Influence of random phase modulation on the imaging quality of computational ghost imaging
Dynamics of three nonisospectral nonlinear Schrödinger equations
Dynamics of three nonisospectral nonlinear Schrödinger equations (NNLSEs), following different time dependencies of the spectral parameter, are investigated. First, we discuss the gauge transformations between the standard nonlinear Schrödinger equation (NLSE) and its first two nonisospectral counterparts, for which we derive solutions and infinitely many conserved quantities. Then, exact solutions of the three NNLSEs are derived in double Wronskian terms. Moreover, we analyze the dynamics of the solitons in the presence of the nonisospectral effects by demonstrating how the shapes, velocities, and wave energies change in time. In particular, we obtain a rogue wave type of soliton solutions to the third NNLSE.
Evolutionary game dynamics of combining the Moran and imitation processes
Competitive and synergistic adsorption of binary volatile organic compound mixtures on activated carbon
Error-detected single-photon quantum routing using a quantum dot and a double-sided microcavity system
Based on a hybrid system consisting of a quantum dot coupled with a double-sided micropillar cavity, we investigate the implementation of an error-detected photonic quantum routing controlled by the other photon. The computational errors from unexpected experimental imperfections are heralded by single photon detections, resulting in a unit fidelity for the present scheme, so that this scheme is intrinsically robust. We discuss the performance of the scheme with currently achievable experimental parameters. Our results show that the present scheme is efficient. Furthermore, our scheme could provide a promising building block for quantum networks and distributed quantum information processing in the future.
Realization of t-bit semiclassical quantum Fourier transform on IBM's quantum cloud computer
Phase diagram of interacting fermionic two-leg ladder with pair hopping Hot!
We study the phase diagram of the interacting fermionic two-leg ladder, which is featured by pair hopping and interactions of singlet and triplet superconducting channels. By using Abelian bosonization method, we obtain the full phase diagram of our model. The superconducting triplet pairing phase is characterized by a fractional edge spin and interpreted as two Kitaev chains under the mean filed approximation. The pair hopping will give rise to spin-density-wave (SDW) orders and can also support Majorana edge modes in spin channel. At half filling, the resulting Majorana-SDW phase shows additional fractionalization in charge channel, and can be interpreted as two Su-Schrieffer-Heeger (SSH) chains in the mean field regime.
Nodes and layers PageRank centrality for multilayer networks
Energy feedback and synchronous dynamics of Hindmarsh-Rose neuron model with memristor
We analyze the energy aspects of single and coupled Hindmarsh-Rose (HR) neuron models with a quadratic flux controlled memristor. The energy function for HR neuron with memristor has been derived and the dynamics have been analyzed in the presence of various external stimuli. We found that the bursting mode of the system changes with external forcing. The negative feedback in Hamilton energy function effectively stabilizes the chaotic trajectories and controls the phase space. The Lyapunov exponents have been plotted to verify the stabilization of trajectories. The energy aspects during the synchronous dynamics of electrically coupled neurons have been analyzed. As the coupling strength increases, the average energy fluctuates and stabilizes at the point of synchronization. When the neurons are coupled via chemical synapse, the average energy variations show three important regimes:a fluctuating regime corresponding to the desynchronized, a stable region indicating synchronized and a linearly increasing regime corresponding to the amplitude death states have been observed. The synchronization transitions are verified by plotting the transverse Lyapunov exponents. The proposed method has a large number of applications in controlling coupled chaotic systems and in analyzing the energy change during various metabolic processes.
Design new chaotic maps based on dimension expansion
Dynamical stable-jump-stable-jump picture in a non-periodically driven quantum relativistic kicked rotor system
We study a non-periodically driven kicked rotor based on the one-dimensional quantum relativistic kicked rotor (QRKR). In our model, we add a small constant to the interval of the one-dimensional QRKR after each kick process. It is found that the momentum spreading is stable in finite kicked times, it then jumps up or down and becomes stable again. This interesting phenomenon is understood by quantum resonance. Moreover, the stable-jump-stable-jump phenomenon persists, even though the interval of kick process is randomly increased. This result means that the quantum resonance is independent of the periodic perturbation in the QRKR model.
One-dimensional mass transport with dynamic external potentials
Imaging alignment of rotational state-selected CH3I molecule
Reaction mechanism of D+ND→N+D2 and its state-to-state quantum dynamics
The quantum state-to-state calculations of the D+ND→N+D2 reaction are performed on a potential energy surface of 4A" state. The state-resolved integral and differential cross sections and product state distributions are calculated and discussed. It is found that the rotational distribution, rather than the vibrational distribution, of the product has an obvious inversion. Due to the fact that it is a small-impact-parameter collision, its product D2 is mainly dominated by rebound mechanism, which can lead to backward scattering at low collision energy. As the collision energy increases, the forward scattering and sideward scattering begin to appear. In addition, the backward collision is also found to happen at high collision energy, through which we can know that both the rebound mechanism and stripping mechanism exist at high collision energy.
Quantum photodetachment of hydrogen negative ion in a harmonic potential subjected to static electric field
Photodetachment of negative ions has attracted immense interest owing to its fundamental nature and practical implications with regard to technology. In this study, we explore the quantum dynamics of the photodetachment cross section of negative ion of hydrogen H- in the perturbed one dimensional linear harmonic potential via static electric field. To this end, the quantum formula for total photodetachment cross section of the H- ion is derived by calculating the dipole matrix element in spherical coordinates. In order to obtain the detached electron wave function, we have solved the time-independent Schrödinger wave equation for the perturbed Hamiltonian of the harmonic oscillator in momentum representation. To acquire the corresponding normalized final state detached electron wave function in momentum space, we have employed an approach analogous to the WKB (Wenzel-Kramers-Brillouin) approximation. The resulting analytical formula of total photodetachment cross section depicts interesting oscillator structure that varies considerably with incident-photon energy, oscillator potential frequency, and electric field strength as elucidated by the numerical results. The current problem having close analogy with the Stark effect in charged harmonic oscillator may have potential implications in atomic and molecular physics and quantum optics.
Angle-resolved spectra of the direct above-threshold ionization of diatomic molecule in IR+XUV laser fields
The direct above-threshold ionization (ATI) of diatomic molecules in linearly-polarized infrared and extreme ultraviolet (IR+XUV) laser fields is investigated by the frequency-domain theory based on the nonperturbative quantum electrodynamics. The destructive interference fringes on the angle-resolved ATI spectra, which are closely related to the molecular structure, can be well fitted by a simple predictive formula for any alignment of the molecular axis. By comparing the direct ATI spectra for monochromatic and two-color laser fields, we found that the XUV laser field can both raise the ionization probability and the kinetic energy of the ionized electron, while the infrared (IR) laser field can broaden the energy distribution of the ionized electron. Our results demonstrate that, by using IR+XUV two-color laser fields, the angle-resolved spectra of the direct ATI can image the structural information of molecules without considering the recollision process of the ionized electron.
Comparison of single-neutral-atom qubit between in bright trap and in dark trap
A single neutral atom is one of the most promising candidates to encode a quantum bit (qubit). In a real experiment, a single neutral atom is always confined in a micro-sized far off-resonant optical trap (FORT). There are generally two types of traps:red-detuned trap and blue-detuned trap. We experimentally compare the qubits encoded in “clock states” of single cesium atoms confined separately in either 1064-nm red-detuned (bright) trap or 780-nm blue-detuned (dark) trap:both traps have almost the same trap depth. A longer lifetime of 117 s and a longer coherence time of about 10 ms are achieved in the dark trap. This provides a direct proof of the superiority of the dark trap over the bright trap. The measures to further improve the coherence are discussed.
Nonreciprocal transmission of electromagnetic waves by three-layer magneto-optical mediums
Key design parameters and optimum method of medium- and high-velocity synchronous induction coilgun based on orthogonal experimental design
Propagation of a Pearcey beam in uniaxial crystals
An analytical propagation expression of a Pearcey beam in uniaxial crystals orthogonal to the optical axis is derived. The propagations of the Pearcey beam in the tourmaline and the quartz are investigated. The phase distribution and the angular momentum of the Pearcey beam in the tourmaline are also performed. The result shows that the positions of the auto-focusing and the inversion simply relate to the extraordinary refractive index of the crystals. In other words, we can choose the suitable crystals to adjust the positions of auto-focusing and inversion of the Pearcey beam to meet the actual needs.
Reflected and transmitted powers of arbitrarily polarized plane waves at interface between chiral and achiral media
Numerical study of optical trapping properties of nanoparticle on metallic film with periodic structure
Effect of thermally induced birefringence on high power picosecond azimuthal polarization Nd:YAG laser system
Amplitude and phase controlled absorption and dispersion of coherently driven five-level atom in double-band photonic crystal
Controllable photon echo phase induced by modulated pulses and chirped beat detection
Power of all-fiber amplifier increasing from 1030 W to 2280 W through suppressing mode instability by increasing the seed power
In this work, we investigate suppressing mode instability in detail by varying the seed power in a large mode area all-fiber amplifier with a fiber core diameter of 25 μm. The transverse mode instability (TMI) thresholds are systematically measured for different seed power. Our experimental results reveal that increasing the seed power has a positive influence on enhancing the output power before the TMI effect appears, and finally the TMI threshold is approximately doubled from 1030 W to 2280 W when the seed power is increased from 27 W to 875 W. Almost 84.7% slope efficiency is reached with different seed power before the TMI threshold power. During our operation, we also find that in this type of LMA fiber the beam quality of the amplifier is degraded gradually instead of a sudden change as the pump power increases.
Experimental and numerical investigation of mid-infrared laser in Pr3+-doped chalcogenide fiber
We report on a chalcogenide glass fiber doped with Pr3+ that can be used for commercialized 1.5-μm and 2-μm laser excitations by emitting broadband 3 μm-5.5 μm fluorescence, which is extruded into a preform and then drawn into a step-index fiber. The spectroscopic properties of the fiber and glass are reported, and the mid-infrared fiber lasers are also numerically investigated. Cascade lasing is employed to increase the inversion population of the upper laser level. The particle swarm approach is applied to optimize the fiber laser parameters. The output power can reach 1.28 W at 4.89-μm wavelength, with a pump power of 5 W, excitation wavelength at 2.04 μm, Pr3+ ion concentration at 4.22×1025 ions/m3, fiber length at 0.94 m, and fiber background loss at 3 dB/m.
Analysis of CV mode selected resonator based on vectorial eigenvector method
Nonlinear behavior of the population dynamics of three-level systems in the presence of single photon absorption
We numerically investigate the population dynamics in a single photon resonant three-level cascade and non-cascade energy level molecules at 532-nm wavelength. The time-dependent population in the energy levels in the presence of 100 ps (pico-second) and 100 ns (nano-second) laser pulses is described in the form of rate equations. We provide a brief idea of how the optical energy transfer takes place in the light-matter interaction and we also discuss the absorption as a function of pulse width and repetition rate. We also plot the z-scan transmittance curve as a function of number of excitation pulses participating in the absorption.
High-gain and low-distortion Brillouin amplification based on pump multi-frequency intensity modulation
Feasibility analysis for acquiring visibility based on lidar signal using genetic algorithm-optimized back propagation algorithm
Influence of low-temperature sulfidation on the structure of ZnS thin films
ZnS thin films were prepared by sulfuring zinc thin films at different sulfuration temperatures. The crystal structure, surface morphology, defects, and optical properties of the thin films were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), positron annihilation Doppler broadening, and UV-Vis spectrophotometer, respectively. It was found that the (200)-plane preferred orientation of the ZnS thin films changed to (111)-plane with increasing sulfidation temperature. Moreover, a number of large holes were generated at 420℃ and eliminated at 440℃. The concentration of defects was lowest when the sulfuration temperature was 440℃. The optical transmission of all samples was maintained at 60%-80% in the wavelength range of 400 nm-800 nm, and the band energy of the ZnS thin films was approximately 3.5 eV for all treatment temperatures except 430℃.
Laser-induced damage threshold in HfO2/SiO2 multilayer films irradiated by β-ray
Simultaneous polarization separation and switching for 100-Gbps DP-QPSK signals in backbone networks
Manipulation of acoustic wavefront by transmissive metasurface based on pentamode metamaterials
Ultrasonic backscatter characterization of cancellous bone using a general Nakagami statistical model Hot!
The goal of this study is to analyze the statistics of the backscatter signal from bovine cancellous bone using a Nakagami model and to evaluate the feasibility of Nakagami-model parameters for cancellous bone characterization. Ultrasonic backscatter measurements were performed on 24 bovine cancellous bone specimens in vitro and the backscatter signals were compensated for the frequency-dependent attenuation prior to the envelope detection. The statistics of the backscatter envelope were modeled using the Nakagami distribution. Our results reveal that the backscatter envelope mainly followed pre-Rayleigh distributions, and the deviations of the backscatter envelope from Rayleigh distribution decreased with increasing bone density. The Nakagami shape parameter (i.e., m) was significantly correlated with bone densities (R=0.78-0.81, p<0.001) and trabecular microstructures (|R|=0.46-0.78, p<0.05). The scale parameter (i.e., Ω) and signal-to-noise ratio (SNR) also yielded significant correlations with bone density and structural features. Multiple linear regressions showed that bone volume fraction (BV/TV) was the main predictor of the Nakagami parameters, and microstructure produced significantly independent contribution to the prediction of Nakagami distribution parameters, explaining an additional 10.2% of the variance at most. The in vitro study showed that statistical parameters derived with Nakagami model might be useful for cancellous bone characterization, and statistical analysis has potential for ultrasonic backscatter bone evaluation.
Aerodynamic actuation characteristics of radio-frequency discharge plasma and control of supersonic flow
Hydrodynamic binary coalescence of droplets under air flow in a hydrophobic microchannel
Numerical simulation on modulational instability of ion-acoustic waves in plasma
Effects of secondary electron emission on plasma characteristics in dual-frequency atmospheric pressure helium discharge by fluid modeling
A one-dimensional (1D) fluid simulation of dual frequency discharge in helium gas at atmospheric pressure is carried out to investigate the role of the secondary electron emission on the surfaces of the electrodes. In the simulation, electrons, ions of He+ and He2+, metastable atoms of Heast and metastable molecules of He2* are included. It is found that the secondary electron emission coefficient significantly influences plasma density and electric field as well as electron heating mechanisms and ionization rate. The particle densities increase with increasing SEE coefficient from 0 to 0.3 as well as the sheath's electric field and electron source. Moreover, the SEE coefficient also influences the electron heating mechanism and electron power dissipation in the plasma and both of them increase with increasing SEE coefficient within the range from 0 to 0.3 as a result of increasing of electron density.
Preliminary investigation on electrothermal instabilities in early phases of cylindrical foil implosions on primary test stand facility
Recent experiments on the implosions of 15-mm long and 2-μm thick aluminum liners having a diameter of 12.8 mm have been performed on the primary test stand (PTS) facility. The stratified structures are observed as alternating dark and light transverse stripes in the laser shadowgraph images. These striations perpendicular to the current flow are formed early in the implosion, i.e., at the stage when the bulk of the material mass was almost at rest. A two-dimensional (2D) magnetohydrodynamics (MHD) code is employed to simulate the behavior of liner dynamics in the early phases. It is found that the striations may be produced by the electrothermal instability (ETI) that results from non-uniform Joule heating due to the characteristic relation between the resistivity and the temperature. In 2D simulations, the stratified structures can be seen obviously in both density and temperature contours as the liner expands rapidly. By analyzing instability spectrum, the dominant wavelengths of the perturbations are 8.33 μm-20.0 μm, which agree qualitatively with the theoretical predictions. It is also interesting to show that ETI provides a significant seed to the subsequent magneto Rayleigh-Taylor (MRT) instability.
Enhanced structural and magnetic properties of microwave sintered Li-Ni-Co ferrites prepared by sol-gel method
Dynamically tunable optical properties in graphene-based plasmon-induced transparency metamaterials
Orientation dependence of elastic properties in orthorhombic Ca3Mn2O7
PEALD-deposited crystalline GaN films on Si (100) substrates with sharp interfaces
Effect of scanning speeds on electrochemical corrosion resistance of laser cladding TC4 alloy
1.8-kV circular AlGaN/GaN/AlGaN double-heterostructure high electron mobility transistor
Theoretical analytic model for RESURF AlGaN/GaN HEMTs
Influence of deep defects on electrical properties of Ni/4H-SiC Schottky diode
Low-energy (40 keV) proton irradiation of YBa2Cu3O7-x thin films:Micro-Raman characterization and electrical transport properties
To investigate the damage profiles of high-fluence low-energy proton irradiation on superconducting materials and related devices, Raman characterization and electrical transport measurement of 40-keV-proton irradiated YBa2Cu3O7-x (YBCO) thin films are carried out. From micro-Raman spectroscopy and x-ray diffraction studies, the main component of proton-radiation-induced defects is found to be the partial transition of superconducting orthorhombic phase to the semiconducting tetragonal phase and non-superconducting secondary phase. The results indicate that the defects induced in the conducting CuO2 planes, such as increased oxygen vacancies and interstitials, can result in an increase in the resistivity but a decrease in the transition temperature TC with the increase in the fluence of proton irradiation, which is confirmed in the electrical transport measurements. Especially, zero-resistance temperature TC0 is not observed at a fluence of 1015 p/cm2. Furthermore, the variation of activation energy U0 can be explained by the plastic-flux creep theory, which indicates that the plastic deformation and entanglement of vortices in a weakly pinned vortex liquid are caused by disorders of point-like defects. Point-like disorders are demonstrated to be the main contribution to the low-energy proton radiation damage in YBCO thin films. These disorders are likely to cause flux creep by thermally assisted flux flow, which may increase noise and reduce the precision of superconducting devices.
Phase diagrams and magnetic properties of the mixed spin-1 and spin-3/2 Ising ferromagnetic thin film:Monte Carlo treatment
Phase diagrams and magnetic properties of the mixed spin-1 and spin-3/2 Ising film with different single-ion anisotropies are investigated, by the use of Monte Carlo simulation based on heat bath algorithms. The effects of the crystal-fields and the surface coupling on the phase diagrams are investigated in detail and the obtained phase diagrams are presented. Depending on the Hamiltonian parameters, the system exhibits both second- and first-order phase transitions besides tricritical point, triple point, and isolated critical end point.
Unusual tunability of multiferroicity in GdMn2O5 by electric field poling far above multiferroic ordering point Hot!
The multiferroicity in the RMn2O5 family remains unclear, and less attention has been paid to its dependence on high-temperature (high-T) polarized configuration. Moreover, no consensus on the high-T space group symmetry has been reached so far. In view of this consideration, one may argue that the multiferroicity of RMn2O5 in the low-T range depends on the poling sequence starting far above the multiferroic ordering temperature. In this work, we investigate in detail the variation of magnetically induced electric polarization in GdMn2O5 and its dependence on electric field poling routine in the high-T range. It is revealed that the multiferroicity does exhibit qualitatively different behaviors if the high-T poling routine changes, indicating the close correlation with the possible high-T polarized state. These emergent phenomena may be qualitatively explained by the co-existence of two low-T polarization components, a scenario that was proposed earlier. One is the component associated with the Mn3+-Mn4+-Mn3+ exchange striction that seems to be tightly clamped by the high-T polarized state, and the other is the component associated with the Gd3+-Mn4+-Gd3+ exchange striction that is free of the clamping. The present findings may offer a different scheme for the electric control of the multiferroicity in RMn2O5.
Effects of growth temperature and metamorphic buffer on electron mobility of InAs film grown on Si substrate by molecular beam epitaxy
Superlubricity enabled dry transfer of non-encapsulated graphene
Transferring high-quality exfoliated graphene flakes onto different substrates while keeping the graphene free of polymer residues is of great importance, but at the same time very challenging. Currently, the only feasible way is the so-called all-dry “pick-and-lift” method, in which a hexagonal boron nitride (hBN) flake is employed to serve as a stamp to pick up graphene from one substrate and to lift it down onto another substrate. The transferred graphene samples, however, are always covered or encapsulated by hBN flakes, which leads to difficulties in further characterizations. Here, we report an improved “pick-and-lift” method, which allows ultra-clean graphene flakes to be transferred onto a variety of substrates without hBN coverage. Basically, by exploiting the superlubricity at the graphene/hBN stack interface, we are able to remove the top-layer hBN stamp by applying a tangential force and expose the underneath graphene.
Inclusions in large diamond single crystals at different temperatures of synthesis
Synthesis and characterization of β-Ga2O3@GaN nanowires
In this work, we prepared the β-Ga2O3@GaN nanowires (NWs) by oxidizing GaN NWs. High-quality hexagonal wurtzite GaN NWs were achieved and the conversion from GaN to β-Ga2O3 was confirmed by x-ray diffraction, Raman spectroscopy and transmission electron microscopy. The effect of the oxidation temperature and time on the oxidation degree of GaN NWs was investigated systematically. The oxidation rate of GaN NWs was estimated at different temperatures.
High material quality growth of AlInAsSb thin films on GaSb substrate by molecular beam epitaxy
Modeling for heterogeneous multi-stage information propagation networks and maximizing information