**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

**Origin of negative temperatures in systems interacting with external fields**

Publication date: Available online 18 April 2019Source: Physics Letters AAuthor(s): Salvatore Calabrese, Amilcare PorporatoAbstractThe controversial existence of negative temperatures has stirred interesting debates that have reached the foundations of thermodynamics, including questions on the second law, the Carnot efficiency and the statistical definition of entropy. Here we show that for systems interacting with an external field, negative temperatures may arise when the interaction energy with the field is treated as a form of internal energy. We discuss how negative temperatures are avoided when using a thermodynamic...

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

**Editors**

Publication date: 23 May 2019Source: Physics Letters A, Volume 383, Issue 15Author(s): (Source: Physics Letters A)

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

**Non-autonomous Hénon-Heiles system from Painlevé class**

Publication date: Available online 17 April 2019Source: Physics Letters AAuthor(s): Maciej BłaszakAbstractWe show how to deform separable Hénon-Heiles system with isospectral Lax representation, related with the stationary flow of the 5th-order KdV, to respective non-autonomous systems of Painlevé type with isomonodromic Lax representation. (Source: Physics Letters A)

**Source: **Physics Letters A - April 18, 2019 **Category: **Physics **Source Type: **research

**Non-local quantum functions and the distributed Deutsch-Jozsa algorithm**

Publication date: Available online 16 April 2019Source: Physics Letters AAuthor(s): Andrei Tănăsescu, Mihai-Zicu Mina, Pantelimon George PopescuAbstractNon-local implementations of quantum gates are a vital part of quantum networks. We find an optimal non-local implementation of quantum functions, the quantum gate equivalent of a switch statement. Then, we apply this result to the Deutsch-Jozsa problem, obtaining a distributed Deutsch-Jozsa algorithm and we show the relative efficiency improvement. As an application, we find a non-cooperative game based upon the original Deutsch-Jozsa problem where a classical agent has ...

**Source: **Physics Letters A - April 17, 2019 **Category: **Physics **Source Type: **research

**Spin transport properties in Fe-doped graphene/hexagonal boron-nitride nanoribbons heterostructures**

Publication date: Available online 16 April 2019Source: Physics Letters AAuthor(s): Mei Wang, Xinxin Jiang, Xiaoteng Li, Dongmei Li, Bin Cui, Desheng LiuAbstractBy combining non-equilibrium Green's function (NEGF) with density functional theory (DFT), we systematically study the spin-related transport properties of the heterostructures composed of graphene and hexagonal boron-nitride (h-BN) when the metal Fe is doped different positions of the heterostructures interface. The results show that the heterostructures exhibit obvious spin-filtering effect (SFE) and negative differential resistance (NDR) due to the different abs...

**Source: **Physics Letters A - April 17, 2019 **Category: **Physics **Source Type: **research

**Photocurrent in single walled carbon nanotubes**

In this study, photoresponse in semiconducting single-walled carbon nanotubes is investigated using density functional theory. The photocurrent generated is found to increase with the increasing electrode voltage at a constant flux. In all models the current increases uniformly with applied voltage and maximum value of current is found in the pristine CNT model, however the magnitude of photocurrent decreases in the homogenously nitrogen and boron doped models. Moreover, the photocurrent increases with increase in flux showing photoresistive property in CNTs. The spectral peaks appear at different wavelengths in the three ...

**Source: **Physics Letters A - April 17, 2019 **Category: **Physics **Source Type: **research

**Stratification phenomenon in an inclined rheology of UCM nanomaterial**

Publication date: Available online 16 April 2019Source: Physics Letters AAuthor(s): Aamir Ali, Mehvish Nazir, Muhammad Awais, Aqsa, M.Y. MalikAbstractThis investigation presents the unsteady rheology of Maxwell nanomaterial induced to flow over an inclined surface. Simultaneous effects of stratification, thermal radiation, heat source/sink and magnetic field are taken into account. Viscous dissipation and mixed convection due to concentration and temperature differences are also analyzed. The governing partial differential equations for the Maxwell nanofluid which incorporate the effects of Brownian and thermophoresis effe...

**Source: **Physics Letters A - April 17, 2019 **Category: **Physics **Source Type: **research

**Vertex configuration rules to grow an octagonal Ammann–Beenker tiling**

Publication date: Available online 15 April 2019Source: Physics Letters AAuthor(s): Cheng Cai, Longguang Liao, Xiujun FuAbstractBased on vertex configurations in the Ammann–Beenker tiling, we propose an algorithm for aggregation of square and rhombus tiles to generate an octagonal quasilattice, which mimics the growth process of a two-dimensional quasicrystal. Local matching rules with configuration selection are used to guide the way that tiles are joined to a cluster and form Ammann lines according to a generalized Fibonacci sequence. Our results reveal that vertex configuration selection can improve the performanc...

**Source: **Physics Letters A - April 16, 2019 **Category: **Physics **Source Type: **research

**Why cannot all divalent cations completely substitute the Pb cations of CH3NH3PbI3 perovskite?**

Publication date: Available online 12 April 2019Source: Physics Letters AAuthor(s): Denghui Ji, Shuling Wang, Hong Zhang, Huaying Wang, Buqin Zhang, Congmin Zhang, Xiuling LiAbstractOrganic-inorganic hybrid CH3NH3PbI3 perovskite has a great potential for applications in low-cost photovoltaic devices. However, the doped and substitution of Pb sites in CH3NH3PbI3 has not been widely reported. In this article, a quantum mechanical model was applied to determine why all divalent cations cannot substitute the Pb cations of CH3NH3PbI3 perovskite. The evaluation was performed by comparison the model with experimental results. On ...

**Source: **Physics Letters A - April 13, 2019 **Category: **Physics **Source Type: **research

**Perfect spin-filtering in p-aminophenol functionalized zigzag graphene nanoribbons: The role of sp3 hybridized nitrogen**

Publication date: Available online 12 April 2019Source: Physics Letters AAuthor(s): Zhi-Ang Jia, Xiao-Fei Li, Xinrui Cao, Xiang-Hua Zhang, Zhiyong WangAbstractCovalent functionalization of graphene is recently developed from the formation of sp3 hybridized carbon atom (sp3-C) to the sp3 hybridized nitrogen (sp3-N) at the anchoring site. Here, we investigated the electronic structures and transport properties of the zigzag graphene nanoribbons functionalized by covalently bonding of p-aminophenol (p-AP) molecule. First principles results demonstrate that the formed sp3-N plays a vital role in determining the electronic stru...

**Source: **Physics Letters A - April 13, 2019 **Category: **Physics **Source Type: **research

**Spin-dependent transport properties of debrominated tetrabromopolyaromatic with Cu or Co doping embedded between zigzag graphene nanoribbon electrodes**

Publication date: Available online 12 April 2019Source: Physics Letters AAuthor(s): Dongde Li, Xiaojiao Zhang, Mingjun Li, Haiming Duan, Bingchu Yang, Mengqiu LongAbstractUsing density functional theory combined with non-equilibrium Green's function method, we investigate the spin-dependent transport properties of debrominated tetrabromopolyaromatic (D-TBPA) molecules embedded between zigzag graphene nanoribbon electrodes, and the effects of copper and cobalt side doping have also been considered. Our results show that the copper doping can insert new energy levels around the Fermi Level and keep spin degeneration of band ...

**Source: **Physics Letters A - April 13, 2019 **Category: **Physics **Source Type: **research

**Magnetic field control of current through model graphene nanosheets**

Publication date: Available online 12 April 2019Source: Physics Letters AAuthor(s): Umesh Dhakal, Dhurba RaiAbstractWe study magnetic field control of current through model graphene nanosheet junctions within the framework of the tight-binding approximation. Geometrical asymmetry in the coupling of graphene nanosheets to the contact leads emerges as one of the most important determining factors for the magnetic field control of current. The asymmetric connection split the otherwise degenerate energy levels of the structures leading to energy-resolved transmission peaks which the applied field modulates for a transmission m...

**Source: **Physics Letters A - April 13, 2019 **Category: **Physics **Source Type: **research

**A maximum algebraic connectivity increment edge-based strategy for capacity enhancement in scale-free networks**

Publication date: Available online 12 April 2019Source: Physics Letters AAuthor(s): Gang Li, Zhi Feng Hao, Han Huang, Hang Wei, Xue Ming YanAbstractIn this paper, we focus on how to improve transportation efficiency of scale-free networks via edge increments. Based on analyzing the correlation between algebraic connectivity, which is the second smallest eigenvalue of the graph Laplacian matrix, and traffic capacity, we propose an effective edge-addition strategy called maximum algebraic connectivity increment edge (MACIE). Existing approaches are based on topological structure parameters, such as path and degree of a netwo...

**Source: **Physics Letters A - April 13, 2019 **Category: **Physics **Source Type: **research

**Topological states in the Hofstadter model on a honeycomb lattice**

Publication date: Available online 13 April 2019Source: Physics Letters AAuthor(s): Igor N. KarnaukhovAbstractWe provide a detailed analysis of a topological structure of a fermion spectrum in the Hofstadter model with different hopping integrals along the x,y,z-links (tx=t,ty=tz=1), defined on a honeycomb lattice. We have shown that the chiral gapless edge modes are described in the framework of the generalized Kitaev chain formalism, which makes it possible to calculate the Hall conductance of subbands for different filling and an arbitrary magnetic flux ϕ. At half-filling the gap in the center of the fermion spectrum o...

**Source: **Physics Letters A - April 13, 2019 **Category: **Physics **Source Type: **research

**Explosive synchronization through dynamical environment**

We report the emergence of an explosive synchronization transition in the identical oscillators interacting indirectly through a network of dynamical agents. The transition from incoherent state to coherent state and vice–versa in these coupled oscillator exhibits an abrupt as well as irreversible. Such transition depends on the network topology as well as the interaction between the oscillators and dynamical agents rather than degree-frequency correlation in the network of oscillators. The occurrence of explosive synchronization is studied in details by using an appropriate order parameter for limit-cycle oscillator...

**Source: **Physics Letters A - April 13, 2019 **Category: **Physics **Source Type: **research

**The geometric potential of a double-frequency corrugated surface**

Publication date: Available online 11 April 2019Source: Physics Letters AAuthor(s): Wei-ran Cao, Yong-long Wang, Xiao-Lei Chen, Hua Jiang, Chang-Tan Xu, Hong-Shi ZongAbstractFor an electron confined to a surface reconstructed by double-frequency corrugations, we give the effective Hamiltonian by the formula of geometric influences, obtain an additive scalar potential induced by curvature that consists of attractive wells with different depth. The difference is generated by the multiple frequency of the double-frequency corrugation. Subsequently, we investigate the effects of geometric potential on the transmission probabil...

**Source: **Physics Letters A - April 13, 2019 **Category: **Physics **Source Type: **research

**Effective spin-2 quasi-particles at linear dispersive five-fold degenerate points with tunable topological Chern numbers**

Publication date: Available online 11 April 2019Source: Physics Letters AAuthor(s): Cheng Feng, Qiang Wang, S.N. Zhu, Hui LiuAbstractIn this work, which is based on spin-2 vectors and traceless spin-2 tensors, an effective Hamiltonian is constructed with a linearly dispersive five-fold degenerate point with spin-2 vector-momentum couplings. For the model without spin-2 vector-tensor coupling, the topological Chern numbers of five bands are calculated as 4, 2, 0, −2, −4. After including spin-2 vector-tensor coupling, separate topological Chern numbers are obtained for different couplings. A cubic lattice of atom...

**Source: **Physics Letters A - April 13, 2019 **Category: **Physics **Source Type: **research

**Monte Carlo simulation of electric conductivity for pure and doping fullerene (C60)**

Publication date: Available online 10 April 2019Source: Physics Letters AAuthor(s): Zakarya Berkai, Mebarka Daoudi, Nesrine Mendil, Abderrahmane BelghachiAbstractIn this paper, we have used Monte Carlo (MC) method to simulate and study the temperature and doping effects on the electric conductivity of fullerene (C60). The results show that the band gap has reduced by the doping and the charge carrier transport is facilitated from valence band to conduction band by the temperature where is touched a 300 K. In this case, the conductivity reached a value of 4×10−7Scm−1. The electric conductivity of C60 can i...

**Source: **Physics Letters A - April 11, 2019 **Category: **Physics **Source Type: **research

**One-dimensional structure of multi-component fine particle (dust) clouds under gravity**

Publication date: Available online 10 April 2019Source: Physics Letters AAuthor(s): Hiroo TotsujiAbstractThe structure of electrostatic potential and the distribution of fine particle (dust) clouds are analyzed in the case where we have fine particles of multiple components in plasmas under gravity. This extends the model for one-dimensional structures of fine particle cloud based on the enhanced charge neutrality in clouds to multi-species cases. Fine particles of different species are shown to form stratified clouds with simply expressed mutual separations. The results may be applied to analyze or segregate mixtures of d...

**Source: **Physics Letters A - April 11, 2019 **Category: **Physics **Source Type: **research

**Interplay of electron-electron and electron-phonon interactions in molecular junctions**

Publication date: Available online 10 April 2019Source: Physics Letters AAuthor(s): Amir Eskandari-aslAbstractIn this work we consider a current carrying molecular junction with both electron-phonon and electron-electron interactions taken into account. After performing Lang-Firsov transformation and considering Markov approximations in accordance to weak coupling to the electronic leads, we obtain the master equation governing the time evolution of the reduced density matrix of the junction. The steady state of the density matrix can be used to obtain I-V characteristic of the junction in several regimes of strengths of t...

**Source: **Physics Letters A - April 11, 2019 **Category: **Physics **Source Type: **research

**Universal transition to inactivity in global mixed coupling**

Publication date: Available online 9 April 2019Source: Physics Letters AAuthor(s): K. Yadav, N.K. Kamal, M.D. ShrimaliAbstractThe collective dynamics of a network of nonlinear oscillators can be represented in terms of activity level of the network. We have studied a universal transition from activity to inactivity in a globally coupled network of identical oscillators. We consider mixed coupling, where some of the network elements interact through the similar variables while others with dissimilar variables. The coupling strength at which the network become inactive is inversely proportional to the ratio of number of elem...

**Source: **Physics Letters A - April 11, 2019 **Category: **Physics **Source Type: **research

**Few-body quantum method in a d-dimensional space**

Publication date: Available online 8 April 2019Source: Physics Letters AAuthor(s): E. Garrido, A.S. Jensen, R. Álvarez-RodríguezAbstractIn this work we investigate the continuous confinement of quantum systems from three to two dimensions. Two different methods will be used and related. In the first one the confinement is achieved by putting the system under the effect of an external field. This method is conceptually simple, although, due to the presence of the external field, its numerical implementation can become rather cumbersome, especially when the system is highly confined. In the second method the ex...

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

**Editors**

Publication date: 9 May 2019Source: Physics Letters A, Volume 383, Issue 14Author(s): (Source: Physics Letters A)

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

**Nonclassicality in off-resonant Raman process**

Publication date: Available online 5 April 2019Source: Physics Letters AAuthor(s): Kishore Thapliyal, Jan PeřinaAbstractThe detuning parameter in experimentally feasible off-resonant Raman process is shown as a control parameter to probe and enhance the nonclassicality generated in the output of the process. Specifically, the normal characteristic function is obtained for the process as a function of detuning parameters in Stokes and anti-Stokes generation processes using more general solution than the conventional short-time solution under complete quantum treatment, which remains in the multimode Gaussian form. Single- ...

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

**Compressibility of random walker trajectories on growing networks**

Publication date: Available online 6 April 2019Source: Physics Letters AAuthor(s): Robert J.H. Ross, Charlotte Strandkvist, Walter FontanaAbstractWe find that the simple coupling of network growth to the position of a random walker on the network generates a traveling wave in the probability distribution of nodes visited by the walker. We argue that the entropy of this probability distribution is bounded as the network size tends to infinity. This means that the growth of a space coupled to a random walker situated in it constrains its dynamics to a set of typical random walker trajectories, and walker trajectories inside ...

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

**Ferromagnetic titanium doped black phosphorus**

Publication date: Available online 2 April 2019Source: Physics Letters AAuthor(s): Xiaohong Jiang, Xinwei Zhang, Zhenghe Hua, Dongqiang Han, Wenhua Zhao, Zhihe Wang, Shaoguang YangAbstractDiluted magnetic semiconductor (DMS) and layered material black phosphorus (BP) are two kinds of important materials. In this manuscript, it was reported on the observation of ferromagnetism in Ti-doped BP synthesized by high pressure method. Clear hysteresis loops were observed at room temperature. The Curie temperature was deduced to be 130-140 K. Transport studies showed us temperature dependent positive-to-negative magnetoresistance (...

**Source: **Physics Letters A - April 5, 2019 **Category: **Physics **Source Type: **research

**Luminescence property improvement of Ba2LaSbO6:Mn4+ phosphor by using Dy3+ or H3BO3**

Publication date: Available online 4 April 2019Source: Physics Letters AAuthor(s): Renping Cao, Longxiang Xu, Yaqin Ran, Xinyan Lv, Siling Guo, Hui Ao, Ting Chen, Zhiyang LuoAbstractBa2LaSbO6:Mn4+, Ba2LaSbO6:Mn4+, Dy3+, and Ba2LaSbO6:Mn4+, H3BO3 phosphors are synthesized in the air by high temperature solid state reaction method. The particle sizes and sintering degree of Ba2LaSbO6:Mn4+ phosphor may be changed by doping Dy3+ ion and H3BO3. When the small amount of Dy3+ ion and H3BO3 are codoped, the emission intensity of Ba2LaSbO6:Mn4+ phosphor can be enhanced 1.2–1.3 times and the quantum efficiency of Ba2LaSbO6:Mn4...

**Source: **Physics Letters A - April 5, 2019 **Category: **Physics **Source Type: **research

**Construction of noisy bound entangled states and the range criterion**

Publication date: Available online 4 April 2019Source: Physics Letters AAuthor(s): Saronath Halder, Ritabrata SenguptaAbstractIn this work we consider bipartite noisy bound entangled states with positive partial transpose, that is, such a state can be written as a convex combination of an edge state and a separable state. In particular, we present schemes to construct distinct classes of noisy bound entangled states which satisfy the range criterion. As a consequence of the present study we also identify noisy bound entangled states which do not satisfy the range criterion. All of the present states are constituted by expl...

**Source: **Physics Letters A - April 5, 2019 **Category: **Physics **Source Type: **research

**Prediction of interface states in liquid surface waves with one-dimensional modulation**

Publication date: Available online 4 April 2019Source: Physics Letters AAuthor(s): Xi Shi, Yong Sun, Chunhua Xue, Xinhua HuAbstractWe theoretically study the interface states of liquid surface waves propagating over the heterojunctions formed by a bottom with one-dimensional periodic undulations. By considering the periodic structure as a homogeneous one, our systematic study shows that the signs of the effective depth and gravitational acceleration are opposite within the band gaps whether the structure is symmetric or not. Those effective parameters can be used to predict the interface states which could amplify the ampl...

**Source: **Physics Letters A - April 5, 2019 **Category: **Physics **Source Type: **research

**Explosive synchronization in through dynamical environment**

We report the emergence of an explosive synchronization transition in the identical oscillators interacting indirectly through a network of dynamical agents. The transition from incoherent state to coherent state and vice–versa in these coupled oscillator exhibits an abrupt as well as irreversible. Such transition depends on the network topology as well as the interaction between the oscillators and dynamical agents rather than degree-frequency correlation in the network of oscillators. The occurrence of explosive synchronization is studied in details by using an appropriate order parameter for limit-cycle oscillator...

**Source: **Physics Letters A - April 5, 2019 **Category: **Physics **Source Type: **research

**Spin polarization and temperature dependence of electron effective mass in quantum wires**

Publication date: Available online 4 April 2019Source: Physics Letters AAuthor(s): Le Van-Tan, Trieu Van Thang, Nguyen Duy Vy, Huy Thien CaoAbstractThe electron effective mass in GaAs quantum wires has been estimated by using a full dynamical random-phase approximation to examine its properties versus spin polarization, temperature, and carrier density. A decrease of mass with spin polarization is seen. The minority mass increases with the polarization while the majority mass decreases and this behaviour is seen for all densities. A maximal enhancement of mass at moderate temperature around 25 K is also presented. These ca...

**Source: **Physics Letters A - April 5, 2019 **Category: **Physics **Source Type: **research

**Variational approximations of soliton dynamics in the Ablowitz-Musslimani nonlinear Schrödinger equation**

Publication date: Available online 3 April 2019Source: Physics Letters AAuthor(s): Rahmi Rusin, Rudy Kusdiantara, Hadi SusantoAbstractWe study the integrable nonlocal nonlinear Schrödinger equation proposed by Ablowitz and Musslimani, that is considered as a particular example of equations with parity-time (PT) symmetric self-induced potential. We consider dynamics (including collisions) of moving solitons. Analytically we develop a collective coordinate approach based on variational methods and examine its applicability in the system. We show numerically that a single moving soliton can pass the origin and decay or b...

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

**Band gap tuning of defective silicon carbide nanotubes under external electric field: Density functional theory**

Publication date: Available online 3 April 2019Source: Physics Letters AAuthor(s): Jamal A. TallaAbstractWe have theoretically investigated the effect of applying longitudinal and transverse electric field on silicon carbide nanotubes with different orientations of Stone Wales defects. We found that each type of Stone Wales defects maintained different formation energy. We have also successfully proved that the orientation of Stone Wales defects in silicon carbide nanotubes response quite differently upon applying external electric field, whereas, two important and interesting phenomena were observed. First, the semiconduc...

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

**Stabilization of trapless Bose-Einstein condensates without any management**

Publication date: Available online 3 April 2019Source: Physics Letters AAuthor(s): Tamilthiruvalluvar Ramakrishnan, Sabari SubramaniyanAbstractIn higher dimensions, so far, both attractive and repulsive trapless Bose-Einstein condensates (BECs) have been stabilized with the help of temporal or spatial management of the two-body contact interaction. However, in the absence of nonlinear management, up to now, there is no model to stabilize the repulsive, trapless BECs at higher dimensions. Hence, in the present study, we tried to stabilize the same and achieved with help of the interplay between three-body and higher-order i...

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

**Enhancement of nanogripper performance by using soft material coating**

Publication date: Available online 3 April 2019Source: Physics Letters AAuthor(s): Hadi Ghattan Kashani, Mohammad Hossein Ghajar, Masoud ShariatPanahi, Sadegh SadeghzadehAbstractNanogrippers have been widely studied for their ability of grasping and manipulating nanoparticles and their capability to be utilized inside SEM, however, due to their very small dimensions, nanogrippers still have widespread complexity in controlling and grasping nanoparticles. In macro grippers, soft materials are used at the surface of end-effectors to reduce the probability of particles damaging, while in nanogrippers, there are limited choice...

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

**Ferromagnetic titanium doped black phosphorous**

Publication date: Available online 2 April 2019Source: Physics Letters AAuthor(s): Xiaohong Jiang, Xinwei Zhang, Zhenghe Hua, Dongqiang Han, Wenhua Zhao, Zhihe Wang, Shaoguang YangAbstractDiluted magnetic semiconductor (DMS) and layered material black phosphorous (BP) are two kinds of important materials. In this manuscript, it was reported on the observation of ferromagnetism in Ti-doped BP synthesized by high pressure method. Clear hysteresis loops were observed at room temperature. The Curie temperature was deduced to be 130-140 K. Transport studies showed us temperature dependent positive-to-negative magnetoresistance ...

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

**A simple, analytic solution of the semiclassical Rabi model in the red-detuned regime**

Publication date: Available online 2 April 2019Source: Physics Letters AAuthor(s): L.O. CastañosAbstractWe consider the semiclassical Rabi model in the large, red-detuned regime. Using the method of multiple-scales we obtain a simple, analytic, and approximate solution that describes the evolution of the system accurately for long times and for arbitrary values of the qubit-field coupling. It is used to characterize the probability to find the qubit in the excited state and the trajectory of the associated Bloch vector. Finally, we present physical situations where the results can be applied. (Source: Physics Letters A)

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

**Density–driven superfluid transition of the constrained bosons on a lattice**

Publication date: Available online 1 April 2019Source: Physics Letters AAuthor(s): T.K. KopećAbstractWe formulate the Landau theory and study its consequences for lattice bosons, which are stabilized by a three-body on-site constraint. This is relevant for experiments with cold atoms in optical lattices, where the presence of three-body dissipative loss processes renders the occupation number n for bosons on short timescales effectively constrained to n≤2. We elaborate on the Landau free energy expansion resulting from the Hamiltonian of bosons in the restricted Hilbert space, and present the phase diagram of the const...

**Source: **Physics Letters A - April 3, 2019 **Category: **Physics **Source Type: **research

**Resonance studies using the contour deformation method in the complex momentum plane**

Publication date: Available online 1 April 2019Source: Physics Letters AAuthor(s): Yu Kun Yang, Yong Wu, Yi Zhi Qu, Jian Guo Wang, R.K. Janev, Song Bin ZhangAbstractA contour deformation method (CDM) in the complex momentum plane has been successfully extended and implemented to probe resonances in atomic and molecular systems. Specifically, solution of the Schrödinger equation is performed in momentum space with momentum deformed on a contour in the complex plane. The bound, resonant, and complex continuum states could be directly revealed from the eigenvalues of the Schrödinger equation in the complex momentum ...

**Source: **Physics Letters A - April 3, 2019 **Category: **Physics **Source Type: **research