu^*$, but does not have a one-to-one correspondence with the excitation ... More
Photonic band structure of ZnO photonic crystal slab laserMar 21 2005We recently reported on the first realization of ultraviolet photonic crystal laser based on zinc oxide [Appl. Phys. Lett. {\bf 85}, 3657 (2004)]. Here we present the details of structural design and its optimization. We develop a computational super-cell ... More
Multilevel quantum Otto heat engines with identical particlesFeb 23 2018A quantum Otto heat engine is studied with multilevel identical particles trapped in one-dimensional box potential as working substance. The symmetrical wave function for Bosons and the anti-symmetrical wave function for Fermions are considered. In two-particle ... More
Effect of iron-doping on spin-state transition and ferromagnetism in Pr$_{0.5}$Ca$_{0.5}$CoO$_{3-δ}$ cobalt oxidesSep 21 2005Resistivity and dc magnetization measurements were performed for the polycrystalline Pr$_{0.5}$Ca$_{0.5}$Co$_{1-x}$Fe$_{x}$O$_{3-\delta}$ ($x$ = 0, 0.05, 0.10 and 0.15) samples. The as-fabricated samples exhibit ferromagnetic (FM) transition and the transition ... More
Adiabatic Decoherence-Free Subspaces and its ShortcutsMay 04 2017Oct 24 2017The adiabatic theorem and "shortcuts to adiabaticity" for the adiabatic dynamics of time-dependent decoherence-free subspaces are explored in this paper. Starting from the definition of the dynamical stable decoherence-free subspaces, we show that, under ... More
Information Flow, Non-Markovianity and Geometric PhasesNov 18 2010Geometric phases and information flows of a two-level system coupled to its environment are calculated and analyzed. The information flow is defined as a cumulant of changes in trace distance between two quantum states, which is similar to the measure ... More
Separability and entanglement in 2x3xN composite quantum systemsAug 28 2003The separability and entanglement of quantum mixed states in $\Cb^2 \otimes \Cb^3 \otimes \Cb^N$ composite quantum systems are investigated. It is shown that all quantum states $\rho$ with positive partial transposes and rank $r(\rho)\leq N$ are separable. ... More
Dynamics of quantum-classical hybrid system: effect of matter-wave pressureOct 21 2009Radiation pressure affects the kinetics of a system exposed to the radiation and it constitutes the basis of laser cooling. In this paper, we study {\it matter-wave pressure} through examining the dynamics of a quantum-classical hybrid system. The quantum ... More
Driving Quantum System into Decoherence-free Subspaces by Lyapunov ControlAug 07 2009We present a scheme to drive a finite-dimensional quantum system into the decoherence-free subspaces(DFS) by Lyapunov control. Control fields are established by Lyapunov function. This proposal works well for both closed and open quantum systems, with ... More
The D0$-$D8 system revisitedSep 06 2009Oct 25 2009We address a few subtle issues regarding the interacting D0-D8 system. There are two existing interpretations for the counter-intuitive non-vanishing cylinder-diagram R-R potential. We improve them each by properly dealing with the divergence of potential ... More
Quadrupole collectivity and shell closure in neutron-rich nuclei around $N=126$Feb 19 2019We present a comprehensive study on the low-lying states of neutron-rich Er, Yb, Hf, and W isotopes across the $N=126$ shell with a multi-reference covariant density functional theory. Beyond mean-field effects from shape mixing and symmetry restoration ... More
Exact results for polaron and molecule in one-dimensional spin-1/2 Fermi gasNov 03 2016Using exact Bethe ansatz (BA) solutions, we show that a spin-down fermion immersed into a fully polarized spin-up Fermi sea with a weak attraction is dressed by the surrounding spin-up fermions to form the one-dimensional analog of a polaron. As the attraction ... More
GRB 030226 in a Density-Jump MediumMay 22 2003We present an explanation for the unusual temporal feature of the GRB 030226 afterglow. The R-band afterglow of this burst faded as ~ t^{-1.2} in ~ 0.2 days after the burst, rebrightened during the period of ~ 0.2 - 0.5 days, and then declined with ~ ... More
The braking indices in pulsar emission modelsJul 20 2003Aug 23 2003Using the method proposed in a previous paper, we calculate pulsar braking indices in the models with torque contributions from both inner and outer accelerating regions, assuming that the interaction between them is negligible. We suggest that it is ... More
Excitation Spectrum and Collective Modes of Composite FermionsSep 13 1994According to the composite fermion theory, the interacting electron system at filling factor $\nu$ is equivalent to the non-interacting composite fermion system at $\nu^*=\nu/(1-2m\nu)$, which in turn is related to the non-interacting electron system ... More
Hund's Rule for Composite FermionsDec 22 1993We consider the ``fractional quantum Hall atom" in the vanishing Zeeman energy limit, and investigate the validity of Hund's maximum-spin rule for interacting electrons in various Landau levels. While it is not valid for {\em electrons} in the lowest ... More
Electron spin relaxation in GaAs$_{1-x}$Bi$_x$: Effects of spin-orbit tuning by Bi incorporationMay 27 2012The electron spin relaxation in $n$-type and intrinsic GaAs$_{1-x}$Bi$_x$ with Bi composition $0\le x \le 0.1$ is investigated from the microscopic kinetic spin Bloch equation approach. The incorporation of Bi is shown to markedly decrease the spin relaxation ... More
Transport properties in Cu$_{x}$TiSe$_{2}$ (0.015$\leq$x$\leq$0.110) Single CrystalMar 25 2007Transport properties are systematically studied for the single crystals Cu$_{x}$TiSe$_{2}$ (0.015$\leq$x$\leq$0.110). Both of in-plane and out-of-plane resistivity show the coexistence of superconducting transition and charge density wave (CDW) for the ... More
Novel dynamical effects and glassy response in strongly correlated electronic systemMar 25 2007We find an unconventional nucleation of low temperature paramagnetic metal (PMM) phase with monoclinic structure from the matrix of high-temperature antiferromagnetic insulator (AFI) phase with tetragonal structure in strongly correlated electronic system ... More
Giant isotope effect and spin state transition induced by oxygen isotope exchange in ($Pr_{1-x}Sm_x)_{0.7}Ca_{0.3}CoO_3$Mar 28 2006Apr 30 2006We systematically investigate effect of oxygen isotope in $(Pr_{1-x}Sm_x)_{0.7}Ca_{0.3}CoO_3$ which shows a crossover with x from ferromagnetic metal to the insulator with spin-state transition. A striking feature is that effect of oxygen isotope on the ... More
Electron tunneling through a single magnetic barrier in HgTe topological insulatorJul 20 2016Electron tunneling through a single magnetic barrier in a HgTe topological insulator has been theoretically investigated. We find that the perpendicular magnetic field would not lead to spin-flip of the edge states due to the conservation of the angular ... More
Charge ordering in charge-compensated $Na_{0.41}CoO_2$ by oxonium ionsJan 10 2005Dec 20 2005Charge ordering behavior is observed in the crystal prepared through the immersion of the $Na_{0.41}CoO_2$ crystal in distilled water. Discovery of the charge ordering in the crystal with Na content less than 0.5 indicates that the immersion in water ... More
Quantum correlation measure in arbitrary bipartite systemsSep 04 2013Oct 09 2013A definition of quantum correlation is presented for an arbitrary bipartite quantum state based on the skew information. This definition not only inherits the good properties of skew information such as the contractivity and so on, but also is effective ... More
X-Ray Afterglow Plateaus of Long Gamma-Ray Bursts: Further Evidence for Millisecond MagnetarsJan 08 2014Many long-duration gamma-ray bursts (GRBs) were observed by {\it Swift}/XRT to have plateaus in their X-ray afterglow light curves. This plateau phase has been argued to be evidence for long-lasting activity of magnetar (ultra-strongly magnetized neutron ... More
Unusual glitch behaviours of two young pulsarsJul 22 2004In this paper we report unusual glitches in two young pulsars, PSR J1825-0935 (B1822-09) and PSR J1835-1106. For PSR J1825-0935, a slow glitch characterised by a temporary decrease in the slowdown rate occurred between 2000 December 31 to 2001 December ... More
Sorption of Eu(III) on Attapulgite Studied by Batch, XPS and EXAFS TechniquesDec 04 2009The effects of pH, ionic strength and temperature on sorption of Eu(III) on attapulgite were investigated in the presence and absence of fulvic acid (FA) and humic acid (HA). The results indicated that the sorption of Eu(III) on attapulgite was strongly ... More
Metastable giant moments in Gd-implanted GaN, Si, and sapphireMar 28 2011We report on Gd ion implantation and magnetic characterization of GaN films on sapphire substrates and of bare sapphire and Si substrates to shed light on the mechanism underlying the induced magnetism upon Gd ion implantation. For all three hosts, giant ... More
Quantum logic gates and maximally entangled states in microtrapsApr 05 2002Apr 08 2002This paper has been withdrawn because the first author submitted the paper without previously consulting the rest of the authors.
Strain tuning of optical emission energy and polarization in monolayer and bilayer MoS2Jun 14 2013We use micro-Raman and photoluminescence (PL) spectroscopy at 300K to investigate the influence of uniaxial tensile strain on the vibrational and optoelectronic properties of monolayer and bilayer MoS2 on a flexible substrate. The initially degenerate ... More
Two superconducting phases and their characteristics in layered BaTi2(Sb1-xBix)2O with x=0.16May 09 2014Two correlated superconducting phases are identified in layered superconductor BaTi2(Sb1-xBix)2O (x=0.16), with the superconducting transition temperatures of TC = 6 K (the high TC phase) and 3.4 K (the low TC Phase), respectively. The 6 K superconducting ... More
Low-temperature heat transport of CuFe$_{1-x}$Ga$_x$O$_2$ ($x =$ 0--0.12) single crystalsMay 30 2017We report a study on the thermal conductivity of CuFe$_{1-x}$Ga$_x$O$_2$ ($x =$ 0--0.12) single crystals at temperatures down to 0.3 K and in magnetic fields up to 14 T. CuFeO$_2$ is a well-known geometrically frustrated triangular lattice antiferromagnet ... More
Heat switch effect in an antiferromagnetic insulator Co$_3$V$_2$O$_8$Jun 07 2016We report a heat switch effect in single crystals of an antiferromagnet Co$_3$V$_2$O$_8$, that is, the thermal conductivity ($\kappa$) can be changed with magnetic field in an extremely large scale. Due to successive magnetic phase transitions at 12--6 ... More
Entanglement of Fermi gases in a harmonic trapOct 27 2005For both cases with and without interactions, bipartite entanglement of two-fermions from a Fermi gas in a trap is investigated. We show how the entanglement depends on the locations of the two fermions and the total number of particles. Fermions at the ... More
Self-optimization of optical confinement in ultraviolet photonic crystal slab laserDec 08 2005We studied numerically and experimentally the effects of structural disorder on the performance of ultraviolet photonic crystal slab lasers. Optical gain selectively amplifies the high-quality modes of the passive system. For these modes, the in-plane ... More
Gap solitons and Bloch waves of interacting bosons in one-dimensional optical lattices: From the weak to the strong interaction limitsMar 06 2011We study the gap solitons and nonlinear Bloch waves of interacting bosons in one-dimensional optical lattices, taking into account the interaction from the weak to the strong limits. It is shown that composition relation between the gap solitons and nonlinear ... More
Infrared spectroscopy of the charge ordering transition in Na$_{0.5}$CoO$_2$May 11 2004We report infrared spectra of a Na$_{0.5}$CoO$_2$ single crystal which exhibits a sharp metal-insulator transition near 50 K due to the formation of charge ordering. In comparison with x=0.7 and 0.85 compounds, we found that the spectral weight associated ... More
Influence of doping level on the Hall coefficient and on the thermoelectric power in $Nd_{2-x}Ce_xCuO_4$Jun 25 2005Oct 20 2005Hall coefficient $R_H$ and thermoelectric power TEP are studied systematically in the single crystals $Nd_{2-x}Ce_xCuO_{4+\delta}$ (NCCO) with different x from underdoped to overdoped regime. With increasing doping level, both $R_H$ and TEP decrease and ... More
Excitons in two coupled conjugated polymer chainsSep 23 1997We have studied the exciton states in two coupled conjugated polymer chains which are modeled individually by the Su-Schrieffer-Heeger Hamiltonian and coupled by an interchain electron-transfer term. Both the intra- and inter-chain long range Coulomb ... More
Coupling Matrix Representation of Nonreciprocal Filters Based on Time Modulated ResonatorsMay 20 2019This paper addresses the analysis and design of non-reciprocal filters based on time modulated resonators. We analytically show that time modulating a resonator leads to a set of harmonic resonators composed of the unmodulated lumped elements plus a frequency ... More
Skyrmions in the Fractional Quantum Hall EffectApr 03 1996It is verified that, at small Zeeman energies, the charged excitations in the vicinity of 1/3 filled Landau level are skyrmions of composite fermions, analogous to the skyrmions of electrons near filling factor unity. These are found to be relevant, however, ... More
Fermi-liquid effects in the gapless state of marginally thin superconducting filmsSep 24 2008We present low temperature tunneling density-of-states measurements in Al films in high parallel magnetic fields. The thickness range of the films, t=6-9 nm, was chosen so that the orbital and Zeeman contributions to their parallel critical fields were ... More
Absorption-induced confinement of lasing modes in diffusive random mediumApr 18 2005We present a numerical study of lasing modes in diffusive random media with local pumping. The reabsorption of emitted light suppresses the feedback from the unpumped part of the sample and effectively reduces the system size. The lasing modes are dramatically ... More
Exact dynamics of interacting qubits in a thermal environment: Results beyond the weak coupling limitJul 30 2012We demonstrate an exact mapping of a class of models of two interacting qubits in thermal reservoirs to two separate spin-bath problems. Based on this mapping, exact numerical simulations of the qubits dynamics can be performed, beyond the weak system-bath ... More
Nonlinear quantum heat transfer in hybrid structures: Sufficient conditions for thermal rectificationMay 25 2009We present a unified description of heat flow in two-terminal hybrid quantum systems. Using simple models, we analytically study nonlinear aspects of heat transfer between various reservoirs: metals, solids, and spin baths, mediated by the excitation/relaxation ... More
The Galilean Nature of V-duality for Noncommutative Open String and Yang-Mills TheoriesDec 26 2000Feb 09 2001A V-duality conjecture for noncommutative open string theories (NCOS) that result from decoupling D-branes in Lorentz-boost related backgrounds was put forward recently in hep-th/0006013. The aim of this paper is to test the Galilean nature of this conjecture ... More
Phase Structure of Kerr-AdS Black HoleApr 04 2011Dec 09 2011We study the critical phenomena of Kerr-AdS black hole. Phase structures are observed at different temperatures, $T_{L}$, $T_{c1}$ and $T_{c2}$ with various features. We discuss the thermal stability considering the isothermal compressibility and how ... More
Testing the Predictions of the Universal-Structured Jet Model of Gamma-Ray Bursts by SimulationsJul 21 2004Based on the standard energy reservoir of gamma-ray burst (GRB) jets and the relationship between peak energy ($E_p$) of $\nu F_{\nu}$ spectrum and the equivalent-isotropic energy ($E_{\rm{iso}}$), we test the GRB probability distributions as a function ... More
Dynamics of ultra-intense circularly polarized solitons under inhomogeneous plasmasMar 18 2013The dynamics of the ultra-intense circularly polarized solitons under inhomogeneous plasmas are examined. The interaction is modeled by the Maxwell and relativistic hydrodynamic equations and is solved with fully implicit energy-conserving numerical scheme. ... More
The breather like penetration of the ultra-short linearly polarized laser into over-dense plasmasDec 03 2012Jan 10 2013Relativistic electromagnetic penetration behavior is reexamined in the relativistic transparency region. The interaction is modeled by the relativistic hydrodynamic equations coupled with the full system of Maxwell equations, which are solved by a fully ... More
Spin-polarized transport in a lateral two-dimensional diluted magnetic semiconductor electron gasSep 23 2005The transport property of a lateral two-dimensional diluted magnetic semiconductor electron gas under a spatially periodic magnetic field is investigated theoretically. We find that the electron Fermi velocity along the modulation direction is highly ... More
Anomalies in non-stoichiometric uranium dioxide induced by pseudo-phase transition of point defectsApr 20 2012A uniform distribution of point defects in an otherwise perfect crystallographic structure usually describes a unique pseudo phase of that state of a non-stoichiometric material. With off-stoichiometric uranium dioxide as a prototype, we show that analogous ... More
Theoretical assessment on the possibility of constraining point defect energetics by pseudo-phase transition pressuresMay 29 2013Making use of the energetics and equations of state of defective uranium dioxide that calculated with first-principles method, we demonstrate a possibility of constraining the formation energy of point defects by measuring the transition pressures of ... More
Could FRB 131104 Originate from the Merger of Binary Neutron Stars?Nov 29 2016Dec 04 2016Recently, DeLaunay et al. (2016) discovered a gamma-ray transient, Swift J0644.5-5111, associated with the fast radio burst (FRB) 131104. They also reported follow-up broadband observations beginning two days after the FRB and provided upper limits on ... More
Thermometry of Guided Molecular Beams from a Cryogenic Buffer-Gas CellMay 27 2016We present a comprehensive characterization of cold molecular beams from a cryogenic buffer-gas cell, providing an insight into the physics of buffer-gas cooling. Cold molecular beams are extracted from a cryogenic cell by electrostatic guiding, which ... More
Composition and reactivity on Pd/Au(111) surface: A first-principle studyJan 31 2007Atomic configurations of two or three Pd substituents on the Au(111) surface are investigated using the first-principles pseudopotential plane wave approach. Pd atoms are found to form second neighborhoods on PdAu(111). The Pd-d band becomes narrow and ... More