Surface electromagnetic waves at the interface between dissipative porous nanocomposite and hypercrystal under different temperatures
Publication date: Available online 5 August 2019Source: Physics Letters AAuthor(s): I. FedorinAbstractIn the current paper the properties of surface plasmon polaritons as well as hybrid polarized surface electromagnetic waves at the plane interface of a porous semiconductor nanomaterial and a hypercrystal are studied theoretically and numerically. The nanomaterial, as well as the hypercrystal, is made of n-type doped indium antimonide (n-InSb) semiconductor layers. The losses which inherent to the semiconductor materials are taken into account. To describe the properties of the constituent semiconductor layers the approxim...
Source: Physics Letters A - August 6, 2019 Category: Physics Source Type: research

Thermoelectric performance of monolayer Bi2Te2Se of ultra low lattice thermal conductivity
Publication date: Available online 5 August 2019Source: Physics Letters AAuthor(s): Bin Xu, Liangong Song, Gaohui Peng, Jing Zhang, Shanshan Ma, Yusheng Wang, Yuanxu WangAbstractThe electronic structure and thermoelectric properties of monolayer Bi2Te2Se were studied by density functional theory and semi-classical Boltzmann transport equation. The band gap with TB-mBJ can be improved for monolayer Bi2Te2Se. Monolayer Bi2Te2Se have ultra-low thermal conductivity comparing with other well-known two-dimensional materials. The monolayer Bi2Te2Se can improve electrical conductivities. ZT increases with increasing temperature fo...
Source: Physics Letters A - August 6, 2019 Category: Physics Source Type: research

Phase transition of a second kind in nickel as observed through optical reflection under pressure
Publication date: Available online 5 August 2019Source: Physics Letters AAuthor(s): Moris Sudai, Noaz Nissim, Shalom EliezerAbstractThe magnetic permeability of materials at optical frequencies is usually suggested in the literature to be μ=1. In this case one cannot expect to measure the magnetic second order phase transition at optical frequencies. The main novel idea of this paper is that the magnetic permeability μ is not equal to 1 for optical frequency and a phase transition of magnetism was measured experimentally with an optical frequency. In particular, this work presents the detection of a magnetic second o...
Source: Physics Letters A - August 6, 2019 Category: Physics Source Type: research

Orthorhombic C10: A new superdense carbon allotrope
Publication date: Available online 2 August 2019Source: Physics Letters AAuthor(s): Qun Wei, Wen Tong, Ruike Yang, Haiyan Yan, Bing Wei, Meiguang Zhang, Xinchao Yang, Rui ZhangAbstractBy using unbiased crystal structure searching technique combined with first-principles calculations, a new superdense carbon phase C10 (space group: C222) with a density of 3.55g/cm3 (larger than that of diamond (3.50g/cm3)) is uncovered. The C10 phase has a 10-atom unit cell in the full sp3 bonding network. A systematic theoretical study of the electronic, dynamic, optical, and elastic properties of superdense carbon C10 was carried out. In ...
Source: Physics Letters A - August 3, 2019 Category: Physics Source Type: research

Nitrogen-rich GaN5 and GaN6 as High Energy Density Materials With Modest Synthesis Condition
Publication date: Available online 2 August 2019Source: Physics Letters AAuthor(s): Zhao Liu, Da Li, Shuli Wei, Yan Liu, Fubo Tian, Defang Duan, Tian CuiAbstractHere, the energetic gallium nitrides with the network and zigzag poly-nitrogen configurations at modest pressures have been predicted. The nitrogen-rich Cmc21-GaN5, high-pressure P21/m-GaN5 and C2/c-GaN6 phases can release higher energy of ∼3.27 kJ g−1, 4.12 kJ g−1, 5.71 kJ g−1, respectively, which are close to or even higher than that of the traditional high energy density materials TNT and possess distinguished detonation performance simulat...
Source: Physics Letters A - August 3, 2019 Category: Physics Source Type: research

LiB6Si: An indirect band gap semiconductor
Publication date: Available online 2 August 2019Source: Physics Letters AAuthor(s): Zhikang Yuan, Dongli YuAbstractUsing first-principle calculations, mechanical properties, electronic structure, and Raman spectra of LiB6Si structure were investigated. The band structures calculated by GGA-PBE and HSE06 methods reveal that LiB6Si is an indirect band gap semiconductor. The band gap estimated by HSE06 method is about 2.24 eV, which is in good agreement with that of experimental value 2.27 eV. The calculated tensile stress-strain curves of LiB6Si reveal that [010] direction is the cleavage direction under tensile strains. The...
Source: Physics Letters A - August 3, 2019 Category: Physics Source Type: research

Investigate the z-average mean-square radius of gyration of star-shape polymers using the average number of subchains
Publication date: Available online 2 August 2019Source: Physics Letters AAuthor(s): Yuelan Tian, Hongzan Song, Fang Gu, Libin Bai, Haijun Wang, Xinwu BaAbstractThe general treatment is proposed to investigate the explicit expressions of the average number of subchains with definite monomer sequences on the polymer skeleton, in which the AB+Af type polycondensation is chosen as the classical model of polymerization. The linear homo-polymers and star-shape co-polymers are examined to derive the z-average mean-square radius of gyration, respectively, where the mass of monomers are taken into consideration. Furthermore, the z-...
Source: Physics Letters A - August 3, 2019 Category: Physics Source Type: research

Perspectives on spin hydrodynamics in ferromagnetic materials
This article provides an overview of the theoretical foundations of spin hydrodynamics and their physical interpretation in the context of spin transport. We discuss other proposed applications for spin hydrodynamics as well as our view on challenges and future research directions. (Source: Physics Letters A)
Source: Physics Letters A - August 3, 2019 Category: Physics Source Type: research

Efficiency and power enhancement of solar cells by dark states
Publication date: Available online 2 August 2019Source: Physics Letters AAuthor(s): Sangchul OhAbstractWe study how dark states enhance the efficiency and power of a solar cell as a quantum heat engine. Conventional approaches assume the solar cell is in thermal equilibrium with both hot and cold baths simultaneously. We propose an description that a solar cell is surrounded only by the cold bath and the thermal radiation from the hot bath is described by a pumping term in a master equation. We calculated the current-voltage curve, the power-voltage curve, the efficiency, and the power of the solar cell for different photo...
Source: Physics Letters A - August 3, 2019 Category: Physics Source Type: research

Beam-core evolution equation and space-charge limit
Publication date: Available online 31 July 2019Source: Physics Letters AAuthor(s): Taufik, Ken TakayamaAbstractThe nonlinear beam-core evolution equation approach is proposed as a powerful tool to estimate the acceptable beam current in a given circular accelerator. The approach is justified by the macroparticle simulation over a wide beam current parameter region. Space-charge effects on the beam-core evolution are discussed by Poincaré mapping on the beam-core phase space (σ, dσ/ds). The instability seen in the beam-core evolution is rigorously analyzed as an eigenvalue problem in the coupled linear sy...
Source: Physics Letters A - August 2, 2019 Category: Physics Source Type: research

On the thermophoresis in dense dust structures in neon plasma
Publication date: Available online 30 July 2019Source: Physics Letters AAuthor(s): V.V. Shumova, D.N. Polyakov, E.K. Mataybaeva, L.M. VasilyakAbstractNumerical study of the effect of dust particle concentration on the thermophoretic force acting on a dust particle inside a dust structure in plasma has been carried out. The experimental data on the formation of voids in dust structures formed by 2.55 μm dust particles in a glow dc discharge in neon have been used. The simulation has been performed using the diffusion-drift model with taking into account joule heating of discharge. The dependence of the thermophoretic for...
Source: Physics Letters A - July 31, 2019 Category: Physics Source Type: research

Quantifying information loss on chaotic attractors through recurrence networks
Publication date: Available online 30 July 2019Source: Physics Letters AAuthor(s): K.P. Harikrishnan, R. Misra, G. AmbikaAbstractWe propose an entropy measure for the analysis of chaotic attractors through recurrence networks which are un-weighted and un-directed complex networks constructed from time series of dynamical systems using specific criteria. We show that the proposed measure converges to a constant value with increase in the number of data points on the attractor (or the number of nodes on the network) and the embedding dimension used for the construction of the network, and clearly distinguishes between the re...
Source: Physics Letters A - July 31, 2019 Category: Physics Source Type: research

Editors
Publication date: 22 August 2019Source: Physics Letters A, Volume 383, Issue 24Author(s): (Source: Physics Letters A)
Source: Physics Letters A - July 30, 2019 Category: Physics Source Type: research

Shape-induced anisotropy in epitaxial Fe3O4 nanopillars
Publication date: Available online 24 July 2019Source: Physics Letters AAuthor(s): M. Guan, G. Dong, Z. Hu, B. Peng, Y. He, W.Z. Cui, Z. Zhou, M. LiuAbstractFe3O4 nanopillars with remarkably high uniformity and crystallinity are grown on (100)-oriented magnesium aluminate substrates by pulsed laser deposition with a simple anodic-aluminum-oxide template method. Compared with Fe3O4 full film, the nanopillars exhibit higher in-plane magnetic saturation field and lower out-of-plane saturation field. The angular-dependent ferromagnetic resonance, investigated by electron spin resonance spectroscopy, confirms the shape-induced ...
Source: Physics Letters A - July 25, 2019 Category: Physics Source Type: research

Magnetotransport in a zigzag monolayer MoS2 nanoribbon with ferromagnetic electrodes
Publication date: Available online 24 July 2019Source: Physics Letters AAuthor(s): J.-J. Jin, R.-Y. Yuan, Q.-J. Yang, J.L. Tang, A.G. Du, J. Zheng, Y. GuoAbstractIn this research, using the three-band tight-binding model combined with a non-equilibrium Green's function technique, spin-dependent electron transport was investigated in the quantum structure of zigzag monolayer molybdenum disulfide with ferromagnetic electrodes. It was shown that in parallel configurations, the conductance exhibited a quantized oscillating phenomenon, while in the antiparallel configurations with increasing magnetization, the conductance showe...
Source: Physics Letters A - July 25, 2019 Category: Physics Source Type: research

Spin-independent and spin-dependent re-excitation in CdZnTe studied by pump-probe spectroscopy
Publication date: Available online 24 July 2019Source: Physics Letters AAuthor(s): Lihua Teng, Lijun Mu, Xia WangAbstractTime-resolved pump-probe spectroscopy is used to study the re-excitation processes of spin-balanced and spin-polarized electrons trapped by the defect levels in Cd0.86Zn0.14Te. In CdTe, Cd0.96Zn0.04Te, and Cd0.86Zn0.14Te, the electron trapping time and lifetime decrease with the increasing defect density of states that depends on the Zn composition. The abnormal linearly and circularly polarized pump-probe spectroscopies, respectively, demonstrate the presence of spin-independent and spin-dependent re-ex...
Source: Physics Letters A - July 25, 2019 Category: Physics Source Type: research

Generalized Ablowitz-Ladik equation with a dual Lagrangian structure
This article presents a generalized Ablowitz-Ladik (GAL) equation that can be obtained by means of the least action principle in two different ways. This GAL equation may describe the evolution of a discrete system, in which case it is derived from a Langrangian L which obeys a standard Lagrange equation. But this GAL equation may also describe a continuous system with nonlocal interactions, and in this case it is obtained from a different Lagrangian density L which obeys completely different Euler-Lagrange equations. The Lagrangian density L permits us to obtain variational solutions and Noether's conservation laws. Ander...
Source: Physics Letters A - July 24, 2019 Category: Physics Source Type: research

The influence of random edge defects on the electric and optical properties of phosphorene nanoribbons along zigzag direction
Publication date: Available online 22 July 2019Source: Physics Letters AAuthor(s): Zhe Zhou, Jian Li, Jie-Yun YanAbstractPhosphorene nanoribbons are one-dimensional semiconductors with possible edge states falling within its energy bandgap. We build the connection between the possible configurations of edge defects and the corresponding electric and optical properties in practice systems. The influence of the random defects or roughness at the edges of phosphorene nanoribbons cutting along zigzag direction is investigated quantitatively. Theoretical calculations show that the absorption peak due to the transitions involvin...
Source: Physics Letters A - July 24, 2019 Category: Physics Source Type: research

Principle of Unattainability of absolute zero temperature, the Third Law of Thermodynamics, and projective quantum measurements
Publication date: Available online 22 July 2019Source: Physics Letters AAuthor(s): Tien D. KieuAbstractThe Principle of Unattainability rules out the attainment of absolute zero temperature by any finite physical means, no matter how idealised they could be. Nevertheless, we clarify that the Third Law of Thermodynamics, as defined by Nernst's heat theorem statement, is distinct from the Principle of Unattainability in the sense that the Third Law is mathematically equivalent only to the unattainability of absolute zero temperature by quasi-static adiabatic processes. This, on the one hand, leaves open the possibility of at...
Source: Physics Letters A - July 24, 2019 Category: Physics Source Type: research

A physical perspective on classical cloning
Publication date: Available online 22 July 2019Source: Physics Letters AAuthor(s): Anirudh Reddy, Joseph Samuel, Supurna SinhaAbstractThe celebrated quantum no-cloning theorem states that an arbitrary quantum state cannot be cloned perfectly. This raises questions about cloning of classical states, which have also attracted attention. Here, we present a physical approach to the classical cloning process showing how cloning can be realised using Hamiltonians. After writing down a canonical transformation that clones classical states, we show how this can be implemented by Hamiltonian evolution. We then propose an experiment...
Source: Physics Letters A - July 24, 2019 Category: Physics Source Type: research

Robust entanglement transfer through a disordered qubit ladder
Publication date: Available online 22 July 2019Source: Physics Letters AAuthor(s): Guilherme M.A. Almeida, Andre M.C. Souza, Francisco A.B.F. de Moura, Marcelo L. LyraAbstractWe study an entanglement transfer protocol in a two-leg ladder spin-1/2 chain in the presence of disorder. In the scenario where the on-site energies and intrachain couplings are correlated, following approximately constant proportions along the chain, we set up a scheme for high-fidelity state transfer via a particular subspace wherein effective fluctuations in the parameters ultimately depend on the degree of such correlations, rather on the disorde...
Source: Physics Letters A - July 24, 2019 Category: Physics Source Type: research

Unambiguous determining the Curie point in perovskite manganite with second-order phase transition by scaling method
Publication date: Available online 19 July 2019Source: Physics Letters AAuthor(s): Yunfei Xie, Jiyu Fan, Lisha Xu, Xiyuan Zhang, Ruixing Xu, Yan Zhu, Rujun Tang, Caixia Wang, Chunlan Ma, Li Pi, Yuheng Zhang, Hao YangAbstractThe accurate determination of the Curie temperature (TC) is particularly important in describing the magnetic behavior close to the paramagnetic-ferromagnetic (PM-FM) phase transition. In this paper, we studied the magnetic phase transition and accurately predicted the Curie point of perovskite manganite La0.825Sr0.175MnO3. We find the compound shows a second-order PM-FM transition and has a large magne...
Source: Physics Letters A - July 21, 2019 Category: Physics Source Type: research

High-pressure synthesis, structure and magnetic properties of LaCrO3 ceramics
Publication date: Available online 19 July 2019Source: Physics Letters AAuthor(s): Hai-Shan Xu, Yan-Wei Yang, Rui-Long Wang, Hai-Bo Xiao, Ling-Fang Xu, Shi-Heng Liang, Chang-ping YangAbstractSingle-phase LaCrO3 ceramics was synthesized successfully by the solid state sintering method under high pressure (5 GPa). X-ray diffraction measurements suggest that the high-pressure synthesized sample is well-crystallized, but the cell volume is larger than that of the sample synthesized under ambient pressure, which can be ascribed to the occurrence of Cr2+ converted form part of Cr3+. Such mixed valent state with coexistence of Cr...
Source: Physics Letters A - July 21, 2019 Category: Physics Source Type: research

Ising model with invisible states on scale-free networks
Publication date: Available online 19 July 2019Source: Physics Letters AAuthor(s): Petro Sarkanych, Mariana KrasnytskaAbstractWe consider the Ising model with invisible states on scale-free networks. Our goal is to investigate the interplay between the entropic and topological influence on a phase transition. The former is manifest through the number of invisible states r, while the latter is controlled by the network node-degree distribution decay exponent λ. We show that the phase diagram, in this case, is characterised by two marginal values rc1(λ) and rc2(λ), which separate regions with different c...
Source: Physics Letters A - July 21, 2019 Category: Physics Source Type: research

Spin thermoelectrics
Publication date: Available online 18 July 2019Source: Physics Letters AAuthor(s): Haiming Yu, Weiwei Lin, Jean-Philippe Ansermet (Source: Physics Letters A)
Source: Physics Letters A - July 19, 2019 Category: Physics Source Type: research

Nonlinear excitation and stability analysis of ion-acoustic waves in a magnetized quantum plasma with exchange-correlation effects of degenerate electrons
Publication date: Available online 18 July 2019Source: Physics Letters AAuthor(s): Shahzad Mahmood, Hafeez Ur-Rehman, Sajjad Hussain, Muhammad AdnanAbstractThe nonlinear ion-acoustic wave excitation and its stability analysis are investigated in a magnetized quantum plasma with exchange-correlation and Bohm diffraction effects of degenerate electrons in the model. Using reductive perturbation technique, the Zakharov-Kuznetsov (ZK) equation is derived for two dimensional propagation of ion-acoustic wave in a magnetized quantum plasma. It is found that the phase speed, amplitude and width of the nonlinear ion-acoustic wave s...
Source: Physics Letters A - July 19, 2019 Category: Physics Source Type: research

Structure transition and photoluminescence of CdS/Si nanoheterostructure array on thermal annealing
Publication date: Available online 18 July 2019Source: Physics Letters AAuthor(s): Peng Fei Ji, Yong Li, Yue Li Song, Feng Qun Zhou, Ming Li Tian, Shu Qing YuanAbstractCdS/Si heterojunctions have been prepared through growing CdS nanocrystallites (nc-CdS) on the silicon nanoporous pillar array (Si-NPA) by the chemical bath deposition method. Cadmium nanocrystallites (nc-Cd) have been observed and ascribed to the reducibility of Si-NPA. The reason for the appearance of CdO is indistinct and the related work will be done in the future. The blue, green and red emissions are ascribed to the silicon oxide layer, band gap of nc-...
Source: Physics Letters A - July 19, 2019 Category: Physics Source Type: research

The median-based resolution of the St. Petersburg paradox
Publication date: Available online 17 July 2019Source: Physics Letters AAuthor(s): Takuya Okabe, Momoka Nii, Jin YoshimuraAbstractThe St. Petersburg Paradox contributed to establishing expected utility theory by demonstrating that decision making based on the expectation (expected value, or mean, average) leads to an unreasonable behavior. Although the expected value is commonly used as an optimization criterion in various fields of mathematical sciences, such paradoxical problems as arbitrariness and intransitivity have led many researchers to forsake expected utility theory in search of more useful alternatives. Here we ...
Source: Physics Letters A - July 18, 2019 Category: Physics Source Type: research

Frictional effect on stability of discontinuity interface in tangential velocity of a shallow-water flow
Publication date: Available online 17 July 2019Source: Physics Letters AAuthor(s): Liangbing Jin, Lê Thị Thái, Yasuhide FukumotoAbstractWe examine a frictional effect on the linear stability of an interface of discontinuity in tangential velocity. The fluid is moving with uniform velocity U in a region but is at rest in the other, and the bottom surface is assumed to exert drag force, quadratic in velocity, on the thin fluid layer. In the absence of the drag, the instability of the Kelvin-Helmholtz type is suppressed for U>8c, with c being the propagating speed of the gravity wave. We find by asymptotic a...
Source: Physics Letters A - July 18, 2019 Category: Physics Source Type: research

Detecting nonclassicality of light via Lieb's concavity
Publication date: Available online 17 July 2019Source: Physics Letters AAuthor(s): Shunlong Luo, Yue ZhangAbstractNonclassical light states are important for both conceptual and practical reasons: they are basic ingredients in testing and exploring quantum foundations, and are crucial resources in quantum technologies. Various useful criteria have been developed to detect nonclassicality in the literature, and several meaningful measures of nonclassicality have been introduced and measured experimentally. In this work, by use of a non-Hermitian generalization of the Wigner-Yanase-Dyson skew information and playing with ope...
Source: Physics Letters A - July 18, 2019 Category: Physics Source Type: research

Manipulation of dielectric, ferroelectric and magnetic anomalies in multiferroic, morphotropic phase boundary quenched BiFeO3-0.35PbTiO3 solid solutions
Publication date: Available online 16 July 2019Source: Physics Letters AAuthor(s): Layiq Zia, G. Hassnain Jaffari, Jamil Ur Rahman, Soonil Lee, S. Ismat ShahAbstractThe effect of thermal quenching on physical properties of morphotropic phase boundary BiFeO3-0.35PbTiO3 composition, composed of Pnma, R3c and P4mm phases, has been investigated in detail. We detected and quantified role of quenching through investigation of magnetic, dielectric and ferroelectric anomalies. Quenching significantly i) enhances the tetragonal phase percentage (hence affects domain structure), ii) reduces domain wall clamping with a large increase...
Source: Physics Letters A - July 17, 2019 Category: Physics Source Type: research

A numerical method for fractional Schrödinger equation of Lennard-Jones potential
Publication date: Available online 12 July 2019Source: Physics Letters AAuthor(s): Marwan Al-Raeei, Moustafa Sayem El-DaherAbstractDepending on fractional analysis, we find a numerical algorithm to solve the time-independent fractional Schrödinger equation in case of Lennard-Jones potential in one dimension. We apply the algorithm for multiple values of the fractional parameter of the space-dependent fractional Schrödinger equation and multiple values of the system's energy to find the wave function and the probability in these cases. (Source: Physics Letters A)
Source: Physics Letters A - July 14, 2019 Category: Physics Source Type: research

Hole doped α-MgAgSb as potential low temperature thermoelectric materials
Publication date: Available online 12 July 2019Source: Physics Letters AAuthor(s): Gang Zhou, Ji-wen Xu, Guang-hui RaoAbstractThe electronic structures and thermoelectric transport properties of α-MgAgSb were systematically investigated by using the first principles calculations combined with the Boltzmann transport equations. It is found that the thermoelectric properties of p-type α-MgAgSb are much better than those of n-type one, which originates from the steeper slope of the density of states at the edge of the valence band. By analyzing the density of states and partial charge density, we conclude that p-d...
Source: Physics Letters A - July 14, 2019 Category: Physics Source Type: research

Evolution of cooperation in the spatial public goods game with the third-order reputation evaluation
Publication date: Available online 12 July 2019Source: Physics Letters AAuthor(s): Yang Wenpan, Juan Wang, Chengyi XiaAbstractIn this letter, in order to deeply explore the role of individual reputation in the evolutionary game dynamics, we present a new third-order reputation evaluation model to discuss the evolution of cooperation in the spatial public goods game. In the current model, we should not only consider the strategy (cooperation, C or defection, D) of a focal player, but also take his own reputation and his opponent's reputation status into account. Among them, the individual reputation will be divided into bei...
Source: Physics Letters A - July 14, 2019 Category: Physics Source Type: research

Magnetic transitions in delafossite CuFeO2: A magnetocaloric effect study
Publication date: Available online 12 July 2019Source: Physics Letters AAuthor(s): Lei Zhang, Bernard A. Goodman, DingKang Xiong, Wen DengAbstractCuFeO2 was synthetized by a solid-state reaction and its low temperature magnetic properties investigated using the magnetocaloric effect. Magnetic susceptibility measurements show that there are two magnetic transition temperatures at about 16 and 11 K. Measurement of isothermal magnetization curves for different applied magnetic fields near these temperatures show a reversal in the magnetization trend around 11 K, and Arrott plots indicate they are accompanied by second- and fi...
Source: Physics Letters A - July 14, 2019 Category: Physics Source Type: research

Design of a negative group delay filter via reservoir computing approach: Real-time prediction of chaotic signals
Publication date: Available online 11 July 2019Source: Physics Letters AAuthor(s): Tatjana Pyragiene, Kestutis PyragasAbstractAn optimal arbitrary order filter with negative group delay is proposed for a real-time prediction of complex band-limited signals. The filter consists of a set of second-order linear dissipative oscillators and is determined by a rational transfer function with fixed poles and optimized zeros. The filter design and optimization algorithm is based on a reservoir computing approach. The predictive properties of the filter are demonstrated numerically for two chaotic model systems — the finite-d...
Source: Physics Letters A - July 12, 2019 Category: Physics Source Type: research

Band alignment regulation of HfO2/SiC heterojunctions induced by PEALD with in situ NH3-plasma passivation
Publication date: Available online 11 July 2019Source: Physics Letters AAuthor(s): Dawei Xu, Li Zheng, Xinhong Cheng, Gang Wang, Qian Wang, Wenbo Xin, Peiyi Ye, Lingyan Shen, Yuehui YuAbstractThe efficient passivation of in situ NH3-plasma pre-treatment and its regulation of the band alignment between HfO2 and 4H-SiC have been investigated by XPS. With in situ NH3-plasma passivation by PEALD, a VBO of 0.72 eV and a CBO of 1.54 eV can be obtained across the HfO2/4H-SiC interface. The Si-O bonds components reduction in the passivated interface layers will lead to band bending or band shift at the interface and regulate the b...
Source: Physics Letters A - July 12, 2019 Category: Physics Source Type: research

Experimental study of the effect of propellant asymmetrical distribution on anode current in a Hall effect thruster
Publication date: Available online 11 July 2019Source: Physics Letters AAuthor(s): Minghao Ding, Hong Li, Yongjie Ding, Hui Liu, Daren Yu, Xiaogang WangAbstractThis paper experimentally evaluated the effect of the disruption of the symmetrical distribution of the propellant on the characteristics of the anode current. The change in the asymmetry degree of the propellant distribution is achieved by supplying gas with a dual-cavity gas distributor. The results show that as the asymmetry degree increases, the magnitude of the anode current changes monotonically from a slow growth to a rapid growth, while the peak-to-peak valu...
Source: Physics Letters A - July 12, 2019 Category: Physics Source Type: research

The occurrence of multistability and normal mode splitting in an optomechanical system
Publication date: Available online 11 July 2019Source: Physics Letters AAuthor(s): Kamran UllahAbstractWe provide a theoretical technique to study the occurrence of multistability and normal mode splitting in an optomechanical system driven by a single mode cavity field. For this purpose, we consider the position-dependent mass mechanical resonator (PDMR) which produces the nonlinearity in the system. This shifts the system from monostable to bistable regime and bistable to a multistable regime at different conditions of the nonlinearity. Further, we use the Fourier transform technique to find out the fluctuation in the po...
Source: Physics Letters A - July 12, 2019 Category: Physics Source Type: research

A novel anode attachment mode in argon-helium free-burning arcs at atmospheric pressure
Publication date: Available online 11 July 2019Source: Physics Letters AAuthor(s): Cheng Wang, Qiang Sun, Zelong Zhang, Weidong XiaAbstractAn argon-helium free-burning arc that operates on a graphite anode is investigated. Images of the arc and anode attachment under different arc currents and different helium ratios are exhibited. Experimental results show that both the arc and anode attachment are characterized by demixing. Moreover, an annular dark region surrounding the anode center is observed in the anode attachment region under the conditions of a higher arc current and a higher helium ratio, which is similar to the...
Source: Physics Letters A - July 12, 2019 Category: Physics Source Type: research

Photonic band structure in a two-dimensional hexagonal lattice of equilateral triangles
Publication date: Available online 11 July 2019Source: Physics Letters AAuthor(s): Francis Segovia-Chaves, Herbert Vinck-Posada, Erik Navarro-BarónAbstractIn this paper, the plane wave expansion method is used to calculate the photonic band structure (PBS) for the transverse electric (TE) polarization in a two-dimensional hexagonal lattice composed air holes with cross-sections in the shape of equilateral triangles embedded in a GaAs background. We consider that the dielectric constant of GaAs is dependent on both hydrostatic pressure and temperature. Further, an increase can be observed in the width of the photonic...
Source: Physics Letters A - July 12, 2019 Category: Physics Source Type: research

Dynamics to the universal structure of one-dimensional self-gravitating systems in the quasi-equilibrium state
We present a phenomenological model to describe the universal structure by using a special Langevin equation with a distinctive random noise to self-gravitating systems. Additionally, we unveil a mechanism which decides the radius of the system. (Source: Physics Letters A)
Source: Physics Letters A - July 12, 2019 Category: Physics Source Type: research

The single-polarization filter composed of gold-coated photonic crystal fiber
Publication date: Available online 11 July 2019Source: Physics Letters AAuthor(s): Chao Liu, Liying Wang, Lin Yang, Famei Wang, Chunhong Xu, Jingwei Lv, Guanglai Fu, Xianli Li, Qiang Liu, Haiwei Mu, Tao Sun, Paul K. ChuAbstractA single-polarization filter comprising a gold-coated photonic crystal fiber based on surface plasmon resonance is designed and investigated. The pattern matching and coupled polarization characteristics analyzed by the full-vector finite element method (FEM) and losses at 1,540 nm are achieved to 1,016.01739 dB/cm (x-pol core mode) and 33.81917 dB/cm (y-pol core mode). The crosstalk (CT) value of th...
Source: Physics Letters A - July 12, 2019 Category: Physics Source Type: research

Integral invariants for non-barotropic flows in a four dimensional space time manifold
Publication date: Available online 10 July 2019Source: Physics Letters AAuthor(s): Susan Mathew Panakkal, M.J. VedanAbstractProperties of non-barotropic flows are described using Lie derivatives of differential forms in a Euclidean four dimensional space-time manifold. Vanishing of the Lie derivative implies that the corresponding physical quantity remains invariant along the integral curves of the flow. Integral invariants of non-barotropic perfect and viscous flows are studied using the concepts of relative and absolute invariance of forms. The four dimensional expressions for the rate of change of the generalized circul...
Source: Physics Letters A - July 12, 2019 Category: Physics Source Type: research

Ground states of spin-orbit-coupled Bose Einstein condensates in the presence of external magnetic field
Publication date: Available online 10 July 2019Source: Physics Letters AAuthor(s): Rui-Fang Zhang, Yongping Zhang, Lu LiAbstractTwo different kinds of spin-orbit (SO) coupling are often investigated theoretically and experimentally in atomic Bose-Einstein condensates (BECs), namely, Rashba and Dresselhaus SO couplings. We show that ground states for these two SO-coupled BECs share lots of similarities and it is impossible to distinguish them from the observation of ground states. We find that an Ioffe-Pritchard magnetic field can be utilized as a tool to distinguish them. In the presence of the Ioffe-Pritchard magnetic fie...
Source: Physics Letters A - July 12, 2019 Category: Physics Source Type: research

Statistical description of multiple collisions in the Fermi-Ulam model
Publication date: Available online 10 July 2019Source: Physics Letters AAuthor(s): Diogo Ricardo da Costa, Mario R. Silva, Edson D. Leonel, J.A. Méndez-BermúdezAbstractThe Fermi-Ulam model consists of a point particle colliding elastically between two hards walls, one is considered fixed and the other one oscillates periodically in time. Most investigations on this model are based on a map approach that, although it is extremely efficient from the computational point of view, ignores processes which are relevant for a thorough dynamical description. The map approach considers the so called static wall approxi...
Source: Physics Letters A - July 12, 2019 Category: Physics Source Type: research

Unambiguous discrimination of nonorthogonal entangled quantum states in cavity QED
Publication date: Available online 10 July 2019Source: Physics Letters AAuthor(s): R.J. de Assis, J.S. Sales, N.G. de AlmeidaAbstractIn this work we propose a scheme in the context of superconducting cavities to unambiguously discriminate non-orthogonal quantum field states when one of them is one of the four Bell states. The present work, which generalizes an earlier proposal [1] dealing with non-entangled states, also makes use of a single high Q cavity, a sample of three-level atoms, Ramsey zones and selective detectors, thus consisting of an oversimplification from the experimental view. (Source: Physics Letters A)
Source: Physics Letters A - July 12, 2019 Category: Physics Source Type: research

GPU-based DPSO algorithm for structural optimization of Pt-Co bimetallic nanoparticles
Publication date: Available online 10 July 2019Source: Physics Letters AAuthor(s): Gui-Fang Shao, Jian-Bo Yang, Jun-Fa Zhang, Tun-Dong Liu, Yu-Hua WenAbstractAlloy nanoparticles (NPs) are potential candidates for catalysts in fuel cells applications, and their physical properties are associated with the corresponding stable structures. In this work, a GPU-based discrete particle swarm optimization (DPSO) method is designed to investigate the stable structure of Pt-Co alloy NPs. Register and an optimal block design are used to further increase the acceleration ratio. Comparative experiments on CPU and GPU show that the GPU-...
Source: Physics Letters A - July 12, 2019 Category: Physics Source Type: research

Nonlinear bandgap properties in a nonlocal piezoelectric phononic crystal nanobeam
Publication date: Available online 9 July 2019Source: Physics Letters AAuthor(s): Denghui Qian, Zhiyu Shi, Chengwei Ning, Jianchun WangAbstractApplying nonlocal elasticity theory, von Kármán type nonlinear strain-displacement relation and plane wave expansion (PWE) method to Euler-Bernoulli beam, the calculation method of band structure of a nonlinear nonlocal piezoelectric phononic crystal (PC) nanobeam is proposed and formulized. In order to investigate the properties of wave propagating in the nanobeam in detail, band gaps of first four orders are picked, and the corresponding influence rules of electro-me...
Source: Physics Letters A - July 10, 2019 Category: Physics Source Type: research

Temperature-dependent XAFS study of the local lattice distortion of the CuO2 plane in Sr2CuO3+δ powder sample
Publication date: Available online 9 July 2019Source: Physics Letters AAuthor(s): Haibo Wang, Ying Liu, Zhenlin Luo, Qingqing Liu, Yuanjun Yang, Haoliang Huang, Mengmeng Yang, Changqing Jin, Chen GaoAbstractIn order to study the relationship between local lattice distortion and superconductivity, we performed temperature dependent x-ray absorption fine structure (XAFS) on Sr2CuO3+δ powder sample (single phase with Tc=48 K). The temperature dependent Debye-Waller factor of Cu-O pair appears an anomalous upturn at 90 K and becomes drop around the superconducting transition temperature of ∼50 K. It means that local ...
Source: Physics Letters A - July 10, 2019 Category: Physics Source Type: research