Spin transport in antiferromagnetic insulators
The evolution of cooperation in public good game with deposit
The emergence of cooperation still remains a fundamental conundrum in the social and behavior sciences. We introduce a new mechanism, deposit mechanism, into theoretical model to explore how this mechanism promotes cooperation in a well-mixed population. Firstly, we extend the common binary-strategy combination of cooperation and defection in public good game by adding a third strategy, namely, deposit cooperation. The players with deposit cooperation strategy pay a deposit in advance to obtain the benefits of public good at a lower contributions compared with the players with cooperation strategy, when the provision of public good is successful. Then, we explore the evolution of cooperation in the public good game with deposit by means of the replicator dynamics. Theoretical computations and stimulations show that the deposit mechanism can promote cooperation in a well-mixed population, and the numbers of equilibrium point are determined by variables of public good game. On the one hand, when the coexistence of cooperators and defectors is the stable equilibrium point in the evolutionary system, increasing the threshold of public good and adopting the weak altruism way for share benefits can enhance the level of cooperation in the population. On the other hand, if the coexistence of deposit cooperators and defectors is the stable equilibrium point, it is effective to promote the deposit cooperation by lowering the values of discount and deposit, and raising the threshold of public good.
The upper bound function of nonadiabatic dynamics in parametric driving quantum systems
On a biseparability criterion of bipartite qudit state
Dissipative generation for steady-state entanglement of two transmons in circuit QED
Temperature effects on atmospheric continuous-variable quantum key distribution
Tunable coupling between Xmon qubit and coplanar waveguide resonator
Realization of a flexible and tunable coupling scheme among qubits is critical for scalable quantum information processing. Here, we design and characterize a tunable coupling element based on Josephson junction, which can be adapted to an all-to-all connected circuit architecture where multiple Xmon qubits couple to a common coplanar waveguide resonator. The coupling strength is experimentally verified to be adjustable from 0 MHz to about 40 MHz, and the qubit lifetime can still be up to 12 μs in the presence of the coupling element.
Efficient solver for time-dependent Schrödinger equation with interaction between atoms and strong laser field
We present a parallel numerical method of simulating the interaction of atoms with a strong laser field by solving the time-depending Schrödinger equation (TDSE) in spherical coordinates. This method is realized by combining constructing block diagonal matrices through using the real space product formula (RSPF) with splitting out diagonal sub-matrices for short iterative Lanczos (SIL) propagator. The numerical implementation of the solver guarantees efficient parallel computing for the simulation of real physical problems such as high harmonic generation (HHG) in these interaction systems.
Ellipticity-dependent ionization yield for noble atoms
The photoionization in the frame of the Ammosov-Delone-Krainov theory has been theoretically examined for noble gases, argon, krypton, and xenon, in an elliptically polarized laser field. We consider the intermediate range of the Keldysh parameter, γ~1, and analyze the influence of shifted ionization potential and temporal profile to eliminate disagreement between theoretical and experimental findings. By including these effects in the ionization rates, we solve rate equations in order to determine an expression for the ionization yield. The use of modified ionization potential shows that the ionization yields will actually decrease below the values predicted by original (uncorrected) formulas. This paper will discuss the causes of this discrepancy.
Controlling Rydberg excitation process with shaped intense ultrashort laser pulses
Synthesis and surface plasmon resonance of Au-ZnO Janus nanostructures
Metal-semiconductor Janus nanostructures with asymmetry and directionality have recently aroused significant interest, both in fundamental light-matter interactions mechanism and in technological applications. Here we report the synthesis of different Au-ZnO Janus nanostructures via a facile one-pot colloid method. The growth mechanism is revealed by a series of designed synthesis experiments. The light absorption properties are determined by both the decrease of dipole oscillations of the free electrons and the plasmon-induced hot-electron transfer. Moreover, the finite-difference time-domain (FDTD) simulation method is used to elucidate the electric field distributions of these Janus nanostructures.
Surface plasmon polaritons generated magneto-optical Kerr reversal in nanograting
Controlling the phase of light in magnetoplasmonic structures is receiving increasing attention because of its already shown capability in ultrasensitive and label-free molecular-level detection. Magneto-optical Kerr reversal has been achieved and well explained in nanodisks by using the phase of localized plasmons. In this paper, we report that the Kerr reversal can also be produced by surface plasmon polaritons independently. We experimentally confirm this in Co and Ag/Co/Ag metal nanogratings, and can give a qualitative explanation that it is the charge accumulation at the interface between the grating surface and air that acts as the electromagnetic restoring force to contribute necessary additional phase for Kerr reversal. Our finding can enrich the means of designing and fabricating magneto-optical-based biochemical sensors.
Energetics and diffusion of point defects in Au/Ag metals:A molecular dynamics study
Quasi-classical trajectory study of H+LiH (v=0, 1, 2, j=0)→Li+H2 reaction on a new global potential energy surface
Interference effect of photoionization of hydrogen atoms by ultra-short and ultra-fast high-frequency chirped pulses
Optical design of common-aperture multispectral and polarization optical imaging system with wide field of view
Optimized dithering technique in frequency domain for high-quality three-dimensional depth data acquisition
Phase retrieval algorithm for optical information security
Mask-based denoising scheme for ghost imaging
Single-shot phase-shifting digital holography with a photon-sieve-filtering telescope
Evolution of quantum states via Weyl expansion in dissipative channel
Zinc-oxide nanoparticle-based saturable absorber deposited by simple evaporation technique for Q-switched fiber laser
Pulse generation of erbium-doped fiber laser based on liquid-exfoliated FePS3
As a preferable material in the field of photo-detection and catalysis, the characteristics of FePS3 in broad wavelength range have been proven by many experimental studies. However, FePS3 has not been used as a saturable absorber (SA) in fiber lasers yet. We propose and demonstrate the generation of a single wavelength and dual-wavelength based on an Er-doped fiber laser (EDFL) at 1.5 μm by using an innovative FePS3 saturable absorber for the first time. The result shows that a stable passively Q-switched pulse can be generated, which demonstrates that the new two-dimensional (2D) material FePS3 served as SA provides a valid method to realize passively Q-switched laser. In addition, we achieve the output of the dual-wavelength pulse by properly rotating the polarization controller. To the best of our knowledge, the dual-wavelength pulse EDFL could be applied in biomedicine, spectroscopy, and sensing research.
The 2-μm to 6-μm mid-infrared supercontinuum generation in cascaded ZBLAN and As2Se3 step-index fibers
Fiber-based mid-infrared (MIR) supercontinuum (SC) sources benefit from their spectral brightness and spatial coherence that are needed for many applications, such as spectroscopy and metrology. In this paper, an SC spanning from 2 μm to 6 μm is demonstrated in cascaded ZrF4-BaF2-LaF3-AlF3-NaF (ZBLAN) and As2Se3 step-index fibers. The pump source is a ZBLAN fiber-based MIR SC laser with abundant high-peak-power soliton pulses between 3000 nm and 4200 nm. By concatenating the ZBLAN fiber and the As2Se3 fiber, efficient cascading red-shifts are obtained in the normal dispersion region of the As2Se3 fiber. The spectral behavior of cascaded SC generation shows that the long-wavelength proportion of MIR SC generated in the ZBLAN fiber plays a critical role for further spectral extension in the As2Se3 fiber.
Multi-wavelength continuous-wave Nd:YVO4 self-Raman laser under in-band pumping
Non-crossover sub-Doppler DAVLL in selective reflection scheme
Vertical profile of aerosol extinction based on the measurement of O4 of multi-elevation angles with MAX-DOAS
Non-Stokes drag coefficient in single-particle electrophoresis:New insights on a classical problem Hot!
We measured the intrinsic electrophoretic drag coefficient of a single charged particle by optically trapping the particle and applying an AC electric field, and found it to be markedly different from that of the Stokes drag. The drag coefficient, along with the measured electrical force, yield a mobility-zeta potential relation that agrees with the literature. By using the measured mobility as input, numerical calculations based on the Poisson-Nernst-Planck equations, coupled to the Navier-Stokes equation, reveal an intriguing microscopic electroosmotic flow near the particle surface, with a well-defined transition between an inner flow field and an outer flow field in the vicinity of electric double layer's outer boundary. This distinctive interface delineates the surface that gives the correct drag coefficient and the effective electric charge. The consistency between experiments and theoretical predictions provides new insights into the classic electrophoresis problem, and can shed light on new applications of electrophoresis to investigate biological nanoparticles.
Opto propeller effect on Micro-Rotors with different handedness
Novel transit-time oscillator (TTO) combining advantages of radial-line and axial TTO
Damage characteristics of laser plasma shock wave on rear surface of fused silica glass
Nucleation and growth of helium bubble at (110) twist grain boundaries in tungsten studied by molecular dynamics
Migration of He atoms and growth of He bubbles in high angle twist grain boundaries (HAGBs) in tungsten (W) are investigated by atomic simulation method. The energy and free volume (FV) of grain boundary (GB) are affected by the density and structure of dislocation patterns in GB. The migration energy of the He atom between the neighboring trapping sites depends on free volume along the migration path at grain boundary. The region of grain boundary around the He bubble forms an ordered crystal structure when He bubble grows at certain grain boundaries. The He atoms aggregate on the grain boundary plane to form a plate-shape configuration. Furthermore, high grain boundary energy (GBE) results in a large volume of He bubble. Thus, the nucleation and growth of He bubbles in twist grain boundaries depend on the energy of grain boundary, the dislocation patterns and the free volume related migration path on the grain boundary plane.
Crystal structure and magnetic properties of disordered alloy ErGa3- xMnx
Impeding anion exchange to improve composition stability of CsPbX3 (X=Cl, Br) nanocrystals through facilely fabricated Cs4PbX6 shell
Inorganic lead halide perovskite nanocrystals (NCs) with superior photoelectric properties are expected to have excellent performance in many fields. However, the anion exchange changes their features and is unfavorable for their applications in many fields. Hence, impeding anion exchange is important for improving the composition stability of inorganic lead halide perovskite NCs. Herein, CsPbX3 (X=Cl, Br) NCs are coated with Cs4PbX6 shell to impede anion exchange and reduce anion mobility. The Cs4PbX6 shell is facily fabricated on CsPbX3 NCs through high temperature injection method. Anion exchange experiments demonstrate that the Cs4PbX6 shell completely encapsulates CsPbX3 NCs and greatly improves the composition stability of CsPbX3 NCs. Moreover, our work also sheds light on the potential design approaches of various heterostructures to expand the application of CsPbM3 (M=Cl, Br, I) NCs.
Electronic structure of single-crystalline graphene grown on Cu/Ni (111) alloy film
Graphene with a Dirac cone-like electronic structure has been extensively studied because of its novel transport properties and potential application for future electronic devices. For epitaxially grown graphene, the process conditions and the microstructures are strongly dependent on various substrate materials with different lattice constants and interface energies. Utilizing angle-resolved photoemission spectroscopy, here we report an investigation of the electronic structure of single-crystalline graphene grown on Cu/Ni (111) alloy film by chemical vapor deposition. With a relatively low growth temperature, graphene on Cu/Ni (111) exhibits a Dirac cone-like dispersion comparable to that of graphene grown on Cu (111). The linear dispersions forming Dirac cone are as wide as 2 eV, with the Fermi velocity of approximately 1.1×106 m/s. Dirac cone opens a gap of approximately 152 meV at the binding energy of approximately 304 meV. Our findings would promote the study of engineering of graphene on different substrate materials.
Electronic and optical properties of GaN-MoS2 heterostructure from first-principles calculations
Structural, mechanical, and electronic properties of 25 kinds of Ⅲ-V binary monolayers:A computational study with first-principles calculation
Effects of surface charges on phonon properties and thermal conductivity in GaN nanofilms
Surface charges can modify the elastic modulus of nanostructure, leading to the change of the phonon and thermal properties in semiconductor nanostructure. In this work, the influence of surface charges on the phonon properties and phonon thermal conductivity of GaN nanofilm are quantitatively investigated. In the framework of continuum mechanics, the modified elastic modulus can be derived for the nanofilm with surface charges. The elastic model is presented to analyze the phonon properties such as the phonon dispersion relation, phonon group velocity, density of states of phonons in nanofilm with the surface charges. The phonon thermal conductivity of nanofilm can be obtained by considering surface charges. The simulation results demonstrate that surface charges can significantly change the phonon properties and thermal conductivity in a GaN nanofilm. Positive surface charges reduce the phonon energy and phonon group velocity but increase the density of states of phonons. The surface charges can change the size and temperature dependence of phonon thermal conductivity of GaN nanofilm. Based on these theoretical results, one can adjust the phonon properties and temperature/size dependent thermal conductivity in GaN nanofilm by changing the surface charges.
Measurement scheme to detect α relaxation time of glass-forming liquid
Organic field-effect transistor floating-gate memory using polysilicon as charge trapping layer
Electronic structure from equivalent differential equations of Hartree-Fock equations
SymTopo:An automatic tool for calculating topological properties of nonmagnetic crystalline materials Hot!
Topological materials have novel properties both in their bulk and boundaries, thereby attracting a wide interest in the theoretical and experimental communities. The recent development of the topological quantum chemistry and symmetry-based indicator theory in this field has significantly simplified the procedure for determining the topological properties of nonmagnetic crystalline materials. Accordingly, a large number of new topological materials have been found by scanning large crystal databases. This study provides details on the algorithm used in the Catalogue of Topological Electronic Materials. Moreover, based on the algorithm, we develop an automatic package named SymTopo, which calculates the symmetry representations of any given nonmagnetic crystalline material and predicts its topological properties. This package may facilitate the discovery of more topological materials in the future.
Effect of strain on exciton dynamics in monolayer WS2
Energy band alignment at Cu2O/ZnO heterojunctions characterized by in situ x-ray photoelectron spectroscopy
Effects of active layer thickness on performance and stability of dual-active-layer amorphous InGaZnO thin-film transistors
Dual-active-layer (DAL) amorphous InGaZnO (IGZO) thin-film transistors (TFTs) are fabricated at low temperature without post-annealing. A bottom low-resistance (low-R) IGZO layer and a top high-resistance (high-R) IGZO layer constitute the DAL homojunction with smooth and high-quality interface by in situ modulation of oxygen composition. The performance of the DAL TFT is significantly improved when compared to that of a single-active-layer TFT. A detailed investigation was carried out regarding the effects of the thickness of both layers on the electrical properties and gate bias stress stabilities. It is found that the low-R layer improves the mobility, ON/OFF ratio, threshold voltage and hysteresis voltage by passivating the defects and providing a smooth interface. The high-R IGZO layer has a great impact on the hysteresis, which changes from clockwise to counterclockwise. The best TFT shows a mobility of 5.41 cm2/V…, a sub-threshold swing of 95.0 mV/dec, an ON/OFF ratio of 6.70×107, a threshold voltage of 0.24 V, and a hysteresis voltage of 0.13 V. The value of threshold voltage shifts under positive gate bias stress decreases when increasing the thickness of both layers.
Effects of oxygen vacancy concentration and temperature on memristive behavior of SrRuO3/Nb:SrTiO3 junctions
Metal/semiconductor memristive heterostructures have potential applications in nonvolatile memory and computing devices. To enhance the performance of the memristive devices, it requires a comprehensive engineering to the metal/semiconductor interfaces. Here in this paper, we discuss the effects of oxygen vacancies and temperature on the memristive behaviors of perovskite-oxide Schottky junctions, each consisting of SrRuO3 thin films epitaxially grown on Nb:SrTiO3 substrates. The oxygen partial pressure and laser fluence are controlled during the film growth to tune the oxygen defects in SrRuO3 films, and the Schottky barrier height can be controlled by both the temperature and oxygen vacancies. The resistive switching measurements demonstrate that the largest resistance switching ratio can be obtained by controlling oxygen vacancy concentration at lower temperature. It suggests that reducing Schottky barrier height can enhance the resistive switching performance of the SrRuO3/Nb:SrTiO3 heterostructures. This work can conduce to the development of high-performance metal-oxide/semiconductor memristive devices.
Quaternary antiferromagnetic Ba2BiFeS5 with isolated FeS4 tetrahedra
We report the detailed physical properties of quaternary compound Ba2BiFeS5 with the key structural ingredient of isolated FeS4 tetrahedra. Magnetization and heat capacity measurements clearly indicate that Ba2BiFeS5 has a paramagnetic to antiferromagnetic transition at about 30 K. The calculated magnetic entropy above ordering temperature is much smaller than theoretical value for high-spin Fe3+ ion with S=5/2, implying the possible short-range antiferromagnetic fluctuation in Ba2BiFeS5.
Model of output characteristics of giant magnetoresistance (GMR) multilayer sensor
Thermal stability, crystallization, and magnetic properties of FeNiBCuNb alloys
Spectral properties of Pr:CNGG crystals grown by micro-pulling-down method
Pr3+-doped calcium niobium gallium garnet (Pr:CNGG) single crystals with different Pr3+concentrations are successfully grown by the micro-pulling-down (μ-PD) method. The crystal structure, room-temperature absorption spectra, and fluorescence spectra of Pr:CNGG crystals are measured and discussed. The fluorescence results indicate their large dependence on the doping concentration. The fluorescence lifetime of the 1D2 energy level is also determined. The results indicate that Pr:CNGG crystal could be a potential solid-state laser gain medium.
Monolithic semi-polar (1101) InGaN/GaN near white light-emitting diodes on micro-striped Si (100) substrate
The epitaxial growth of novel GaN-based light-emitting diode (LED) on Si (100) substrate has proved challenging. Here in this work, we investigate a monolithic phosphor-free semi-polar InGaN/GaN near white light-emitting diode, which is formed on a micro-striped Si (100) substrate by metal organic chemical vapor deposition. By controlling the size of micro-stripe, InGaN/GaN multiple quantum wells (MQWs) with different well widths are grown on semi-polar (1101) planes. Besides, indium-rich quantum dots are observed in InGaN wells by transmission electron microscopy, which is caused by indium phase separation. Due to the different widths of MQWs and indium phase separation, the indium content changes from the center to the side of the micro-stripe. Various indium content provides the wideband emission. This unique property allows the semipolar InGaN/GaN MQWs to emit wideband light, leading to the near white light emission.
Non-perturbative multiphoton excitation studies in an excitonic coupled quantum well system using high-intensity THz laser fields
Analysis of elliptical thermal cloak based on entropy generation and entransy dissipation approach
Thin-film growth behavior of non-planar vanadium oxide phthalocyanine
The thin film properties of organic semiconductors are very important to the device performance. Herein, non-planar vanadyl phthalocyanine (VOPc) thin films grown on rigid substrates of indium tin oxide, silicon dioxide, and flexible substrate of kapton by organic molecular beam deposition under vacuum conditions are systematically studied via atomic force microscopy and x-ray diffraction. The results clearly reveal that the morphology and grain size are strongly dependent on the substrate temperature during the process of film deposition. Meanwhile, the VOPc films with the structure of phase I or phase Ⅱ can be modulated via in situ annealing and post-annealing temperature. Furthermore, the crystalline structure and molecular orientation of vapor-deposited VOPc can be controlled using molecular template layer 3, 4, 9, 10-perylene-tetracarboxylic dianhydride (PTCDA), the VOPc film of which exhibits the phase I structure. The deep understanding of growth mechanism of non-planar VOPc film provides valuable information for controlling structure-property relationship and accelerates the application in electronic and optoelectronic devices.
Structural model of substitutional sulfur in diamond
Study on the nitridation of β-Ga2O3 films
Single-crystal GaN layers have been obtained by nitriding β-Ga2O3 films in NH3 atmosphere. The effect of the temperature and time on the nitridation and conversion of Ga2O3 films have been investigated. The nitridation process results in lots of holes in the surface of films. The higher nitridation temperature and longer time can promote the nitridation and improve the crystal quality of GaN films. The converted GaN porous films show the single-crystal structures and low-stress, which can be used as templates for the epitaxial growth of high-quality GaN.
Structural response of aluminum core-shell particles in detonation environment
Improving robustness of GGNMOS with P-base layer for electrostatic discharge protection in 0.5-μm BCD process
Negative gate bias stress effects on conduction and low frequency noise characteristics in p-type poly-Si thin-film transistors
Rectifying characteristics and solar-blind photoresponse in β-Ga2O3/ZnO heterojunctions
Effects of bismuth on structural and dielectric properties of cobalt-cadmium spinel ferrites fabricated via micro-emulsion route
New design of ferroelectric solar cell combined with luminescent solar concentrator
Exploring alkylthiol additives in PBDB-T:ITIC blended active layers for solar cell applications
Bulk heterojunction, non-fullerene PBDB-T:ITIC blend polymer solar cells have been fabricated. The active layers consisting of PBDB-T as a donor and ITIC as an acceptor are optimized using a series of alkylthiol additives (1,3-propanedithiol, 1,4-butanedithiol, and 1,8-octanedithiol). It is found that the donor and acceptor are phase separated with different crystalline domains. The additives effectively re-organize the morphology and extend the molecule ordering in lamellar structure with increased correlation length in ITIC domain, benefiting the generation and dissociation of exciton and reducing charge recombination. A substantial improvement in power conversion efficiency of the devices from 8.13% to 9.44% is observed. This study shows that the application of alkylthiol additives is a simple and effective approach to improve the device performance in solar cells based on polymer/non-fullerene blend system.