Large linear magnetoresistance in a new Dirac material BaMnBi2
Dirac semimetal is a class of materials that host Dirac fermions as emergent quasi-particles. Dirac cone-type band structure can bring interesting properties such as quantum linear magnetoresistance and large mobility in the materials. In this paper, we report the synthesis of high quality single crystals of BaMnBi2 and investigate the transport properties of the samples. BaMnBi2 is a metal with an antiferromagnetic transition at TN=288 K. The temperature dependence of magnetization displays different behavior from CaMnBi2 and SrMnBi2, which suggests the possible different magnetic structure of BaMnBi2. The Hall data reveals electron-type carriers and a mobility μ(5 K)=1500 cm2/V·s. Angle-dependent magnetoresistance reveals the quasi-two-dimensional (2D) Fermi surface in BaMnBi2. A crossover from semiclassical MR～H2 dependence in low field to MR～H dependence in high field, which is attributed to the quantum limit of Dirac fermions, has been observed in magnetoresistance. Our results indicate the existence of Dirac fermions in BaMnBi2.
An application of a combined gradient system to stabilize a mechanical system
Consensus for second-order multi-agent systems with position sampled data
Nonlinear radiation response of n-doped indium antimonide and indium arsenide in intense terahertz field
The nonlinear radiation responses of two different n-doped bulk semiconductors: indium antimonide (InSb) and indium arsenide (InAs) in an intense terahertz (THz) field are studied by using the method of ensemble Monte Carlo (EMC) at room temperature. The results show that the radiations of two materials generate about 2-THz periodic regular spectrum distributions under a high field of 100 kV/cm at 1-THz center frequency. The center frequencies are enhanced to about 7 THz in InSb, and only 5 THz in InAs, respectively. The electron valley occupancy and the percentage of new electrons excited by impact ionization are also calculated. We find that the band nonparabolicity and impact ionization promote the generation of nonlinear high frequency radiation, while intervalley scattering has the opposite effect. Moreover, the impact ionization dominates in InSb, while impact ionization and intervalley scattering work together in InAs. These characteristics have potential applications in up-convension of THz wave and THz nonlinear frequency multiplication field.
Terahertz-dependent identification of simulated hole shapes in oil—gas reservoirs
The bound state solution for the Morse potential with a localized mass profile
Binding energy of the donor impurities in GaAs-Ga1-xAlxAs quantum well wires with Morse potential in the presence of electric and magnetic fields
A novel scheme of hybrid entanglement swapping and teleportation using cavity QED in the small and large detuning regimes and quasi-Bell state measurement method
Controlled remote preparation of an arbitrary four-qubit cluster-type state
Parameter allocation of parallel array bistable stochastic resonance and its application in communication systems
Demodulation of acoustic telemetry binary phase shift keying signal based on high-order Duffing system
A novel color image encryption algorithm based on genetic recombination and the four-dimensional memristive hyperchaotic system
Quantitative measurement of hydroxyl radical (OH) concentration in premixed flat flame by combining laser-induced fluorescence and direct absorption spectroscopy
Calculations of the dynamic dipole polarizabilities for the Li+ ion
The B-spline configuration-interaction method is applied into the investigations of dynamic dipole polarizabilities for the four lowest triplet states (23S, 33S, 23P, and 33P) of the Li+ ion. The accurate energies for the triplet states of n3S, n3P, and n3D, the dipole oscillator strengths for 23S(33S)→n3P, 23P(33P)→n3S, and 23P(33P)→n3D transitions, with the main quantum number n up to 10 are tabulated for references. The dynamic dipole polarizabilities for the four triplet states under a wide range of photon energy are also listed, which provide input data for analyzing the Stark shift of Li+ ion. Furthermore, the tune-out wavelengths in the range from 100 nm to 1.2 μm for the four triplet states, and the magic wavelengths in the range from 100 nm to 600 nm for the 23S→33S, 23S→23P, and 23S→33P transitions are determined accurately for the experimental design of the Li+ ion.
An ab initio investigation of vibrational, thermodynamic, and optical properties of Sc2AlC MAX compound
Low-lying electronic states of CuN calculated by MRCI method
Effect of chloride introduction on the optical properties in Eu3+-doped fluorozirconate glasses
Analysis of the blackbody-radiation shift in an ytterbium optical lattice clock
We accurately evaluate the blackbody-radiation shift in a 171Yb optical lattice clock by utilizing temperature measurement and numerical simulation. In this work. three main radiation sources are considered for the blackbody-radiation shift, including the heated atomic oven, the warm vacuum chamber, and the room-temperature vacuum windows. The temperatures on the outer surface of the vacuum chamber are measured during the clock operation period by utilizing seven calibrated temperature sensors. Then we infer the temperature distribution inside the vacuum chamber by numerical simulation according to the measured temperatures. Furthermore, we simulate the temperature variation around the cold atoms while the environmental temperature is fluctuating. Finally, we obtain that the total blackbody-radiation shift is -1.289(7) Hz with an uncertainty of 1.25×10-17 for our 171Yb optical lattice clock. The presented method is quite suitable for accurately evaluating the blackbody-radiation shift of the optical lattice clock in the case of lacking the sensors inside the vacuum chamber.
Absorption of laser radiation in ultracold plasma
Ultra-thin two-dimensional transmissive anisotropic metasurfaces for polarization filter and beam steering application
Two-dimensional atom localization induced by a squeezed vacuum
Photon bunching and anti-bunching with two dipole-coupled atoms in an optical cavity
Quantum metrology with two-mode squeezed thermal state: Parity detection and phase sensitivity
Spontaneous emission from a microwave-driven four-level atom in an anisotropic photonic crystal
Effects of annealing time on the structure, morphology and stress of gold-chromium bilayer film
Acoustic focusing through two layer annuluses in air
Pseudopotential multi-relaxation-time lattice Boltzmann model for cavitation bubble collapse with high density ratio
Pattern formation in superdiffusion Oregonator model
Pattern formations in an Oregonator model with superdiffusion are studied in two-dimensional (2D) numerical simulations. Stability analyses are performed by applying Fourier and Laplace transforms to the space fractional reaction-diffusion systems. Antispiral, stable turing patterns, and travelling patterns are observed by changing the diffusion index of the activator. Analyses of Floquet multipliers show that the limit cycle solution loses stability at the wave number of the primitive vector of the travelling hexagonal pattern. We also observed a transition between antispiral and spiral by changing the diffusion index of the inhibitor.
An acoustic Maxwell's fish-eye lens based on gradient-index metamaterials
Bio-inspired optimization algorithms for optical parameter extraction of dielectric materials: A comparative study
Electronic transport of Lorentz plasma with collision and magnetic field effects
K—P—Burgers equation in negative ion-rich relativistic dusty plasma including the effect of kinematic viscosity
Effect of Bohm quantum potential in the propagation of ion-acoustic waves in degenerate plasmas
Influence of number and depth of magnetic mirror on Alfvénic gap eigenmode
LIF diagnostics of hydroxyl radical in a methanol containing atmospheric-pressure plasma jet
In this paper, a pulsed-dc CH3OH/Ar plasma jet generated at atmospheric pressure is studied by laser-induced fluorescence (LIF) and optical emission spectroscopy (OES). A gas-liquid bubbler system is proposed to introduce the methanol vapor into the argon gas, and the CH3OH/Ar volume ratio is kept constant at about 0.1%. Discharge occurs in a 6-mm needle-to-ring gap in an atmospheric-pressure CH3OH/Ar mixture. The space-resolved distributions of OH LIF inside and outside the nozzle exhibit distinctly different behaviors. And, different production mechanisms of OH radicals in the needle-to-ring discharge gap and afterglow of plasma jet are discussed. Besides, the optical emission lines of carbonaceous species, such as CH, CN, and C2 radicals, are identified in the CH3OH/Ar plasma jet. Finally, the influences of operating parameters (applied voltage magnitude, pulse frequency, pulsewidth) on the OH radical density are also presented and analyzed.
Influence of dielectric materials on uniformity of large-area capacitively coupled plasmas for N2/Ar discharges
The effect of the dielectric ring on the plasma radial uniformity is numerically investigated in the practical 450-mm capacitively coupled plasma reactor by a two-dimensional self-consistent fluid model. The simulations were performed for N2/Ar discharges at the pressure of 300 Pa, and the frequency of 13.56 MHz. In the practical plasma treatment process, the wafer is always surrounded by a dielectric ring, which is less studied. In this paper, the plasma characteristics are systematically investigated by changing the properties of the dielectric ring, i.e., the relative permittivity, the thickness and the length. The results indicate that the plasma parameters strongly depend on the properties of the dielectric ring. As the ratio of the thickness to the relative permittivity of the dielectric ring increases, the electric field at the wafer edge becomes weaker due to the stronger surface charging effect. This gives rise to the lower N2+ ion density, flux and N atom density at the wafer edge. Thus the homogeneous plasma density is obtained by selecting optimal dielectric ring relative permittivity and thickness. In addition, we also find that the length of the dielectric ring should be as short as possible to avoid the discontinuity of the dielectric materials, and thus obtain the large area uniform plasma.
Static and dynamic properties of polymer brush with topological ring structures: Molecular dynamic simulation
By defining a topological constraint value (rn), the static and dynamic properties of a polymer brush composed of moderate or short chains with different topological ring structures are studied using molecular dynamics simulation, and a comparison with those of linear polymer brush is also made. For the center-of-mass height of the ring polymer brush scaled by chain length h～Nν, there is no significant difference of exponent from that of a linear brush in the small topological constraint regime. However, as the topological constraint becomes stronger, one obtains a smaller exponent. It is found that there exists a master scaling power law of the total stretching energy scaled by chain length N for moderate chain length regime, Fene～Nρν, for ring polymer brushes, but with a larger exponent ν than 5/6, indicating an influence of topological constraint to the dynamic properties of the system. A topological invariant of free energy scaled by <c>5/4 is found.
Self-compliance multilevel storage characteristic in HfO2-based device
In this paper, the self-compliance bipolar resistive switching characteristic of an HfO2-based memory device with Ag/HfO2/Au structure for multilevel storage is investigated. By applying a positive voltage, the dual-step set processes corresponding to three stable resistance states are observed in the device. The multilevel switching characteristics can still be observed after 48 hours. In addition, the resistance values of all the three states show negligible degradation over 104 s, which may be useful for the applications in nonvolatile multilevel storage.
Tensile properties and microstructure of 2024 aluminum alloy subjected to the high magnetic field and external stress
Dynamic behaviors of water contained in calcium—silicate—hydrate gel at different temperatures studied by quasi-elastic neutron scattering spectroscopy
Radial transport dynamics studies of SMBI with a newly developed TPSMBI code
Effects of Si surficial structure on transport properties of La2/3Sr1/3MnO3 films
Thick c-BN films deposited by radio frequency magnetron sputtering in argon/nitrogen gas mixture with additional hydrogen gas
The excellent physical and chemical properties of cubic boron nitride (c-BN) film make it a promising candidate for various industry applications. However, the c-BN film thickness restricts its practical applications in many cases. Thus, it is indispensable to develop an economic, simple and environment-friend way to synthesize high-quality thick, stable c-BN films. High-cubic-content BN films are prepared on silicon (100) substrates by radio frequency (RF) magnetron sputtering from an h-BN target at low substrate temperature. Adhesions of the c-BN films are greatly improved by adding hydrogen to the argon/nitrogen gas mixture, allowing the deposition of a film up to 5-μm thick. The compositions and the microstructure morphologies of the c-BN films grown at different substrate temperatures are systematically investigated with respect to the ratio of H2 gas content to total working gas. In addition, a primary mechanism for the deposition of thick c-BN film is proposed.
Optical absorption enhancement in slanted silicon nanocone hole arrays for solar photovoltaics
HfO2-based ferroelectric modulator of terahertz waves with graphene metamaterial
Tunable modulations of terahertz waves in a graphene/ferroelectric-layer/silicon hybrid structure are demonstrated at low bias voltages. The modulation is due to the creation/elimination of an extra barrier in Si layer in response to the polarization in the ferroelectric Si:HfO2 layer. Considering the good compatibility of HfO2 with the Si-based semiconductor process, the highly tunable characteristics of the graphene metamaterial device under ferroelectric effect open up new avenues for graphene-based high performance integrated active photonic devices compatible with the silicon technology.
Electronic structures and edge effects of Ga2S2 nanoribbons
Observation of trapped light induced by Dwarf Dirac-cone in out-of-plane condition for photonic crystals
New ordered MAX phase Mo2TiAlC2: Elastic and electronic properties from first-principles
First-principles studies of effects of interstitial boron and carbon on the structural, elastic, and electronic properties of Ni solution and Ni3Al intermetallics
Time-dependent evolution process of Sb2Te3 from nanoplates to nanorods and their Raman scattering properties
Modified model of gate leakage currents in AlGaN/GaN HEMTs
The spin Hall effect in single-crystalline gold thin films
The spin Hall effect has been investigated in 10-nm-thick epitaxial Au (001) single crystal films via H-pattern devices, whose minimum characteristic dimension is about 40 nm. By improving the film quality and optimizing the in-plane geometry parameters of the devices, we explicitly extract the spin Hall effect contribution from the ballistic and bypass contribution which were previously reported to be dominating the non-local voltage. Furthermore, we calculate a lower limit of the spin Hall angle of 0.08 at room temperature. Our results indicate that the giant spin Hall effect in Au thin films is dominated not by the interior defects scattering, but by the surface scattering. Besides, our results also provide an additional experimental method to determine the magnitude of spin Hall angle unambiguously.
First-principles hybrid functional study of the electronic structure and charge carrier mobility in perovskite CH3NH3SnI3
Design and experimental verification of a dual-band metamaterial filter
Resistive switching characteristic and uniformity of low-power HfOx-based resistive random access memory with the BN insertion layer
In this letter, the Ta/HfOx/BN/TiN resistive switching devices are fabricated and they exhibit low power consumption and high uniformity each. The reset current is reduced for the HfOx/BN bilayer device compared with that for the Ta/HfOx/TiN structure. Furthermore, the reset current decreases with increasing BN thickness. The HfOx layer is a dominating switching layer, while the low-permittivity and high-resistivity BN layer acts as a barrier of electrons injection into TiN electrode. The current conduction mechanism of low resistance state in the HfOx/BN bilayer device is space-charge-limited current (SCLC), while it is Ohmic conduction in the HfOx device.
Transport properties of the topological Kondo insulator SmB6 under the irradiation of light
In this paper, we study transport properties of the X point in the Brillouin zone of the topological Kondo insulator SmB6 under the application of a circularly polarized light. The transport properties at high-frequency regime and low-frequency regime as a function of the ratio (κ) of the Dresselhaus-like and Rashba-like spin-orbit parameter are studied based on the Floquet theory and Boltzmann equation respectively. The sign of Hall conductivity at high-frequency regime can be reversed by the ratio κ and the amplitude of the light. The amplitude of the current can be enhanced by the ratio κ. Our findings provide a way to control the transport properties of the Dirac materials at low-frequency regime.
Topological phase transition in a ladder of the dimerized Kitaev superconductor chains
Quantitative analysis of ammonium salts in coking industrial liquid waste treatment process based on Raman spectroscopy
Theory of specific heat of vortex liquid of high Tc superconductors
Controlled synthesis of ferromagnetic MnSex particles
Negative dependence of surface magnetocrystalline anisotropy energy on film thickness in Co33Fe67 alloy
Effect of exchange interaction in ferromagnetic superlattices: A Monte Carlo study
Structural and magnetic properties of turmeric functionalized CoFe2O4 nanocomposite powder
Emergent ferroelectricity in disordered tri-color multilayer structure comprised of ferromagnetic manganites
Multiferroic materials, showing the coexistence and coupling of ferroelectric and magnetic orders, are of great technological and fundamental importance. However, the limitation of single phase multiferroics with robust magnetization and polarization hinders the magnetoelectric effect from being applied practically. Magnetic frustration, which can induce ferroelectricity, gives rise to multiferroic behavior. In this paper, we attempt to construct an artificial magnetically frustrated structure comprised of manganites to induce ferroelectricity. A disordered stacking of manganites is expected to result in frustration at interfaces. We report here that a tri-color multilayer structure comprised of non-ferroelectric La0.9Ca0.1MnO3(A)/Pr0.85Ca0.15MnO3(B)/Pr0.85Sr0.15MnO3(C) layers with the disordered arrangement of ABC-ACB-CAB-CBA-BAC-BCA is prepared to form magnetoelectric multiferroics. The multilayer film exhibits evidence of ferroelectricity at room temperature, thus presenting a candidate for multiferroics.
Optoelectronic and thermoelectric properties of Zintl YLi3X2(X=Sb, Bi) compounds through modified Becke—Johnson potential
Transient grating study of the intermolecular dynamics of liquid nitrobenzene
Effects of multiple interruptions with trimethylindium-treatment in the InGaN/GaN quantum well on green light emitting diodes
Polaron effect on the optical rectification in spherical quantum dots with electric field
Theoretical investigations of half-metallic ferromagnetism in new Half—Heusler YCrSb and YMnSb alloys using first-principle calculations
Proper In deposition amount for on-demand epitaxy of InAs/GaAs single quantum dots
Atomic-layer-deposited Al2O3 and HfO2 on InAlAs: A comparative study of interfacial and electrical characteristics
Electric-field-dependent charge delocalization from dopant atoms in silicon junctionless nanowire transistor
We study electric-field-dependent charge delocalization from dopant atoms in a silicon junctionless nanowire transistor by low-temperature electron transport measurement. The Arrhenius plot of the temperature-dependent conductance demonstrates the transport behaviors of variable-range hopping (below 30 K) and nearest-neighbor hopping (above 30 K). The activation energy for the charge delocalization gradually decreases due to the confinement potential of the conduction channel decreasing from the threshold voltage to the flatband voltage. With the increase of the source-drain bias, the activation energy increases in a temperature range from 30 K to 100 K at a fixed gate voltage, but decreases above the temperature of 100 K.
Phase transition of solid bismuth under high pressure
Influence of secondary treatment with CO2 laser irradiation for mitigation site on fused silica surface
Particles inside electrolytes with ion-specific interactions, their effective charge distributions and effective interactions
In this work, we explore the statistical physics of colloidal particles that interact with electrolytes via ion-specific interactions. Firstly we study particles interacting weakly with electrolyte using linear response theory. We find that the mean potential around a particle is linearly determined by the effective charge distribution of the particle, which depends both on the bare charge distribution and on ion-specific interactions. We also discuss the effective interaction between two such particles and show that, in the far field regime, it is bilinear in the effective charge distributions of two particles. We subsequently generalize the above results to the more complicated case where particles interact strongly with the electrolyte. Our results indicate that in order to understand the statistical physics of non-dilute electrolytes, both ion-specific interactions and ionic correlations have to be addressed in a single unified and consistent framework.
Hydrodynamics of passing-over motion during binary droplet collision in shear flow
Mode analysis and design of 0.3-THz Clinotron
Physical modeling of direct current and radio frequency characteristics for InP-based InAlAs/InGaAs HEMTs
Direct current (DC) and radio frequency (RF) performances of InP-based high electron mobility transistors (HEMTs) are investigated by Sentaurus TCAD. The physical models including hydrodynamic transport model, Shockley-Read-Hall recombination, Auger recombination, radiative recombination, density gradient model and high field-dependent mobility are used to characterize the devices. The simulated results and measured results about DC and RF performances are compared, showing that they are well matched. However, the slight differences in channel current and pinch-off voltage may be accounted for by the surface defects resulting from oxidized InAlAs material in the gate-recess region. Moreover, the simulated frequency characteristics can be extrapolated beyond the test equipment limitation of 40 GHz, which gives a more accurate maximum oscillation frequency (fmax) of 385 GHz.
Characteristics of cylindrical surrounding-gate GaAsxSb1-x/InyGa1-yAs heterojunction tunneling field-effect transistors
A two-dimensional analytical modeling for channel potential and threshold voltage of short channel triple material symmetrical gate Stack (TMGS) DG-MOSFET
Photoresponse and trap characteristics of transparent AZO-gated AlGaN/GaN HEMT
Surface treatment on polyethylenimine interlayer to improve inverted OLED performance
Optical nuclear spin polarization in quantum dots
Hyperfine interaction between electron spin and randomly oriented nuclear spins is a key issue of electron coherence for quantum information/computation. We propose an efficient way to establish high polarization of nuclear spins and reduce the intrinsic nuclear spin fluctuations. Here, we polarize the nuclear spins in semiconductor quantum dot (QD) by the coherent population trapping (CPT) and the electric dipole spin resonance (EDSR) induced by optical fields and ac electric fields. By tuning the optical fields, we can obtain a powerful cooling background based on CPT for nuclear spin polarization. The EDSR can enhance the spin flip-flop rate which may increase the cooling efficiency. With the help of CPT and EDSR, an enhancement of 1300 times of the electron coherence time can be obtained after a 10-ns preparation time.
Ultra-compact terahertz switch with graphene ring resonators
Elemental x-ray imaging using Zernike phase contrast
Device simulation of lead-free CH3NH3SnI3 perovskite solar cells with high efficiency
Pedestrian choice behavior analysis and simulation of vertical walking facilities in transfer station
A new cellular automata model of traffic flow with negative exponential weighted look-ahead potential
Asymmetric and symmetric meta-correlations in financial markets
In financial markets, the relation between fluctuations of stock prices and trading behaviors is complex. It is intriguing to quantify this kind of meta-correlation between market fluctuations and the synchronous behaviors. We refine the theoretical index leverage model proposed by Reigneron et al., to exactly quantify the meta-correlation under various levels of price fluctuations [Reigneron P A, Allez R and Bouchaud J P 2011 Physica A 390 3026]. The characteristics of meta-correlations in times of market losses, are found to be significantly different in Chinese and American financial markets. In addition, unlike the asymmetric results at the daily scale, the correlation behaviors are found to be symmetric at the high-frequency scale.
Subtle role of latency for information diffusion in online social networks
Comparision between Ga- and N-polarity InGaN solar cells with gradient-In-composition intrinsic layers