Application of asymptotic iteration method to a deformed well problem
The asymptotic iteration method (AIM) is used to obtain the quasi-exact solutions of the Schrödinger equation with a deformed well potential. For arbitrary potential parameters, a numerical aspect of AIM is also applied to obtain highly accurate energy eigenvalues. Additionally, the perturbation expansion, based on the AIM approach, is utilized to obtain simple analytic expressions for the energy eigenvalues.
New variable separation solutions for the generalized nonlinear diffusion equations
Bright and dark soliton solutions for some nonlinear fractional differential equations
Geometric global quantum discord of two-qubit states
We consider the geometric global quantum discord (GGQD) of two-qubit systems. By analyzing the symmetry of geometric global quantum discord we give an approach for deriving analytical formulae of the extremum problem which lies at the core of computing the GGQD for arbitrary two-qubit states. Furthermore, formulae of GGQD of arbitrary two-qubit states and some concrete examples are presented.
Hybrid entanglement concentration assisted with single coherent state
Entanglement detection in the mixed-spin Ising-XY model
In the present work, we initially verify anisotropy effect on the heat capacity of a mixed-three-spin (1/2,1,1/2) system (where spins (1/2,1/2) have XY interaction and spins (1,1/2) have Ising interaction together) at finite temperatures, then, the pairwise entanglement for spins (1/2,1/2), by means of negativity (as a measure of entanglement) as a function of the temperature T, homogeneous magnetic field B, and anisotropy parameter γ is investigated. In addition, we show that one can find magnetic phase transition points for the spins (1/2,1/2) at finite temperatures and understand properly their behavior with respect to the magnetic field and the anisotropy parameter, via the negativity function. An interval of the magnetic field from the negativity diagram of the spins (1/2,1/2) is presented in which quantum phase transition occurs for the tripartite mixed-three-spin system. Finally, some new interesting entanglement witnesses are introduced by using non-degenerate perturbation theory for the mixed-three-spin system.
Fidelity spectrum: A tool to probe the property of a quantum phase
Multi-valued responses and dynamic stability of a nonlinear vibro-impact system with a unilateral non-zero offset barrier
Hysteresis-induced bifurcation and chaos in a magneto-rheological suspension system under external excitation
Empirical investigation of topological and weighted properties of a bus transport network from China
STED microscopy based on axially symmetric polarized vortex beams
Ab initio investigation of sulfur monofluoride and its singly charged cation and anion in their ground electronic state
The SF radical and its singly charged cation and anion, SF+ and SF-, have been investigated on the MRCI/aug-cc-pVXZ (X = Q, 5, 6) levels of theory with Davidson correction. Both the core-valence correlation and the relativistic effect are considered. The extrapolating to the complete basis set (CBS) limit is adopted to remove the basis set truncation error. Geometrical parameters, potential energy curves (PECs), vibrational energy levels, spectroscopic constants, ionization potentials, and electron affinities of the ground electronic state for all these species are obtained. The information with respect to molecular characteristics of the SFn (n=-1, 0, +1) systems derived in this work will help to extend our knowledge and to guide further experimental or theoretical researches.
γ-and α-Ce phase diagram: First-principle calculation
Extreme ultraviolet and soft x-ray spectral lines in Rb XXIX
Influence of the interaction volume on the kinetic energy resolution of a velocity map imaging spectrometer
We investigate the influence of the interaction volume on the energy resolution of a velocity map imaging spectrometer. The simulation results show that the axial interaction size has a significant influence on the resolution. This influence is increased for a higher kinetic energy. We further show that the radial interaction size has a minor influence on the energy resolution for the electron or ion with medium energy, but it is crucial for the resolution of the electron or ion with low kinetic energy. By tracing the flight trajectories we show how the electron or ion energy resolution is influenced by the interaction size.
Quantum and semiclassical studies on photodetachment cross sections of H- in a harmonic potential
The photodetachment cross section of H- in a linear harmonic oscillator potential is investigated. This system provides a rare example that can be studied analytically by both quantum and semiclassical methods with some approximations. The formulas of the cross section for different laser polarization directions are explicitly derived by both the traditional quantum approach and closed-orbit theory. In the traditional quantum approach, we calculate the cross sections in coordinate representation and momentum representation, and get the same formulas. We compare the quantum formulas with closed-orbit theory formulas, and find that when the detachment electron energy is larger than 3/2ħω, where ω is the frequency of the oscillator potential, the quantum results are shown to be in good agreement with the semiclassical results.
Electron excitation from ground state to first excited state: Bohmian mechanics method
Accurate prediction of interference minima in linear molecular harmonic spectra by a modified two-center model
We demonstrate that the interference minima in the linear molecular harmonic spectra can be accurately predicted by a modified two-center model. Based on systematically investigating the interference minima in the linear molecular harmonic spectra by the strong-field approximation (SFA), it is found that the locations of the harmonic minima are related not only to the nuclear distance between the two main atoms contributing to the harmonic generation, but also to the symmetry of the molecular orbital. Therefore, we modify the initial phase difference between the double wave sources in the two-center model, and predict the harmonic minimum positions consistent with those simulated by SFA.
Production of projectile and target K-vacancy in near-symmetric collisions of 60-100 MeV Cu9+ ions with thin Zn target
Spoof surface plasmon-based bandpass filter with extremely wide upper stopband
Theoretical studies on particle shape classification based on simultaneous small forward angle light scattering and aerodynamic sizing
High-power electro-optic switch technology based on novel transparent ceramic
Second-order interference of two independent and tunable single-mode continuous-wave lasers
Electromagnetically induced transparency in a Zeeman-sublevels Λ-system of cold 87Rb atoms in free space
We report the experimental investigation of electromagnetically induced transparency (EIT) in a Zeeman-sublevels Λ-type system of cold 87Rb atoms in free space. We use the Zeeman substates of the hyperfine energy states 52 S1/2, F=2 and 52 P3/2, F'=2 of 87Rb D2 line to form a Λ-type EIT scheme. The EIT signal is obtained by scanning the probe light over 1 MHz in 4 ms with an 80 MHz arbitrary waveform generator. More than 97% transparency and 100 kHz EIT window are observed. This EIT scheme is suited for an application of pulsed coherent storage atom clock (Yan B, et al. 2009 Phys. Rev. A 79 063820).
Influence of Fano interference and incoherent processes on optical bistability in a four-level quantum dot nanostructure
Role of Fano interference and incoherent pumping field on optical bistability in a four-level designed InGaN/GaN quantum dot nanostructure embedded in a unidirectional ring cavity are analyzed. It is found that intensity threshold of optical bistability can be manipulated by Fano interference. It is shown that incoherent pumping fields make the threshold of optical bistability behave differently by Fano interference. Moreover, in the presence of Fano interference the medium becomes phase-dependent. Therefore, the relative phase of applied fields can affect the behaviors of optical bistability and intensity threshold can be controlled easily.
Experimental study of electro-optical Q-switched pulsed Nd:YAG laser
Passively Q-switched dual-wavelength Yb:LSO laser based on tungsten disulphide saturable absorber
We demonstrate a passively Q-switched Yb:LSO laser based on tungsten disulphide (WS2) saturable absorber operating at 1034 nm and 1056 nm simultaneously. The saturable absorbers were fabricated by spin coating method. With low speed, the WS2 nanoplatelets embedded in polyvinyl alcohol could be coated on a BK7 glass substrate coated with high-refractive-index thin polymer. The shortest pulse width of 1.6 μs with a repetition rate of 76.9 kHz is obtained. As the pump power increases to 9 W, the maximum output power is measured to be 250 mW, corresponding to a single pulse energy of 3.25 μJ. To the best of our knowledge, this is the first time to obtain dual-wavelength Q-switched solid-state laser using few-layer WS2 nanoplatelets.
Theoretical analysis of the electromagnetic field inside an anomalous-dispersion microresonator under synthetical pump
Theoretical simulation of a novel birefringent photonic crystal fiber with surface plasmon resonance around 1300 nm
In this paper, a novel birefringent photonic crystal fiber (PCF) with the silver-coated and liquid-filled air-holes along the vertical plane is designed. Simulation results show that the thickness of silver layer, the sizes of holes, and the refractive index of liquid strongly strengthen the gaps between two polarized directions. The surface plasmon resonance peak along y axis can be up to 675.8 dB/cm at 1.33 μm. The proposed PCF has important application in polarization devices, such as filters and beam splitters.
Wave propagation in beams with anti-symmetric piezoelectric shunting arrays
Discrete element crowd model for pedestrian evacuation through an exit Hot!
A series of accidents caused by crowds within the last decades evoked a lot of scientific interest in modeling the movement of pedestrian crowds. Based on the discrete element method, a granular dynamic model, in which the human body is simplified as a self-driven sphere, is proposed to simulate the characteristics of crowd flow through an exit. In this model, the repulsive force among people is considered to have an anisotropic feature, and the physical contact force due to body deformation is quantified by the Hertz contact model. The movement of the human body is simulated by applying the second Newton's law. The crowd flow through an exit at different desired velocities is studied and simulation results indicated that crowd flow exhibits three distinct states, i.e., smooth state, transition state and phase separation state. In the simulation, the clogging phenomenon occurs more easily when the desired velocity is high and the exit may as a result be totally blocked at a desired velocity of 1.6 m/s or above, leading to faster-to-frozen effect.
Single-pinhole diffraction of few-cycle isolated attosecond pulses with a two-color field
Spectral and ion emission features of laser-produced Sn and SnO2 plasmas
Enhanced laser-induced plasma channels in air
Electric and plasma characteristics of RF discharge plasma actuation under varying pressures
Theoretical analysis of the influence of flexoelectric effect on the defect site in nematic inversion walls
Based on the experimental phenomena of flexoelectric response at defect sites in nematic inversion walls conducted by Kumar et al., we gave the theoretical analysis using the Frank elastic theory. When a direct-current electric field normal to the plane of the substrate is applied to the parallel aligned nematic liquid crystal cell with weak anchoring, the rotation of ± 1 defects in the narrow inversion walls can be exhibited. The free energy of liquid crystal molecules around the +1 and-1 defect sites in the nematic inversion walls under the electric field was formulated and the electric-field-driven structural changes at the defect site characterized by polar and azimuthal angles of the local director were simulated. The results reveal that the deviation of azimuthal angle induced by flexoelectric effect are consistent with the switching of extinction brushes at the +1 and-1 defects obtained in the experiment conducted by Kumar et al.
Size effect in the melting and freezing behaviors of Al/Ti core-shell nanoparticles using molecular dynamics simulations
Mechanism of floating body effect mitigation via cutting off source injection in a fully-depleted silicon-on-insulator technology
Energetics of carbon and nitrogen impurities and their interactions with vacancy in vanadium
Density functional theory study of structural, electronic, and thermal properties of Pt, Pd, Rh, Ir, Os and PtPdX (X = Ir, Os, and Rh) alloys
Boron diffusion in bcc-Fe studied by first-principles calculations
Image potential states mediated STM imaging of cobalt phthalocyanine on NaCl/Cu(100)
Electronic properties and topological phases of ThXY (X=Pb, Au, Pt and Y= Sb, Bi, Sn) compounds
Electronic structures of efficient MBiO3 (M = Li, Na, K, Ag) photocatalyst
Tunable localized surface plasmon resonances in one-dimensional h-BN/graphene/h-BN quantum-well structure
Suppression of Andreev conductance in a topological insulator-superconductor nanostep junction
Van der Waals heterostructure of phosphorene and hexagonal boron nitride: First-principles modeling
A subwavelength metal-grating assisted sensor of Kretschmann style for investigating the sample with high refractive index
Resonant Andreev reflection in a normal-metal/quantum-dot/superconductor system with coupled Majorana bound states
Andreev reflection (AR) in a normal-metal/quantum-dot/superconductor (N-QD-S) system with coupled Majorana bound states (MBSs) is investigated theoretically. We find that in the N-QD-S system, the AR can be enhanced when coupling to the MBSs is incorporated. Fano line-shapes can be observed in the AR conductance spectrum when there is an appropriate QD-MBS coupling or MBS-MBS coupling. The AR conductance is always e2/2h at the zero Fermi energy point when only QD-MBSs coupling is considered. In addition, the resonant AR occurs when the MBS-MBS coupling roughly equals to the QD energy level. We also find that an AR antiresonance appears when the QD energy level approximately equals to the sum of the QD-MBS coupling and the MBS-MBS coupling. These features may serve as characteristic signatures for the probe of MBSs.
Theoretical investigation of structural and optical properties of semi-fluorinated bilayer graphene
Fabrication and characterization of the normally-off N-channel lateral 4H-SiC metal-oxide-semiconductor field-effect transistors
Charge recombination mechanism to explain the negative capacitance in dye-sensitized solar cells
Growth mechanism of atomic-layer-deposited TiAlC metal gatebased on TiCl4 and TMA precursors
Fractional-dimensional approach for excitons in GaAsfilms on AlxGa1-xAs substrates
Effect of exchange coupling on magnetic property in Sm-Co/α-Fe layered system
Preparation and characterization of Sr0.5Ba0.5Nb2O6 glass-ceramic on piezoelectric properties
Design of a multiband terahertz perfect absorber
High-temperature Raman spectroscopic study of vanadoborate Na3VO2B6O11
Second harmonic generation of metal nanoparticles under tightly focused illumination
Doping-driven orbital-selective Mott transition in multi-band Hubbard models with crystal field splitting
We have studied the doping-driven orbital-selective Mott transition in multi-band Hubbard models with equal band width in the presence of crystal field splitting. Crystal field splitting lifts one of the bands while leaving the others degenerate. We use single-site dynamical mean-field theory combined with continuous time quantum Monte Carlo impurity solver to calculate a phase diagram as a function of total electron filling N and crystal field splitting Δ. We find a large region of orbital-selective Mott phase in the phase diagram when the doping is large enough. Further analysis indicates that the large region of orbital-selective Mott phase is driven and stabilized by doping. Such models may account for the orbital-selective Mott transition in some doped realistic strongly correlated materials.
Velocity modulation of electron transport through a ferromagnetic silicene junction
We address velocity-modulation control of electron wave propagation in a normal/ferromagnetic/normal silicene junction with local variation of Fermi velocity, where the properties of charge, valley, and spin transport through the junction are investigated. By matching the wavefunctions at the normal-ferromagnetic interfaces, it is demonstrated that the variation of Fermi velocity in a small range can largely enhance the total conductance while keeping the current nearly fully valley-and spin-polarized. Further, the variation of Fermi velocity in ferromagnetic silicene has significant influence on the valley and spin polarization, especially in the low-energy regime. It may drastically reduce the high polarizations, which can be realized by adjusting the local application of a gate voltage and exchange field on the junction.
Band gap anomaly and topological properties in lead chalcogenides Hot!
Band gap anomaly is a well-known issue in lead chalcogenides PbX (X=S, Se, Te, Po). Combining ab initio calculations and tight-binding (TB) method, we have studied the band evolution in PbX, and found that the band gap anomaly in PbTe is mainly related to the high on-site energy of Te 5s orbital and the large s-p hopping originated from the irregular extended distribution of Te 5s electrons. Furthermore, our calculations show that PbPo is an indirect band gap (6.5 meV) semiconductor with band inversion at L point, which clearly indicates that PbPo is a topological crystalline insulator (TCI). The calculated mirror Chern number and surface states double confirm this conclusion.
High-pressure Raman study of solid hydrogen up to 300 GPa Hot!
The high-pressure behavior of solid hydrogen has been investigated by in situ Raman spectroscopy upon compression to 300 GPa at ambient temperature. The hydrogen vibron frequency begins to decrease after it initially increases with pressure up to 38 GPa. This softening behavior suggests the weakening of the intramolecular bond and the increased intermolecular interactions. Above 237 GPa, the vibron frequency softens very rapidly with pressure at a much higher rate than that of phase III, corresponding to transformation from phase III into phase IV. The phase transition sequence has been confirmed from phase I to phase III and then to phase IV at 208 and 237 GPa, respectively. Previous theoretical calculations lead to the proposal of an energetically favorable monoclinic C2/c structure for phase III and orthorhombic Pbcn structure for phase IV. Up to 304 GPa, solid hydrogen is not yet an alkali metal since the sample is still transparent.
Control of symmetric properties of metamorphic In0.27Ga0.73As layers by substrate misorientation
Reflection of thermoelastic wave on the interface of isotropic half-space and tetragonal syngony anisotropic medium of classes 4, 4/m with thermomechanical effect
Unifying the crystallization behavior of hexagonal and square crystals with the phase-field-crystal model
Linear theory of beam-wave interaction in double-slot coupled cavity travelling wave tube
Improved performance of polymer solar cells by using inorganic, organic, and doped cathode buffer layers
Effect of lateral structure parameters of SiGe HBTs on synthesized active inductors
Two-dimensional models of threshold voltage andsubthreshold current for symmetrical double-material double-gate strained Si MOSFETs
Evaluation of a gate-first process for AlGaN/GaN metal-oxide-semiconductor heterostructure field-effect transistors with low ohmic annealing temperature
Mobility enhancement of strained GaSb p-channel metal—oxide—semiconductor field-effect transistorswith biaxial compressive strain
Design and fabrication of multi-channel photodetector array monolithic with arrayed waveguide grating
Novel Fourier-based iterative reconstruction for sparse fan projection using alternating direction total variation minimization
Successive lag synchronization on dynamical networks with communication delay