**Tuning the optical properties of Fe-Au core-shell nanoparticles with spherical and spheroidal nanostructures**

Publication date: Available online 10 May 2019Source: Physics Letters AAuthor(s): Pradeep Bhatia, S.S. Verma, M.M. SinhaAbstractPresent research interest is to highlight on the manufacturing of core-shell nanoparticles because of core activity with unique properties and surface modification by a shell in the diverse fields (e.g. optoelectronic, catalysis and magneto-optics). In addition, the combined optical properties of magnetic-plasmonic core-shell NPs make them ideal candidates for many applications in biomedical fields. The influence of Fe-core and Au-shell for the formation of the core-shell viz. spherical and sphero...

**Source: **Physics Letters A - May 12, 2019 **Category: **Physics **Source Type: **research

**Editors**

Publication date: 16 June 2019Source: Physics Letters A, Volume 383, Issue 17Author(s): (Source: Physics Letters A)

**Source: **Physics Letters A - May 12, 2019 **Category: **Physics **Source Type: **research

**Dual solutions and stability analysis of flow and heat transfer of Casson fluid over a stretching sheet**

Publication date: Available online 30 April 2019Source: Physics Letters AAuthor(s): M. Hamid, M. Usman, Z.H. Khan, R. Ahmad, W. WangAbstractThe aim of the current study is to find out the dual solutions of the two-dimensional magnetohydrodynamic (MHD) flow of Casson fluid and heat transfer over the stretching sheet. The focus of the study is to examine the linear thermal radiation effects on dual solutions for both the steady and unsteady flow of Casson fluid over the stretching sheet under the influence of uniform magnetic field. The governing equations are formed as system of partial differential equations (PDEs). Using ...

**Source: **Physics Letters A - May 10, 2019 **Category: **Physics **Source Type: **research

**Spin thermoelectricity in dualhydrogenated zigzag silicene nanoribbons with surface adsorptions**

Publication date: Available online 9 May 2019Source: Physics Letters AAuthor(s): Yushen Liu, Xiaoshuang Chen, Xifeng YangAbstractThe buckled structure of silicene provides a feasible pathway to influence its electric and magnetic properties via surface adsorptions. Here, we investigate the magnetic and spin thermoelectric transport properties of dual-hydrogenated zigzag silicene nanoribbons (ZSiNRs) without/with the hydrogen adsorption. The band gaps for two spin channels in ZSiNRs under the hydrogen adsorption are shifted near the Fermi level, leading to the appearance of spin Seebeck effect. Using a temperature differenc...

**Source: **Physics Letters A - May 10, 2019 **Category: **Physics **Source Type: **research

**Growth curve based label propagation algorithm for community detection**

Publication date: Available online 8 May 2019Source: Physics Letters AAuthor(s): Xue LiAbstractHow to better and faster identify the community structure is a hot issue in complex networks. During the past decades, various attempts have been made to solve this issue. Amongst them, without doubt, label propagation algorithm (LPA) is one of the most satisfying answers, especially for large-scale networks. However, it has one major flaw that when the community structure is not clear enough, a monster community tends to form. To address this issue, we set a growth curve for communities, gradually increasing from a low capacity ...

**Source: **Physics Letters A - May 10, 2019 **Category: **Physics **Source Type: **research

**Spatiotemporal dynamics of the polarisation state of laser radiation performed by lens-axicon combinations**

Publication date: Available online 8 May 2019Source: Physics Letters AAuthor(s): S.N. Khonina, S.G. Volotovsky, A.V. Ustinov, A.P. PorfirevAbstractSpatiotemporal dynamics of the polarisation state of laser radiation performed by lens-axicon combinations were investigated theoretically and numerically in the paraxial regime. We demonstrate that in this case, while the static polarisation state does not change, various features are observed in the temporal dynamics, including spiral trajectories of the field components, transformation of the polarisation state and the “disappearance” of the light field at some ti...

**Source: **Physics Letters A - May 10, 2019 **Category: **Physics **Source Type: **research

**Dynamical precession of spin in the two-dimensional spin-orbit coupled systems**

Publication date: Available online 8 May 2019Source: Physics Letters AAuthor(s): Tsung-Wei Chen, Zhi-Yang Huang, Dah-Wei ChiouAbstractWe investigate the spin dynamics in the two-dimensional spin-orbit coupled system subject to an in-plane (x-y plane) constant electric field, which is assumed to be turned on at the moment t=0. The equation of spin precession in linear response to the switch-on of the electric field is derived in terms of Heisenberg's equation by the perturbation method up to the first order of the electric field. The dissipative effect, which is responsible for bringing the dynamical response to an asymptot...

**Source: **Physics Letters A - May 10, 2019 **Category: **Physics **Source Type: **research

**Direct calculation of time varying Aharonov-Bohm effect**

Publication date: Available online 8 May 2019Source: Physics Letters AAuthor(s): S. Rai Choudhury, Shobhit MahajanAbstractThe Aharonov-Bohm effect (ABE) for steady magnetic fields is a well known phenomenon. However, if the current in the infinite solenoid that creates the magnetic field is time-dependent, that is in the presence of both magnetic and electric fields, there is no agreement whether the effect would be present. In this note, we try to investigate time varying ABE by a direct calculation in a set-up with a weak time dependent magnetic field. We find that the electric field arising out of the time-varying magne...

**Source: **Physics Letters A - May 10, 2019 **Category: **Physics **Source Type: **research

**Kalman filter-based phase estimation of continuous-variable quantum key distribution without sending local oscillator**

Publication date: Available online 7 May 2019Source: Physics Letters AAuthor(s): Yu Su, Ying Guo, Duan HuangAbstractPhase estimation is one of the crucial procedures in continuous-variable quantum key distribution without sending local oscillator (LLO-CVQKD), aiming at compensating the phase drift in post-processing. To decrease the phase noise caused by the phase drift and measurement error, we propose Kalman filter-based phase noise estimation of LLO-CVQKD, which involves the measurements and filtering through exploiting the small amplitude reference pulses, achieving the accurate phase noise estimation. Simulation resul...

**Source: **Physics Letters A - May 9, 2019 **Category: **Physics **Source Type: **research

**Non-Markovianity in the presence of multiple thermal environments via collision model**

Publication date: Available online 7 May 2019Source: Physics Letters AAuthor(s): Qi Zhang, Zhong-Xiao Man, Yun-Jie XiaAbstractBy means of the collision model, we study the non-Markovianity of an open quantum system S being coupled to M thermal reservoirs. In our model, each reservoir is modeled as a chain of ancillas whose intracollisions account for the occurrence of non-Markovian dynamics. We show that by incorporating M reservoir ancillas into the system, the non-Markovian dynamics of S can be embedded in the extended system that experiences a completely Markovian dynamics. The number M of involved reservoirs can thus b...

**Source: **Physics Letters A - May 9, 2019 **Category: **Physics **Source Type: **research

**Simulating the Klein tunneling of pseudospin-one Maxwell particles with trapped ions**

Publication date: Available online 7 May 2019Source: Physics Letters AAuthor(s): Peng He, Xin Shen, Dan-Wei Zhang, Shi-Liang ZhuAbstractWe propose an experimental scheme to simulate and observe the Klein tunneling of relativistic Maxwell particles with trapped ions. We explore the scattering dynamics of the pseudospin-one Maxwell particles and demonstrate that the scattered state should be a superposition of a reflection state, a localization state, and a transmission state. The probabilities of these states can be analytically obtained by the approach of Landau-Zener transition. We further show that the Maxwell Hamiltonia...

**Source: **Physics Letters A - May 9, 2019 **Category: **Physics **Source Type: **research

**Activation mechanisms of silver toward CO oxidation by tungsten carbide substrate: A density functional theory study**

Publication date: Available online 7 May 2019Source: Physics Letters AAuthor(s): Yuling Zhao, Xilin Zhang, Zongxian YangAbstractThe development of efficient catalysts for low temperature CO oxidation is important to the application of fuel cells. In this work, we report that the Ag monolayer on WC (0001) surface (AgML/WC) could effectively catalyze CO oxidation through the L-H mechanism (CO + O2 → OOCO → CO2 + O). The most sluggish reaction step is suggested to be CO + O → CO2 with a barrier of 0.48 eV, which is 1.21 eV lower than the barrier of O2 dissociation. The electronic structure and d-band center ana...

**Source: **Physics Letters A - May 9, 2019 **Category: **Physics **Source Type: **research

**Thermal transport properties in monolayer GeS**

Publication date: Available online 6 May 2019Source: Physics Letters AAuthor(s): Yongqing Wang, Xiuxian Yang, Yuanfang ShangAbstractUtilizing the first-principle techniques combined with the Boltzmann transport equation, we investigate the thermal transport properties of monolayer GeS. The calculated lattice thermal conductivity κL is fairly low, e.g., 11.76 (12.53) Wm−1K−1 at 300 K, along the x (y) axis, which is much lower than the values for phosphorene, monolayer MoS2, graphene, etc. Our analysis reveals that the low lattice thermal conductivity is resulted from the strong three-phonon scattering proc...

**Source: **Physics Letters A - May 7, 2019 **Category: **Physics **Source Type: **research

**High-pressure phases and pressure-induced phase transition of MoN6 and ReN6**

We report two new nitrogen-rich Transition metal nitrides, MoN6 and ReN6, by crystal structure searching technique. Under high pressure, MoN6 will undergo phase transition (from R-3m to Pm-3 phase) at 54 GPa, and ReN6 always keep the R-3m phase in the pressure range from 50 to 100 GPa. There are benzene-like six-membered “N6” rings with nitrogen single bonds in the R-3m phase structures, indicating that MoN6 and ReN6 are expected to be the high-energy-density materials. (Source: Physics Letters A)

**Source: **Physics Letters A - May 7, 2019 **Category: **Physics **Source Type: **research

**Transparent quantum graphs**

Publication date: Available online 3 May 2019Source: Physics Letters AAuthor(s): J.R. Yusupov, K.K. Sabirov, M. Ehrhardt, D.U. MatrasulovAbstractWe consider quantum graphs with transparent branching points. To design such networks, the concept of transparent boundary conditions is applied to the derivation of the vertex boundary conditions for the linear Schrödinger equation on metric graphs. This allows to derive simple constraints, which make usual Kirchhoff-type boundary conditions at the vertex equivalent to the transparent ones. The approach is applied to quantum star and tree graphs. However, extension to more c...

**Source: **Physics Letters A - May 4, 2019 **Category: **Physics **Source Type: **research

**Acoustic absorbers at low frequency based on split-tube metamaterials**

Publication date: Available online 3 May 2019Source: Physics Letters AAuthor(s): Peng Wu, Qianjin Mu, Xiaoxiao Wu, Li Wang, Xin Li, Yuqing Zhou, Shuxia Wang, Yingzhou Huang, Weijia WenAbstractThe remarkable properties of acoustic metamaterials have attracted massive researches and applications, especially on low-frequency sound absorptions. Currently, most of the acoustic metamaterial absorbers employ resonances in plastic cavities, and their structural strengths are important in many circumstances, especially in harsh environment. However, studies of metamaterials including this point are very scarce. Here, we propose an ...

**Source: **Physics Letters A - May 4, 2019 **Category: **Physics **Source Type: **research

**Thickness-dependent magnetic order and phase-transition dynamics in epitaxial Fe-rich FeRh thin films**

Publication date: Available online 3 May 2019Source: Physics Letters AAuthor(s): C.Q. Yu, H. Li, Y.M. Luo, L.Y. Zhu, Z.H. Qian, T.J. ZhouAbstractThe control of magnetic order and phase-transition dynamics by various means is a key towards low-power spintronics. Here, we report a control on magnetic order and phase-transition dynamics by tuning film thickness in epitaxial FeRh films. Reduction of film thicknesses from 200 nm to 5 nm results in an anti-ferromagnetic to ferromagnetic phase change, accompanied by a 0.55% lattice expansion for c-axis. The phase-transition dynamics is highly dependent on the film thickness, and ...

**Source: **Physics Letters A - May 4, 2019 **Category: **Physics **Source Type: **research

**Classical random walk with memory versus quantum walk on a one-dimensional infinite chain**

Publication date: Available online 3 May 2019Source: Physics Letters AAuthor(s): Jingfeng Wu, Peng Xu, Xuanmin ZhuAbstractQuantum walk is a very useful tool for building quantum algorithms due to the faster spreading of probability distributions as compared to a classical random walk. Comparing the spreading of the probability distributions of a quantum walk with that of a mnemonic classical random walk on a one-dimensional infinite chain, we find that the classical random walk could have a faster spreading than that of the quantum walk conditioned on a finite number of walking steps. Quantum walk surpasses classical rando...

**Source: **Physics Letters A - May 4, 2019 **Category: **Physics **Source Type: **research

**Pauli semigroups and unistochastic quantum channels**

Publication date: Available online 3 May 2019Source: Physics Letters AAuthor(s): Zbigniew Puchała, Łukasz Rudnicki, Karol ŻyczkowskiAbstractWe adopt the perspective of similarity equivalence, in gate set tomography called the gauge, to analyze various properties of quantum operations belonging to a semigroup, Φ=eLt, and therefore given through the Lindblad operator. We first observe that the non unital part of the channel decouples from the time evolution. Focusing on unital operations we restrict our attention to the single-qubit case, showing that the semigroup embedded inside the tetrahedron of Pauli channels is ...

**Source: **Physics Letters A - May 4, 2019 **Category: **Physics **Source Type: **research

**Relaxation dynamics in a stochastic bosonic Josephson junction**

Publication date: Available online 2 May 2019Source: Physics Letters AAuthor(s): Dionisis Stefanatos, Emmanuel PaspalakisAbstractWe consider a bosonic Josephson junction in the Bose-Hubbard two-mode approximation where some of the parameters are corrupted by physically meaningful noise processes and study the corresponding relaxation dynamics towards its equilibrium state. We show with numerical simulations that this model can essentially capture all the important features observed in a recent experiment regarding the relaxation dynamics in one-dimensional bosonic Josephson junctions, namely the damped oscillations of the ...

**Source: **Physics Letters A - May 4, 2019 **Category: **Physics **Source Type: **research

**Size effect on electric-double-layer capacitances of conducting structures**

Publication date: Available online 2 May 2019Source: Physics Letters AAuthor(s): Fuqian YangAbstractThe charge storage in an electrical double-layer capacitor is dependent on the accumulation of ions on the interface between electrolyte and conducting material and the spatial distribution of ions in electrolyte. In this work, we study the effect of local curvature on the concentration of ions on the interface between electrolyte and electrode from the framework of thermodynamics and incorporate the concentration of ions on the interface in the analysis of the spatial distribution of ions for symmetric binary electrolytes. ...

**Source: **Physics Letters A - May 4, 2019 **Category: **Physics **Source Type: **research

**The influence of coupling between chains on the conductivity of atomic carbon chains**

Publication date: Available online 2 May 2019Source: Physics Letters AAuthor(s): Zhewen Liang, Xiaodong Xu, Yingjie Jiang, Weiqi Li, Qiang Wang, Guiling Zhang, Wei Quan Tian, Yongyuan JiangAbstractThis work presents a theoretical investigation on the electronic properties of double atomic carbon chains bridging graphene electrodes with density functional theory in combination with non-equilibrium Green's function. The influence of strain on the conductance of atomic carbon chains is significant. However, the coupling effect between adjacent chains dominates the intrinsic transport of double atomic carbon chains. For the co...

**Source: **Physics Letters A - May 4, 2019 **Category: **Physics **Source Type: **research

**Thomson 4/3 problem leads to nonlocal continuous charges with Poincaré radial stresses and zero electromagnetic inertia**

Publication date: Available online 2 May 2019Source: Physics Letters AAuthor(s): I.E. BulyzhenkovAbstractInertia-free electricity in Maxwell’s equations is consistent with the elementary radial charge. The internal Poincaré stresses stabilize an extended electric charge and participate in zeroing its integral four-momentum. The global overlap of extended particles reinterprets classical physics in nondual terms of elementary material fields without areas of empty space. Measurements in macroscopic experiments can be explained by purely field carriers of electric energy. New probes beyond quantum nonlocality co...

**Source: **Physics Letters A - May 4, 2019 **Category: **Physics **Source Type: **research

**Electronic transport on graphene armchair-edge nanoribbons with Fermi velocity and potential barriers**

Publication date: Available online 30 April 2019Source: Physics Letters AAuthor(s): A.C.S. Nascimento, R.P.A. Lima, M.L. Lyra, J.R.F. LimaAbstractThe transport properties of Dirac fermions through armchair-edge graphene nanoribbons (AGNRs) with a single and double rectangular Fermi velocity vF and electrostatic potential U barriers is investigated. We employ a transfer matrix method (TMM) to compute the transmission coefficient of the full set of propagating mode which is used to obtain the conductance and Fano factor spectra for both metallic and semiconducting nanoribbons. We show that a reduced Fermi velocity within the...

**Source: **Physics Letters A - May 1, 2019 **Category: **Physics **Source Type: **research

**Dual solutions and stability analysis of flow and heat transfer of Casson fluid over the stretching sheet**

Publication date: Available online 30 April 2019Source: Physics Letters AAuthor(s): M. Hamid, M. Usman, Z.H. Khan, R. Ahmad, W. WangAbstractThe aim of the current study is to find out the dual solutions of the two-dimensional magnetohydrodynamic (MHD) flow of Casson fluid and heat transfer over the stretching sheet. The focus of the study is to examine the linear thermal radiation effects on dual solutions for both the steady and unsteady flow of Casson fluid over the stretching sheet under the influence of uniform magnetic field. The governing equations are formed as system of partial differential equations (PDEs). Using ...

**Source: **Physics Letters A - May 1, 2019 **Category: **Physics **Source Type: **research

**Editors**

Publication date: 6 June 2019Source: Physics Letters A, Volume 383, Issue 16Author(s): (Source: Physics Letters A)

**Source: **Physics Letters A - May 1, 2019 **Category: **Physics **Source Type: **research

**Dynamical switching and memory via incoherent pump assisted optical bistability**

Publication date: Available online 29 April 2019Source: Physics Letters AAuthor(s): Ya-Nan Li, Yu-Yuan Chen, Ren-Gang Wan, Hong-Wei YanAbstractWe analyze the dynamical behavior of all-optical switching and memory based on tunable optical bistability in a three-level Λ-type atomic system driven by a probe field circulating in an optical ring cavity, a coherent coupling field and an incoherent pump field outside cavity. Owing to the incoherent pump process, the absorption and Kerr nonlinearity near the atomic resonance change dramatically as a result of varied population distribution and atomic coherence, and then the...

**Source: **Physics Letters A - May 1, 2019 **Category: **Physics **Source Type: **research

**Electronic structures and magnetic properties of CrSiTe3 single-layer nanoribbons**

In this study, we systematically investigate the stability, electronic structures and magnetic properties of CrSiTe3 single-layer nanoribbons with different edge configurations and ribbon widths using first-principles calculations. The results show that the edge energies (less than 0.4 eV/Å) for all studied CrSiTe3 nanoribbons are much lower than that of graphene and many transition-metal dichalcogenide nanoribbons, indicating their stability and easy formation. Compared to the CrSiTe3 monolayer with ferromagnetic semiconductor characterictics, some of CrSiTe3 nanoribbons (N-SiCr-ZNRs, N-Te-ZNRs, N-TeCr-ANRs and N-Te...

**Source: **Physics Letters A - May 1, 2019 **Category: **Physics **Source Type: **research

**Coupling analysis of screwing motion of double-walled carbon nanotubes**

Publication date: Available online 30 April 2019Source: Physics Letters AAuthor(s): Liang Chen, Wu-Gui Jiang, Hang Zou, Xi-Qiao Feng, Qing-Hua Qin, Xin LiAbstractAs the inner tube is excited from a rotation frequency at a separation distance, the inner tube will generate a reciprocating screwing motion. In this work, this coupling effect is investigated theoretically. The van der Waals force between two carbon nanotubes is expressed in a simple form of Fourier series so that the coupled nonlinear differential equations can be quickly solved. The proposed approach is thousands of times faster than the traditional method, wh...

**Source: **Physics Letters A - May 1, 2019 **Category: **Physics **Source Type: **research

**Nuclear probes of an out-of-equilibrium plasma at the highest compression**

We report the highest compression reached in laboratory plasmas using eight laser beams, E≈laser12 kJ, τlaser=2 ns in third harmonic on a CD2 target at the ShenGuang-II Upgrade (SGII-Up) facility in Shanghai, China. We estimate the deuterium density ρD=2.0±0.9 kg/cm3, and the average kinetic energy of the plasma ions less than 1 keV. The highest reached areal density ΛρD=4.8±1.5 g/cm2 was obtained from the measured ratio of the sequential ternary fusion reactions (dd→t+p and t+d→α+n) and the two body reaction fusions (dd→3He+n). At such high densities, sequential ...

**Source: **Physics Letters A - May 1, 2019 **Category: **Physics **Source Type: **research

**Novel electric field effects on Landau levels in multi-Weyl semimetals**

Publication date: Available online 30 April 2019Source: Physics Letters AAuthor(s): Amit GuptaAbstractMulti-Weyl semimetals (WSMs) have an anisotropic non-linear dispersion along a 2-D plane and a linear dispersion in an orthogonal direction. They have topological charge ‘n' and are created when two or multiple Weyl points or nodes with nonzero net monopole charge are brought together onto a high-symmetry point. We study the perturbation corrections up to second order of such multi-WSMs in crossed electric (E) and magnetic (B) fields in the low electric field approximation. As a result, the first order correction lif...

**Source: **Physics Letters A - May 1, 2019 **Category: **Physics **Source Type: **research

**Linear and nonlinear excitations in warm dense matter**

Publication date: Available online 30 April 2019Source: Physics Letters AAuthor(s): M. Akbari-Moghanjoughi, M. MohammadnejadAbstractSmall and large amplitude linear and nonlinear ion acoustic and Langmuir waves are investigated for plasma with the generalized equation of state (EoS). This EoS covers a wide range of energy-density conditions from dilute classical regime up to the relativistically degenerate matter. Investigation shows that the linear dispersion and localized excitations of ion acoustic waves are significantly affected by the plasma parameters. It is also found that the criterion for ordinary soliton existen...

**Source: **Physics Letters A - May 1, 2019 **Category: **Physics **Source Type: **research

**Effect of permanent magnet configuration on discharge characteristics in cylindrical Hall thrusters**

Publication date: Available online 26 April 2019Source: Physics Letters AAuthor(s): Shengtao Liang, Hui Liu, Daren YuAbstractMagnetic field design is important in cylindrical Hall thrusters and using permanent magnets to generate magnetic field is very promising in the future. In two typical permanent magnet configurations (i.e., ring and cylindrical configurations) of cylindrical Hall thrusters, discharge characteristics are compared in this paper through the experiments and simulations. The study shows that the cylindrical configuration can bring about higher thruster performance in the same working condition. The reason...

**Source: **Physics Letters A - April 28, 2019 **Category: **Physics **Source Type: **research

**Origin of the hardness in the monolayer nanographene**

Publication date: Available online 26 April 2019Source: Physics Letters AAuthor(s): Yasin Göktürk YıldızAbstractIn this paper, we investigated the lattice distorsion displacement effects (LDDE) on magnetizations versus temperature in a monolayer nanographene (MLNG) by using effective field theory developed by Kaneyoshi. To obtain the LDDE, we used the twinning angle (Θ) of the zigzag edge of the MLNG and obtain the M-T curves for Θ=100-1800 with 10 steps. We find that MLNG has a minimum Curie temperature (TCmin=2.738) for a certain critical twinning angle (ΘCTA=1300) of the zigzag edge of the ...

**Source: **Physics Letters A - April 28, 2019 **Category: **Physics **Source Type: **research

**A comparative study of local quantum Fisher information and local quantum uncertainty in Heisenberg XY model**

Publication date: Available online 26 April 2019Source: Physics Letters AAuthor(s): A. Slaoui, L. Bakmou, M. Daoud, R. Ahl LaamaraAbstractRecently, it has been shown that the quantum Fisher information via local observables and via local measurements (i.e., local quantum Fisher information (LQFI)) is a central concept in quantum estimation and quantum metrology and captures the quantumness of correlations in multi-component quantum system (Kim et al. (2018) [28]). This new discord-like measure is very similar to the quantum correlations measure called local quantum uncertainty (LQU). In the present study, we have revealed ...

**Source: **Physics Letters A - April 28, 2019 **Category: **Physics **Source Type: **research

**Electronic structures of twist-stacked 1T-TaS2 bilayers**

Publication date: Available online 26 April 2019Source: Physics Letters AAuthor(s): Yunting Li, Huaping Xiao, Pan Zhou, Juexian CaoAbstractBy using first-principles calculations, we investigate the effect of the twisted angle (θ) on the electronic structures of two types of 1T-TaS2 bilayers. Our calculation show that with the increase of twisted angles, the formation energy increases for the two types of structures and the band gap for Type II increases while the Type I structures experience a metal-semiconductor transition. The changes are mainly resulted from the interlayer interaction and the redistribution of cha...

**Source: **Physics Letters A - April 28, 2019 **Category: **Physics **Source Type: **research

**Nanoscale thermal cloaking by in-situ annealing silicon membrane**

Publication date: Available online 25 April 2019Source: Physics Letters AAuthor(s): Yida Liu, Yanhua Cheng, Run Hu, Xiaobing LuoAbstractWith the advent of thermal metamaterials, many new thermal functionalities have been proposed, like thermal cloaking, concentrating, etc. However, these thermal functionalities are based on the transformation thermotics or scattering cancellation technique, which, derived from Fourier's law, cannot apply to the micro-/nanoscale counterparts. In this paper, we design a nanoscale thermal cloak based on a crystalline silicon (Si) membrane and investigate the in-plane phonon transport via non-...

**Source: **Physics Letters A - April 27, 2019 **Category: **Physics **Source Type: **research

**Detecting chaos in fractional-order nonlinear systems using the smaller alignment index**

Publication date: Available online 25 April 2019Source: Physics Letters AAuthor(s): Shaobo He, Kehui Sun, Yuexi PengAbstractThe identification between chaos and ordered states in fractional-order chaotic systems is a challenge as well as a hot topic due to the complex of fractional calculus. In this paper, the smaller alignment index (SALI) is developed to detect chaos in the fractional-order chaotic systems by introducing the fractional-order tangent systems. Numerical simulation is carried out based on the fractional-order simplified Lorenz system and the fractional-order Hénon map, which are continuous chaotic sy...

**Source: **Physics Letters A - April 27, 2019 **Category: **Physics **Source Type: **research

**Magnetic behavior, Griffiths phase and magneto-transport study in 3d based nano-crystalline double perovskite Pr2CoMnO6**

Publication date: Available online 24 April 2019Source: Physics Letters AAuthor(s): Ilyas Noor Bhatti, Imtiaz Noor Bhatti, Rabindra Nath Mahato, M.A.H. AhsanAbstractDouble perovskite (DP) oxide material receive extensive research interest due to exciting physical properties with potential technological application. 3d based DP oxides are promising for exciting physics like magnetodielectric, ferroelectric, Griffiths phase, etc., specially Co/Mn DPs are gaining much research interest. In this paper we present the study of magnetic phase and transport properties in nano-crystalline Pr2CoMnO6 a 3d based double perovskite comp...

**Source: **Physics Letters A - April 26, 2019 **Category: **Physics **Source Type: **research

**Exchange bias behavior and magnetocaloric effect in Ni2In-type Mn7Sn4 alloy**

Publication date: Available online 24 April 2019Source: Physics Letters AAuthor(s): Zhishuo Zhang, Xiaohua Luo, Ying Song, Kai Liu, Shengcan Ma, Changcai Chen, Yuxi Zhang, Hai Zeng, Xuanwei Zhao, Qingzheng Jiang, Sajjad Ur Rehman, Zhenchen ZhongAbstractIn this work, the exchange bias behavior and magnetocaloric effect have been studied in Mn7Sn4 alloy. The X-ray powder diffraction pattern recorded at room temperature indicates that the sample crystallizes in a single phase with Ni2In-type hexagonal structure (space group P63/mmc). The maximum magnetic entropy change value across paramagnetic/ferrimagnetic transition is abo...

**Source: **Physics Letters A - April 26, 2019 **Category: **Physics **Source Type: **research

**Quantum algorithm for total least squares data fitting**

Publication date: Available online 24 April 2019Source: Physics Letters AAuthor(s): Hefeng Wang, Hua XiangAbstractThe total least squares (TLS) method is widely used in data-fitting. Compared with the least squares fitting method, the TLS fitting takes into account not only observation errors, but also errors from the measurement matrix of the variables. In this work, the TLS problem is transformed to finding the ground state of a Hamiltonian matrix. We propose quantum algorithms for solving this problem based on quantum simulation of resonant transitions. Our algorithms can achieve at least polynomial speedup over the kno...

**Source: **Physics Letters A - April 26, 2019 **Category: **Physics **Source Type: **research

**Gauge-free electromagnetic gyrokinetic theory**

Publication date: Available online 23 April 2019Source: Physics Letters AAuthor(s): J.W. Burby, A.J. BrizardAbstractA new gauge-free electromagnetic gyrokinetic theory is developed, in which the gyrocenter equations of motion and the gyrocenter phase-space transformation are expressed in terms of the perturbed electromagnetic fields, instead of the usual perturbed potentials. Gyrocenter polarization and magnetization are derived explicitly from the gyrocenter Hamiltonian, up to first order in the gyrocenter perturbation expansion. Expressions for the sources in Maxwell's equations are derived in a form that is suitable for...

**Source: **Physics Letters A - April 25, 2019 **Category: **Physics **Source Type: **research

**Simply modified GKL density classifiers that reach consensus faster**

Publication date: Available online 23 April 2019Source: Physics Letters AAuthor(s): J. Ricardo G. MendonçaAbstractThe two-state Gacs-Kurdyumov-Levin (GKL) cellular automaton has been a staple model in the study of complex systems due to its ability to classify binary arrays of symbols according to their initial density. We show that a class of modified GKL models over extended neighborhoods, but still involving only three cells at a time, achieves comparable density classification performance but in some cases reach consensus more than twice as fast. Our results suggest the time to consensus (relative to the length ...

**Source: **Physics Letters A - April 25, 2019 **Category: **Physics **Source Type: **research

**Finite-time synchronization of memristor-based complex-valued neural networks with time delays**

Publication date: Available online 23 April 2019Source: Physics Letters AAuthor(s): Kaili Sun, Song Zhu, Yongchang Wei, Xiaoke Zhang, Fei GaoAbstractThis paper deals with the problem of finite-time synchronization of memristor-based complex-valued neural networks (MCVNNs) with time delays. Based on the theory of differential inclusions with discontinuous right-hand side, we establish a new algebraic criterion of the finite-time synchronization of memristor-based complex-valued neural networks with time delays. The obtained theoretical results complement and improve some existing achievements in the real number field. Meanw...

**Source: **Physics Letters A - April 25, 2019 **Category: **Physics **Source Type: **research

**A novel dynamic model on power failure propagation and its application to load shedding optimization**

Publication date: Available online 23 April 2019Source: Physics Letters AAuthor(s): Shihao Nie, Li Ding, Mingyu Huang, Ping HuAbstractIn this letter, we proposed a novel individual-based dynamical model to study failure propagation in power system. In this model, a transmission line fails with a probability related to additional load transferred by other failed lines, where load upon failure of power lines is based on global and equal redistribution. Besides, the line recovers with a certain probability, and the failure levels of lines is depicted as a probability rather than a Boolean value subject to the mean-field theor...

**Source: **Physics Letters A - April 25, 2019 **Category: **Physics **Source Type: **research

**Investigation of velocity overshoot behavior in p-i-n GaAs semiconductor: The contribution of internal electric field**

Publication date: Available online 23 April 2019Source: Physics Letters AAuthor(s): Nguyen Phuoc The, Ho Khac HieuAbstractIn this work, we present the investigation of the velocity overshoot behavior in p-i-n GaAs semiconductor based on the ensemble Monte Carlo simulations. Our simulations with high-resolution of time and spatial show that the velocity overshoot effect is originated from internal electric field caused by the difference of carrier density. And this effect is dependent not only on the carrier density but also on temperature. Furthermore, we have observed the velocity relaxation effect which was not recognize...

**Source: **Physics Letters A - April 25, 2019 **Category: **Physics **Source Type: **research

**Flux modulated flat band engineering in square-kagomé ladder network**

Publication date: Available online 23 April 2019Source: Physics Letters AAuthor(s): Atanu Nandy, Amrita MukherjeeAbstractThe origin of non-dispersive flat band modes for a quasi-one dimensional square-kagomé ladder network is explored analytically by virtue of the real space renormalization group (RSRG) technique. A section of the eigenstates is non-diffusive i.e., localized within a cluster of sub-lattice sites partly by the destructive type of quantum interference and partly by the physical boundary created by the site with zero wave function amplitude. By making the amplitude vanish at the selective sites it beco...

**Source: **Physics Letters A - April 25, 2019 **Category: **Physics **Source Type: **research

**Shocks in an electronegative plasma with Boltzmann negative ions and κ-distributed trapped electrons**

Publication date: Available online 24 April 2019Source: Physics Letters AAuthor(s): Shaukat Ali Shan, Nadia ImtiazAbstractWe derived a Schamel-Burgers equation to study the dynamics of nonlinear structures in dissipative electronegative plasma having Boltzmann negative ions and κ- distributed trapped electrons. A recently introduced Tangent hyperbolic method has been employed to get the solutions of the differential equations which contain fractional nonlinearity. The effects of different physical parameters particularly, the kinematic viscosity, the superthermality, the trapping efficiency and the electronegativity ...

**Source: **Physics Letters A - April 25, 2019 **Category: **Physics **Source Type: **research

**Microstructure, magnetic and magnetocaloric properties in magnetic-field-induced martensitic transformation Mn1−xCo1+xGe alloy ribbons**

Publication date: Available online 19 April 2019Source: Physics Letters AAuthor(s): Chicheng Ma, Qing Ge, Kai Liu, Nan Ye, Jiancheng TangAbstractThe sharp field-induced metamagnetic martensitic transformation plays a pivotal role in magnetoresponsive effects for ferromagnetic shape memory alloys (FSMAs). Homogeneous polycrystalline Mn1−xCo1+xGe alloy ribbons are prepared by using the arc-melting and melt-spinning technique in this work. The microstructure, crystalline structure, magnetic and magnetocaloric properties are studied in these ribbons. The substitution of Co for Mn reduces the structural transformation tem...

**Source: **Physics Letters A - April 21, 2019 **Category: **Physics **Source Type: **research

**Neutron emission from fracturing of granite blocks: An experimental revisitation**

Publication date: Available online 18 April 2019Source: Physics Letters AAuthor(s): P. Benetti, F. Boffelli, C. Marciano, A. Piazzoli, G.L. RaselliAbstractA series of experimental tests, such as those of Carpinteri et al. (2013), have been performed. The aim was to check the emission of neutrons in the fracture of Luserna granite blocks under mechanical loading, as reported by the above mentioned authors. No neutrons have been detected and some doubts have emerged on the soundness of the previous measurements. (Source: Physics Letters A)

**Source: **Physics Letters A - April 19, 2019 **Category: **Physics **Source Type: **research