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Results for "R. -Z. Liu"

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Correlation and Relaxation Times for a Stochastic Process with a Fat-Tailed Steady-State DistributionAug 03 2016We study a stochastic process defined by the interaction strength for the return to the mean and a stochastic term proportional to the magnitude of the variable. Its steady-state distribution is the Inverse Gamma distribution, whose power-law tail exponent ... More
New emission phase of the Be/X-ray binary X Persei: nearly simultaneous spectroscopic and near-infrared observationsJan 03 2001We present a series of optical spectroscopic and near-infrared photometric observations of the Be star X Persei, from the beginning of the recent emission phase. Our data show that after the latest extended low state (ELS), both the equivalent width (EW) ... More
Prospects for Testing Lorentz and CPT Invariance in the Top-Quark SectorJul 22 2016We present how to further the search for Lorentz and CPT violation in the top-quark sector after the first measurement in this sector by D0. We compute the Lorentz-violating matrix element for top pair production via gluon fusion, which allows a similar ... More
Swapping entangled Kondo resonances in parallel-coupled double quantum dotsMar 25 2004Strong electron and spin correlations are studied in parallel-coupled double quantum dots with interdot spin superexchange $J$. In the Kondo regime with {\it}{degenerate} dot energy levels, a coherent transport occurs at zero temperature, where two entangled ... More
Rare $B$ decays using lattice QCD form factorsJan 02 2015Mar 20 2015In this write-up we review and update our recent lattice QCD calculation of $B \to K^*$, $B_s \to \phi$, and $B_s \to K^*$ form factors [arXiv:1310.3722]. These unquenched calculations, performed in the low-recoil kinematic regime, provide a significant ... More
Selection Rule in Josephson Coupling between In and Sr2RuO4Sep 14 1999We have studied the Josephson coupling between a conventional s-wave superconductor (In) and Sr2RuO4 and found that the coupling is allowed in the in-plane direction, but not along the c axis. This selection rule indicates that the symmetry of superconducting ... More
Hierarchy of fractional Chern insulators and competing compressible statesJul 25 2012We study the phase diagram of interacting electrons in a dispersionless Chern band as a function of their filling. We find hierarchy multiplets of incompressible states at fillings \nu=1/3, 2/5, 3/7, 4/9, 5/9, 4/7, 3/5 as well as \nu=1/5,2/7. These are ... More
Breakdown of the coexistence of spin-singlet superconductivity and itinerant ferromagnetismJun 22 2002We discuss the possibility of coexistence of spin-singlet superconductivity and ferromagnetism in a model where the same electrons are assumed responsible for both of them. Our calculations include both zero and finite momentum pairing states with both ... More
On the nulling, drifting, and their interactions in PSRs J1741-0840 and J1840-0840Oct 26 2017We report detailed investigation of nulling and drifting behavior of two pulsars PSRs J1741-0840 and J1840-0840 observed from the Giant Meterwave Radio Telescope at 625 MHz. PSR J1741-840 was found to show nulling fraction (NF) of around 30(5)% while ... More
The Landau-Lifshitz-Bloch equation for domain wall motion in antiferromagnetsDec 03 2018Feb 06 2019In this work, we derive the Landau-Lifshitz-Bloch equation accounting for the multi-domain antiferromagnetic (AFM) lattice at finite temperature, in order to investigate the domain wall (DW) motion, the core issue for AFM spintronics. The continuity equation ... More
A very large glitch in PSR B2334+61Jul 07 2010Seven years of pulse time-of-arrival measurements have been collected from observations of the young pulsar PSR B2334+61 using the Nanshan radio telescope of Urumqi Observatory. A phase-connected solution has been obtained over the whole data span, 2002 ... More
Pentaquark Magnetic Moments In Different ModelsDec 04 2003Feb 27 2004We calculate the magnetic moments of the pentaquark states from different models and compare our results with predictions of other groups.
The Cohomology of Transitive Lie AlgebroidsDec 27 2007For a transitive Lie algebroid A on a connected manifold M and its a representation on a vector bundle F, we study the localization map Y^1: H^1(A,F)-> H^1(L_x,F_x), where L_x is the adjoint algebra at x in M. The main result in this paper is that: Ker ... More
Heavy PentaquarksJan 24 2004Apr 02 2004We construct the spin-flavor wave functions of the possible heavy pentaquarks containing an anti-charm or anti-bottom quark using various clustered quark models. Then we estimate the masses and magnetic moments of the $J^P={1\over 2}^+$ or ${3\over 2}^+$ ... More
On (Co-)morphisms of Lie Pseudoalgebras and GroupoidsOct 11 2007We give a unified description of morphisms and comorphisms of Lie pseudoalgebras, showing that the both types of morphisms can be regarded as subalgebras of a Lie pseudoalgebra, called the $\psi$-sum. We also provide similar descriptions for morphisms ... More
Optimized contraction scheme for tensor-network statesMay 24 2017Jul 21 2017In the tensor-network framework, the expectation values of two-dimensional quantum states are evaluated by contracting a double-layer tensor network constructed from initial and final tensor-network states. The computational cost of carrying out this ... More
Omni-Lie algebroidsOct 10 2007A generalized Courant algebroid structure is defined on the direct sum bundle D(E) +J(E), where D(E) and J(E) are the gauge Lie algebroid and the jet bundle of a vector bundle E respectively. Such a structure is called an omni-Lie algebroid since it is ... More
Electrical Transport Properties of Single Crystal Sr3Ru2O7: The Possible Existence of an Antiferromagnetic Instability at Low TemperaturesFeb 08 2001We report the results of Hall coefficient R_H and magnetoresistance (MR) measurements on single crystalline samples of Sr3Ru2O7 grown by the floating zone method. R_H was found to be positive over the entire temperature range studied (0.3 - 300K). Its ... More
Tuning of electronic and optic anisotropy in GaAs quantum ringsAug 25 2016This work presents theoretical study on electronic and anisotropy in a quantum ring formed on AlGaAs/GaAs heterostructures. We demonstrate the effective modulation of the electron distribution and optical absorption in quantum rings utilizing the interplay ... More
Improved time-resolved magneto-optical Kerr effect technique and dynamic magnetization reversal mechanism of perpendicularly magnetized $L1_{\mathrm{0}}$ FePt filmsDec 07 2008Jan 31 2009The dynamic coercivity cannot be measured rigorously by the conventional time-resolved magneto-optical Kerr effect technique because the irreversible deviation of the transient magnetization is accumulated. In order to remove the accumulation effect, ... More
Three-dimensional simulations of the interaction between Type Ia supernova ejecta and their main sequence companionsSep 20 2012The identity of the progenitor systems of SNe Ia is still uncertain. In the single-degenerate (SD) scenario, the interaction between the SN blast wave and the outer layers of a main sequence (MS) companion star strips off H-rich material which is then ... More
The color gradients of spiral disks in the Sloan Digital Sky SurveyMay 25 2009We investigate the radial color gradients of galactic disks using a sample of about 20,000 face-on spiral galaxies selected from the fourth data release of the Sloan Digital Sky Survey (SDSS-DR4). We combine galaxies with similar concentration, size and ... More
Novel Two-dimensional SiC2 Sheet with Full Pentagon NetworkJul 24 2013We propose a promising two-dimensional nano-sheet of SiC2 (SiC2-pentagon) consisting of tetrahedral silicon atoms and triple-linked carbon atoms in a fully-pentagon network. The SiC2-pentagon with buckled configuration is more favorable than its planar ... More
Topological Insulators in Hexagonal Wurtzite-type Binary CompoundsMar 28 2013We propose new topological insulators in hexagonal wurtzite-type binary compounds based on the first principles calculations. It is found that two compounds AgI and AuI are three-dimensional topological insulators with a naturally opened band-gap at Fermi ... More
Role of further-neighbor interactions in modulating the critical behavior of the Ising model with frustrationFeb 24 2016In this work, we investigate the phase transitions and critical behaviors of the frustrated J1-J2-J3 Ising model on the square lattice using Monte Carlo simulations, and particular attention goes to the effect of the second next nearest neighbor interaction ... More
$J^P={1/2}^-$ Pentaquarks in Jaffe and Wilczek's Diquark ModelMar 19 2004Mar 23 2004If Jaffe and Wilczek's diquark picture for $\Theta_5$ pentaquark is correct, there should also exist a $SU_F$(3) pentaquark octet and singlet with no orbital excitation between the diquark pair, hence $J^P={1/2}^-$. These states are lighter than the $\Theta_5$ ... More
Magnetic Moments of $J^P={3/2}^+$ PentaquarksDec 29 2003Jan 16 2004If the $J^P$ of $\Theta_5^+$ and $\Xi_5^{--}$ pentaquarks is really found to be ${1\over 2}^+$ by future experiments, they will be accompanied by $J^P={3\over 2}^+$ partners in some models. It is reasonable to expect that these $J^P={3\over 2}^+$ states ... More
Heavy and Light Pentaquark Chiral LagrangianApr 15 2004Using the SU(3) flavor symmetry, we construct the chiral Lagrangians for the light and heavy pentaquarks. The correction from the nonzero quark is taken into account perturbatively. We derive the Gell-Mann$-$Okubo type relations for various pentaquark ... More
Observations of Six Glitches in PSR B1737-30Nov 08 2007Nov 14 2007Six glitches have been recently observed in the rotational frequency of the young pulsar PSR B1737-30 (J1740-3015) using the 25-m Nanshan telescope of Urumqi Observatory. With a total of 20 glitches in 20 years, it is one of the most frequently glitching ... More
Broadband terahertz generation via the interface inverse Rashba-Edelstein effectApr 13 2018Novel mechanisms for electromagnetic wave emission in the terahertz (THz) frequency regime emerging at the nanometer scale have recently attracted intense attention for the purpose of searching next-generation broadband THz emitters. Here, we report a ... More
Performance Analysis of Location Profile RoutingMar 19 2014We propose using the predictability of human motion to eliminate the overhead of distributed location services in human-carried MANETs, dubbing the technique location profile routing. This method outperforms the Geographic Hashing Location Service when ... More
The non-constant slope of the CIV Baldwin effect in NGC 4151May 05 2006May 29 2006The relationship between the emission-line equivalent width and the continuum luminosity, so called the Baldwin effect, plays an important role in studying the physics of the broad line region of AGNs. Using the archived ultraviolet spectra obtained by ... More
29 Glitches Detected at Urumqi ObservatoryJan 10 2010Glitches detected in pulsar timing observations at the Nanshan radio telescope of Urumqi Observatory between 2002 July and 2008 December are presented. In total, 29 glitches were detected in 19 young pulsars, with this being the first detection of a glitch ... More
Controllable scattering of photons inside a one-dimensional resonator waveguideFeb 28 2008Sep 24 2008We analyze coherent transport of photons, which propagate in a one-dimensional coupled-resonator waveguide (CRW) and are scattered by a controllable two-level system located inside the CRW. Our approach, which uses discrete coordinates, unifies "low" ... More
Spin Dynamics in the Second Subband of a Quasi Two Dimensional System Studied in a Single Barrier Heterostructure by Time Resolved Kerr RotationMar 25 2008By biasing a single barrier heterostructure with a 500nm-thick GaAs layer as the absorption layer, the spin dynamics for both of the first and second subband near the AlAs barrier are examined. We find that when simultaneously scanning the photon energy ... More
Aggregate Characterization of User Behavior in Twitter and Analysis of the Retweet GraphFeb 11 2014Most previous analysis of Twitter user behavior is focused on individual information cascades and the social followers graph. We instead study aggregate user behavior and the retweet graph with a focus on quantitative descriptions. We find that the lifetime ... More
A large accretion disk of extreme eccentricity in the TDE ASASSN-14liJul 24 2018Aug 02 2018In the canonical model for tidal disruption events (TDEs), the stellar debris circularizes quickly to form an accretion disk of size about twice the orbital pericenter of the star. Most TDEs and candidates discovered in the optical/UV have broad optical ... More
Modeling response time with power-law distributionsOct 14 2015Understanding the properties of response time distributions is a long-standing problem in cognitive science. We provide a tutorial overview of several contemporary models that assume power law scaling is a plausible description of the skewed heavy tails ... More
Black hole mass and accretion rate of Active Galactic NucleiMay 05 2006The determination of the central black hole mass is crucial to the understanding of AGN physics. In this paper we briefly review some methods that are currently used to estimate the black hole mass of AGNs. Particularly we demonstrate the importance of ... More
Black hole mass estimation with a relation between the BLR size and emission line luminosity of AGNMar 10 2004An empirical relation between the broad line region (BLR) size and optical continuum luminosity is often adopted to estimate the BLR size and then the black hole mass of AGNs. However, optical luminosity may not be a good indicator of photoionizing luminosity ... More
Spin squeezing: transforming one-axis-twisting into two-axis-twistingMay 03 2011Squeezed spin states possess unique quantum correlation or entanglement that are of significant promises for advancing quantum information processing and quantum metrology. In recent back to back publications [C. Gross \textit{et al, Nature} \textbf{464}, ... More
Controlling the transport of single photons by tuning the frequency of either one or two cavities in an array of coupled cavitiesSep 15 2009Apr 14 2010We theoretically study how to control transport, bound states, and resonant states of a single photon in a one-dimensional coupled-cavity array. We find that the transport of a single photon in the cavity array can be controlled by tuning the frequency ... More
Curvature of the spectral energy distribution, the dominant process for inverse Compton component and other jet properties in Fermi 2LAC blazarsSep 19 2016We fit the spectral energy distributions (SEDs) of members of a large sample of Fermi 2LAC blazars to synchrotron and inverse Compton (IC) models. Our main results are as follows. (i) As suggested by previous works, the correlation between peak frequency ... More
Observation of Andreev Surface Bound States in the 3-K phase Region of Sr_2RuO_4Jan 26 2001Jun 12 2001The tunneling spectrum of the superconducting phase with T_c ~ 3.0 K has been measured in the Ru-embedded region of Sr_2RuO_4 using cleaved junctions. A sharp zero-bias conductance peak (ZBCP) has been observed below 3 K. All characteristics of this ZBCP ... More
Estimating black hole masses of blazarsNov 29 2010Estimating black hole masses of blazars is still a big challenge. Because of the contamination of jets, using the previously suggested size -- continuum luminosity relation can overestimate the broad line region (BLR) size and black hole mass for radio-loud ... More
Disk origin of broad optical emission lines of the TDE candidate PTF09djlOct 11 2017An otherwise dormant supermassive black hole (SMBH) in a galactic nucleus flares up when it tidally disrupts a star passing by. Most of the tidal disruption events (TDEs) and candidates discovered in the optical/UV have broad optical emission lines with ... More
Superconductivity at 44 K in K intercalated FeSe system with excess FeMar 07 2012Feb 04 2013We report here that a new superconducting phase with much higher Tc has been found in K intercalated FeSe compound with excess Fe. We successfully grew crystals by precisely controlling the starting amount of Fe. Besides the superconducting (SC) transition ... More
Effective Hamiltonian approach to the Kerr nonlinearity in an optomechanical systemMay 27 2008Sep 13 2009Using the Born-Oppenheimer approximation, we derive an effective Hamiltonian for an optomechanical system that leads to a nonlinear Kerr effect in the system's vacuum. The oscillating mirror at one edge of the optomechanical system induces a squeezing ... More
Electrical Control of Dynamic Spin Splitting Induced by Exchange Interaction as Revealed by Time Resolved Kerr Rotation in a Degenerate Spin-Polarized Electron GasNov 04 2007Mar 25 2008The manipulation of spin degree of freedom have been demonstrated in spin polarized electron plasma in a heterostructure by using exchange-interaction induced dynamic spin splitting rather than the Rashba and Dresselhaus types, as revealed by time resolved ... More
Anomalous Hall Effect in Fe/Gd BilayersJan 11 2010Apr 13 2010Non-monotonic dependence of anomalous Hall resistivity on temperature and magnetization, including a sign change, was observed in Fe/Gd bilayers. To understand the intriguing observations, we fabricated the Fe/Gd bilayers and single layers of Fe and Gd ... More
Low frequency noise statistics for the breakdown characterization of ultra-thin gate oxidesAug 16 2005We have investigated the statistics of low frequency noise in the tunneling current of ultrathin oxides (2.5nm-4nm) in metal oxide semiconductor capacitors as a function of the applied voltage stress. The statistical analysis includes (i) non-Gaussianity ... More
The Mason Test: A Defense Against Sybil Attacks in Wireless Networks Without Trusted AuthoritiesMar 24 2014Wireless networks are vulnerable to Sybil attacks, in which a malicious node poses as many identities in order to gain disproportionate influence. Many defenses based on spatial variability of wireless channels exist, but depend either on detailed, multi-tap ... More
Weighing black holes in radio-loud AGNsJan 09 2007Because of the contamination of jets, using the size -- continuum luminosity relation can overestimate the broad line region (BLR) size and black hole mass for radio-loud AGNs. We propose a new relation between the BLR size and $H_{\beta}$ emission line ... More
Transverse Beam Envelope Measurements and the Limitations of the 3-Screen Emittance Method for Space-Charge Dominated BeamsOct 01 2004In its normal mode of operation the Argonne Wakefield Accelerator Facility uses a high charge (10-100 nC), short pulse (3-5 psec) drive bunch to excite high-gradient accelerating fields in various slow-wave structures. To generate this bunch, we designed ... More
Cavity optomechanical coupling assisted by an atomic gasMar 06 2008We theoretically study a cavity filled with atoms, which provides the optical-mechanical interaction between the modified cavity photonic field and a movable mirror at one end. We show that the cavity field ``dresses'' these atoms, producing two types ... More
Semiclassical Time Evolution of the Holes from Luttinger HamiltonianOct 17 2004We study the semi-classical motion of holes by exact numerical solution of the Luttinger model. The trajectories obtained for the heavy and light holes agree well with the higher order corrections to the abelian and the non-abelian adiabatic theories ... More
Image reconstruction by domain transform manifold learningApr 28 2017Image reconstruction plays a critical role in the implementation of all contemporary imaging modalities across the physical and life sciences including optical, MRI, CT, PET, and radio astronomy. During an image acquisition, the sensor encodes an intermediate ... More
Hurst parameter analysis of radio pulsar timing noiseOct 08 2009We present an analysis of timing residual (noise) of 54 pulsars obtained from 25-m radio telescope at Urumqi Observatory with a time span of 5~8 years, dealing with statistics of the Hurst parameter. The majority of these pulsars were selected to have ... More
The BCS-like gap in superconductor SmFeAsO_0.85F_0.15May 29 2008Since the discovery of superconductivity in the cuprates two decades ago, it has been firmly established that the CuO_2 plane is consequential for high T_C superconductivity and a host of other very unusual properties. A new family of superconductors ... More
Excitations of Ellipsoid Packings near JammingApr 09 2009Jun 04 2009We study the vibrational modes of three-dimensional jammed packings of soft ellipsoids of revolution as a function of particle aspect ratio $\epsilon$ and packing fraction. At the jamming transition for ellipsoids, as distinct from the idealized case ... More
KxFe2-ySe2 single crystals: Floating-zone growth, Transport and Structural propertiesJan 04 2012Single crystals of superconducting KxFe2-ySe2 have been grown with the optical floating-zone technique under application of 8 bar of argon pressure. We found that large and high quality single crystals with dimensions of ~\varnothing6 \times 10 mm could ... More
Gapless spin-liquid ground state in the $S = 1/2$ kagome antiferromagnetOct 15 2016Feb 28 2017Frustrated quantum magnetism has moved to the forefront of physics research, posing fundamental questions concerning quantum disordered states, entanglement, topology and the nature of the quantum wavefunction. The defining problem in the field is one ... More
Gapless spin-liquid ground state in the $S = 1/2$ kagome antiferromagnetOct 15 2016Frustrated quantum magnetism has moved to the forefront of physics research, posing fundamental questions concerning quantum disordered states, entanglement, topology and the nature of the quantum wavefunction. The defining problem in the field is one ... More
Growth and superconducting transition of $Pr_{1-x} Ca_x Ba_2 Cu_3 O_{7-δ}$ ($x\approx0.5$) epitaxial thin filmsSep 10 2004Pr$_{1-x}$Ca$_x$Ba$_2$Cu$_3$O$_{7-\delta}$($x\approx$0.5) thin films have been grown on SrTiO$_3$ and YSZ substrates by the pulsed laser ablation. The substrate temperature dependence of orientation and superconducting poperties were systematically studied. ... More
Microwave fields driven domain wall motions in antiferromagnetic nanowiresJan 21 2018In this work, we study the microwave field driven antiferromagnetic domain wall motion in an antiferromagnetic nanowire, using the numerical calculations based on a classical Heisenberg spin model. We show that a proper combination of a static magnetic ... More
Monte-Carlo study of the MRPC prototype for the upgrade of BESIIIMay 07 2016A GEANT4-based simulation is developed for the endcap time of flight (ETOF) upgrade based on multi-gap resistive plate chambers (MRPC) for the BESIII experiment. The MRPC prototype and the simulation method are described. Using a full Monte-Carlo simulation, ... More
Test of source selection for constructing a more stable and uniform celestial reference frameDec 06 2016We aim to evaluate the possibility of improving the ICRS realization starting from the ICRF2 catalogue by investigating the coordinate time series of radio sources observed by VLBI between 1979 and 2016. Sources with long observational history are selected ... More
Coulomb focusing at above-threshold ionization in elliptically polarized mid-infrared strong laser fieldsSep 26 2011Jan 31 2012The role of Coulomb focusing in above-threshold ionization in an elliptically polarized mid-infrared strong laser field is investigated within a semiclassical model incorporating tunneling and Coulomb field effects. It is shown that Coulomb focusing up ... More
Analytical Formulae for the Loss Factors and Wakefields of a Rectangular Accelerating StructureJun 03 2013Wakefields in a rectangular accelerating structure can be calculated in time domain by directly solving Maxwell's equations by a 3D code. In this paper, we will give analytical formulae to calculate the synchronous modes' loss factors. From these analytical ... More
Anisotropic Localization Effect in Layered MaterialsDec 18 1995We investigate localization properties in the highly anisotropic and intrinsically disordered layered material, which is analogous to high-Tc cuprates. By varying the anisotropy of the system which is parameterized by the interlayer hopping $tp$, we find ... More
Comment on "Superhard Semiconducting Optically Transparent High Pressure Phase of Boron"Aug 14 2009Dec 27 2010This Comment points out a number of errors in the recent paper by Zarechnaya, Dubrovinskaia, Dubrovinsky, et al. (Phys. Rev. Lett. 102, 185501 (2009)). Results and conclusions presented by Zarechnaya et al. (2009) are either incorrect or have been presented ... More
A new superconductor of cuprates with unique featuresAug 28 2018The mechanism of superconductivity of cuprates remains one of the biggest challenges in condensed matter physics. High-Tc cuprates crystallize into layered perovskite structure typically featured with copper-oxygen octahedra forming corner shared network. ... More
Origin of Unexpected Low Energy Structure in Photoelectron Spectra Induced by Mid-Infrared Strong Laser FieldsJul 29 2010Using a semiclassical model which incorporates tunneling and Coulomb field effects, the origin of the unexpected low-energy structure (LES) in above-threshold ionization spectrum observed in recent experiments [C. I. Blaga et al., Nature Phys. {\bf 5}, ... More
Wavelength and intensity dependence of multiple forward scattering at above-threshold ionization in mid-infrared strong laser fieldsNov 08 2010Mar 09 2011The nonperturbative role of multiple forward scattering for Coulomb focusing in mid-infrared laser fields and its dependence on a laser intensity and wavelength are investigated for low-energy photoelectrons at above-threshold ionization. We show that ... More
Monoenergetic proton beams accelerated by circularly polarized laser with thin solid foilsNov 22 2007Dec 22 2007The acceleration of ions in the interaction of circular polarized laser pulses with overdense plasmas is investigated. For circular polarization laser pulses, the quasi-equilibrium for electrons is established due to the light pressure and the electrostatic ... More
Elastic and electronic properties of fluorite RuO_2 from first principleApr 26 2012The elastic, thermodynamic, and electronic properties of fluorite RuO_2 under high pressure are investigated by plane-wave pseudopotential density functional theory. The optimized lattice parameters, elastic constants, bulk modulus, and shear modulus ... More
Large Gap Topological Insulator Bi2Te3 with a Single Dirac Cone on the SurfaceApr 12 2009We investigate the surface state of Bi$_2$Te$_3$ using angle resolved photoemission spectroscopy (ARPES) and transport measurements. By scanning over the entire Brillouin zone (BZ), we demonstrate that the surface state consists of a single non-degenerate ... More
Unit cell orientation of tetragonal-like BiFeO$_3$ thin films grown on highly miscut LaAlO$_3$ substratesDec 13 2013Synchrotron and lab-scale x-ray diffraction shows that tetragonal-like T'-BiFeO3 films on miscut LaAlO3 substrates (miscut < 5 deg) exhibit (00l)-planes tilted away from those of the substrate as predicted by the "Nagai model" (except for miscut <0.2 ... More
Superconductivity in alkali-earth metals doped phenanthreneOct 25 2011We discover superconductivity in alkali-earth metals doped phenanthrene. The superconducting critical temperatures \emph{T}$_c$ are 5.6 K and 5.4 K for Sr$_{1.5}$phenanthrene and Ba$_{1.5}$phenanthrene, respectively. The shielding fraction of Ba$_{1.5}$phenanthrene ... More
Spin-enhanced organic bulk heterojunction photovoltaic solar cellsMar 04 2013Recently, much effort has been devoted to improve the efficiency of organic photovoltaic solar cells based on blends of donors and acceptors molecules in bulk heterojunction architecture. One of the major losses in organic photovoltaic devices has been ... More
Pulse profiles and timing of PSR J1757$-$2421Dec 08 2016Pulse arrival time measurements over fourteen years with the Nanshan 25-m and Parkes 64-m radio telescopes have been used to determine the average profile and timing properties for PSR J1757$-$2421 (B1754$-$24). Analysis of the radio profile data shows ... More
Exciton Valley Dynamics probed by Kerr Rotation in WSe2 MonolayersJul 22 2014We have experimentally studied the pump-probe Kerr rotation dynamics in WSe$_2$ monolayers. This yields a direct measurement of the exciton valley depolarization time $\tau_v$. At T=4K, we find $\tau_v\approx 6$ps, a fast relaxation time resulting from ... More
High Pressure Structural Stability of Multiferroic Hexagonal REMnO3Oct 04 2010May 03 2011Structural changes in REMnO3 (RE= Y, Ho, Lu) under high pressure were examined by synchrotron x-ray diffraction methods at room temperature. Compression occurs more readily in the ab plane than along the c-axis. Under hydrostatic pressure (~11 GPa), the ... More
A Neutron Scattering Study of the H-T Phase Diagram of the Bond Frustrated ZnCr2S4Jun 01 2014Detailed neutron scattering measurements on the bond frustrated magnet ZnCr2S4 reveal a rich H-T phase diagram. The field dependence of the two subsequent antiferromagnetic transitions follows closely that of recently reported structural instabilities, ... More
In Vivo Wireless Channel ModelingFeb 21 2019In this chapter, the state of the art of in vivo wireless channel characterization has been presented. Various studies described in the literature are dedicated to the in vivo communication channel, and they consider different parameters in studying various ... More
Tunable terahertz radiation from graphene induced by moving electronsFeb 12 2014Based on a structure consisting of a single graphene layer situated on a periodic dielectric grating, we show theoretically that intense terahertz (THz) radiations can be generated by an electron bunch moving atop the graphene layer. The underlying physics ... More
Ashkin-Teller criticality and weak-first-order behavior of phase transition to four-fold degenerate state in two-dimensional frustrated Ising antiferromagnetsJun 16 2017We study the thermal phase transitions of the four-fold degenerate phases (the plaquette and single stripe states) in two-dimensional frustrated Ising model on the Shastry-Sutherland lattice using Monte Carlo simulations. The critical Ashkin-Teller-like ... More
Resonance Measurement of Nonlocal Spin Torque in a Three-Terminal Magnetic DeviceMar 15 2012Jul 24 2012A pure spin current generated within a nonlocal spin valve can exert a spin transfer torque on a nanomagnet. This nonlocal torque enables new design schemes for magnetic memory devices that do not require the application of large voltages across tunnel ... More
Determination of Superconducting Gap of SmFeAsFxO1-x Superconductors by Andreev Reflection SpectroscopyFeb 23 2009The superconducting gap in FeAs-based superconductor SmFeAs(O1-xFx) (x = 0.15 and 0.30) and the temperature dependence of the sample with x = 0.15 have been measured by Andreev reflection spectroscopy. The intrinsic superconducting gap is independent ... More
Unconventional Magnetism in a Nitrogen-Based Analogue of Cupric OxideMay 09 2011Jun 30 2011We have investigated the magnetic properties of CuNCN, the first nitrogen-based analogue of cupric oxide, CuO. Our muon spin relaxation, nuclear magnetic resonance and electron spin resonance studies reveal that classical magnetic ordering is absent down ... More
Spin glass state and enhanced spiral phase in doped delafossite oxide CuCrO2Jun 24 2016In this work, we study the doping effects on the magnetic states of CuCrO2 based on the classical frustrated spin model [Lin et al., Phys. Rev. B 89, 220405(R) (2014)]. Several experimental observations can be well reproduced by the Monte Carlo simulations ... More
Predicting the amount of hydrogen stripped by the supernova explosion for SN 2002cx-like SNe IaOct 15 2013Oct 30 2013The most favored progenitor scenarios for Type Ia supernovae (SNe Ia) involve the single-degenerate (SD) scenario and the double-degenerate scenario. The absence of stripped hydrogen (H) in the nebular spectra of SNe Ia challenges the SD progenitor models. ... More
Dynamics and stability of relativistic GRB blast wavesSep 07 2010In gamma-ray-bursts (GRB), ultra-relativistic blast waves are ejected into the circumburst medium. We analyse in unprecedented detail the deceleration of a self-similar Blandford-McKee blast wave from a Lorentz factor 25 to the nonrelativistic Sedov phase. ... More
Decelerating relativistic two-component jetsOct 02 2009Transverse stratification is a common intrinsic feature of astrophysical jets. There is growing evidence that jets in radio galaxies consist of a fast low density outflow at the jet axis, surrounded by a slower, denser, extended jet. The inner and outer ... More
Reconstruction of diagonal elements of density matrix using maximum likelihood estimationMay 18 1998The data of the experiment of Schiller et al., Phys. Rev. Lett. 77 (1996) 2933, are alternatively evaluated using the maximum likelihood estimation. The given data are fitted better than by the standard deterministic approach. Nevertheless, the data are ... More
Entangled states and collective nonclassical effects in two-atom systemsFeb 11 2003We propose a review of recent developments on entanglement and non-classical effects in collective two-atom systems and present a uniform physical picture of the many predicted phenomena. The collective effects have brought into sharp focus some of the ... More
Conditional symmetry and spectrum of the one-dimensional Schrödinger equationJun 06 1996We develop an algebraic approach to studying the spectral properties of the stationary Schr\"odinger equation in one dimension based on its high order conditional symmetries. This approach makes it possible to obtain in explicit form representations of ... More
Energy loss effects on heavy quark production in heavy-ion collisions at $\sqrt{s} = 5.5$ $A$TeVAug 03 1998We study the effect of energy loss on charm and bottom quarks in high-energy heavy-ion collisions including hadronization, longitudinal expansion and partial thermalization. We consider in detail the detector geometry and single lepton energy cuts of ... More
The Problem of Projecting the Origin of Euclidean Space onto the Convex PolyhedronMay 17 2016This paper is aimed at presenting a systematic survey of the existing now different formulations for the problem of projection of the origin of the Euclidean space onto the convex polyhedron (PPOCP). In the present paper, there are investigated the reduction ... More
(2+1) gravity for higher genus in the polygon modelDec 07 2003May 10 2004We construct explicitly a (12g-12)-dimensional space P of unconstrained and independent initial data for 't Hooft's polygon model of (2+1) gravity for vacuum spacetimes with compact genus-g spacelike slices, for any g >= 2. Our method relies on interpreting ... More