**Valley polarization enhancement and oscillation in asymmetric T junctions**

Publication date: Available online 22 March 2019Source: Physics Letters AAuthor(s): Qingtian Zhang, K.S. ChanAbstractWe studied the valley dependent transport in a T junction consisting of an armchair lead and two zigzag leads. Electrons transmitted from the armchair lead to the two outgoing zigzag leads can be valley polarized. When the two outgoing leads have different widths, electrons are pushed into the wider lead and as a result, the valley polarization of the current in the narrow lead is enhanced with an oscillatory dependence on energy. The oscillation pattern is determined by the widths of the two zigzag leads. W...

**Source: **Physics Letters A - March 24, 2019 **Category: **Physics **Source Type: **research

**Enhanced mobility of high-frequency discrete breathers in a monatomic chain with odd anharmonicity**

Publication date: Available online 22 March 2019Source: Physics Letters AAuthor(s): A. Shelkan, M. Klopov, V. HizhnyakovAbstractThe mobility of high-frequency discrete breathers in monatomic chains with nonlinear interatomic potentials of the nearest neighbors is considered. It was found that the odd (cubic and fifth) anharmonicity strongly affects the mobility of breathers, sharply increasing the distance that it propagates without being trapped. It was also found that the correctly chosen fifth anharmonicity leads to an inversion of stability between the bond-centered and site-centers breathers and to the low-radiative p...

**Source: **Physics Letters A - March 24, 2019 **Category: **Physics **Source Type: **research

**Molecular dynamics simulation of mechanical properties of nanocrystalline platinum: Grain-size and temperature effects**

Publication date: Available online 22 March 2019Source: Physics Letters AAuthor(s): Jiejie Li, Binbin Lu, Hongjian Zhou, Chenyao Tian, Yuehui Xian, Guoming Hu, Re XiaAbstractA series of molecular dynamics simulations has been carried out to study the mechanical properties of nanocrystalline platinum. The effects of average grain size and temperature on mechanical behaviors are discussed. The simulated uniaxial tensile results indicate the presence of a critical average grain size about 14.1 nm, for which there is an inversion of the conventional Hall-Petch relation at temperature of 300 K. The transition can be explained b...

**Source: **Physics Letters A - March 24, 2019 **Category: **Physics **Source Type: **research

**Lump, lumpoff and predictable rogue wave solutions to the (2+1)-dimensional asymmetrical Nizhnik-Novikov-Veselov equation**

Publication date: Available online 21 March 2019Source: Physics Letters AAuthor(s): Pinxia Wu, Yufeng ZhangAbstractThis paper mainly uses Hirota bilinear form to investigate the (2+1)-dimensional asymmetrical Nizhnik-Novikov-Veselov equation. We obtain the general lump solutions and discuss its positiveness, the propagation path, amplitude and position at any time. Based on the general lump solutions, lumpoff solutions which a combination of lump solitons and stripe solitons, are also triumphantly acquired. Similarly, according to the general lump solutions, we are also consider a particular rogue wave by introducing a pai...

**Source: **Physics Letters A - March 23, 2019 **Category: **Physics **Source Type: **research

**Frozen entanglement and quantum correlations of one-parameter qubit−qutrit states under classical noise effects**

Publication date: Available online 21 March 2019Source: Physics Letters AAuthor(s): Martin Tchoffo, Arthur Tsamouo Tsokeng, Odette Melachio Tiokang, Pernel Nguenang Nganyo, Lukong Cornelius FaiAbstractWe provide a detailed analysis of the dynamics of entanglement and quantum correlations for one-parameter qubit-qutrit states under independent or common classical noises influence. Namely the static noise, the Ornstein-Uhlenbeck (OU) noise and the random telegraph noise. Independently of the intrinsic features of the noises, entanglement measured by negativity and quantum correlations measured by measured-induced disturbance...

**Source: **Physics Letters A - March 23, 2019 **Category: **Physics **Source Type: **research

**Magnetic circular dichroism and absorption spectra of I85→F55 transition in HoAl3(BO3)4 and HoFe3(BO3)4 single crystals**

Publication date: Available online 20 March 2019Source: Physics Letters AAuthor(s): A.V. Malakhovskii, V.V. Sokolov, I.A. Gudim, M.V. RautskiiAbstractComparative study of magnetic circular dichroism (MCD) and absorption spectra of HoAl3(BO3)4 and HoFe3(BO3)4 single crystals in the region of I85→F55 transition of the Ho3+ ion was carried out. Absorption spectra were decomposed into the Lorentz shape components and intensities of transitions were obtained. Unusually strong vibronic transitions were observed in HoAl3(BO3)4, but were not observed in HoFe3(BO3)4 that testified to the strong non diagonal vibronic interactio...

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

**On the stability of a classical plasma**

Publication date: Available online 20 March 2019Source: Physics Letters AAuthor(s): M. Apostol, L.C. CuneAbstractA linearized self-consistent variational approach is employed to investigate the (thermodynamic) stability of a classical plasma (electrons and positive ions). It is shown, by using this approach, that a classical plasma, which consists of ions “dressed” with electrons, has a well-defined thermodynamics. In the strong-coupling regime the “plasma” is a solid, while, on passing to the weak-coupling regime, it becomes gradually a liquid, a non-ideal gas, and, finally, in the weak-coupling li...

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

**First digit law from Laplace transform**

Publication date: Available online 20 March 2019Source: Physics Letters AAuthor(s): Mingshu Cong, Congqiao Li, Bo-Qiang MaAbstractThe occurrence of digits 1 through 9 as the leftmost nonzero digit of numbers from real-world sources is distributed unevenly according to an empirical law, known as Benford's law or the first digit law. It remains obscure why a variety of data sets generated from quite different dynamics obey this particular law. We perform a study of Benford's law from the application of the Laplace transform, and find that the logarithmic Laplace spectrum of the digital indicator function can be approximately...

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

**Exact analytical results for density profile in Fourier space and elastic scattering function of a rotating harmonically confined ultra-cold Fermi gas**

Publication date: Available online 20 March 2019Source: Physics Letters AAuthor(s): S. Medjedel, K. BencheikhAbstractIn this paper, the system dealt with consisting of an ultra-cold neutral spin-polarized Fermi gas undergoing rotation (or in the so-called synthetic magnetic field) trapped by an anisotropic harmonic potential in a two and three-dimensional space at zero temperature. Using the so-called Bloch propagator as a tool, we derive exact closed-form expressions for particle density in Fourier space which are valid for an arbitrary particle number confined by a two and three-dimensional rotating anisotropic harmonic ...

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

**A new bifurcation in non-smooth continuous system inducing semi-limit cycle**

This study enriches the knowledge of bifurcation analysis for non-smooth dynamical systems. (Source: Physics Letters A)

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

**A new lattice hydrodynamic model accounting for the traffic interruption probability on a gradient highway**

Publication date: Available online 20 March 2019Source: Physics Letters AAuthor(s): Qingying Wang, Rongjun Cheng, Hongxia GeAbstractIn this paper, a novel lattice hydrodynamic model is presented by accounting for the traffic interruption probability on a gradient highway. The stability condition can be obtained by the use of linear analysis. Linear analysis demonstrates that the traffic interruption probability and the slope will affect the stability region. Through nonlinear analysis, the mKdV equation is derived to describe the phase transition of traffic flow. Furthermore, the numerical simulation is carried out, and th...

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

**A broadband planar acoustic metamaterial lens**

Publication date: Available online 19 March 2019Source: Physics Letters AAuthor(s): Hui Yuan Dong, Jin Wang, Gang Yong Song, Wen Xuan Tang, Qiang ChengAbstractBased on quasi-conformal mapping approach, we propose a two-dimensional broadband and low-loss planar lens in the acoustic regime, which can be realized using gradient-index sub-wavelength artificial structures with hard boundary. In this design, QCM is employed in the acoustic regime to convert a parabolic form into a planar one, which makes the resultant material approximately isotropic through minimizing the anisotropic factor. It is found that the planar lens can...

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

**Equal heartbeat intervals and their effects on the nonlinearity of permutation-based time irreversibility in heart rate**

Publication date: Available online 7 March 2019Source: Physics Letters AAuthor(s): Wenpo Yao, Wenli Yao, Jun WangAbstractThe association of equal heartbeat intervals with cardiac conditions and the effect of the equality on permutation-based time irreversibility are investigated in this paper. We measure the distributions of equal heartbeat intervals under three conditions, namely congestive heart failure (CHF), healthy young and elderly, whose time irreversibility is detected by measuring the probabilistic difference between permutations instead of raw vectors. We demonstrate that heartbeats contain high rates of equal st...

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

**A new method for finding cycles by semilinear control**

Publication date: Available online 18 March 2019Source: Physics Letters AAuthor(s): Dmitriy Dmitrishin, Ivan Skrinnik, Goran Lesaja, Alex StokolosAbstractIn the paper two new results that prove typically real and local univalent properties of certain class of rational functions in the unit disc D are presented. They provide a theoretical justification of a new method for finding periodic solutions of the discrete vector dynamical systems. The main goal of the paper is to propose and investigate the two-delays generalization of the scheme introduced by Ö. Morgül. The analysis shows that the coefficients in the pro...

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

**Quantum communication through chains with diluted disorder**

Publication date: Available online 15 March 2019Source: Physics Letters AAuthor(s): P.R.S. Júnior, G.M.A. Almeida, M.L. Lyra, F.A.B.F. de MouraAbstractWe investigate a single-qubit state transfer protocol along a channel featuring diagonal diluted disorder. In the regime where the source and destination sites are weakly coupled to the channel, we report the possibility of transmitting quantum states with high fidelity as well as establishing end-to-end entanglement in that sort of configuration. We further discuss how the performance of the protocol depends upon the availability of extended states within the disorde...

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

**Universal quantum uncertainty relations: Minimum-uncertainty wave packet depends on measure of spread**

Publication date: Available online 15 March 2019Source: Physics Letters AAuthor(s): Anindita Bera, Debmalya Das, Aditi Sen(De), Ujjwal SenAbstractBased on the statistical concept of the median, we propose a quantum uncertainty relation between semi-interquartile ranges of the position and momentum distributions of arbitrary quantum states. The relation is universal, unlike that based on the mean and standard deviation, as the latter may become non-existent or ineffective in certain cases. We show that the median-based one is not saturated for Gaussian distributions in position. Instead, the Cauchy-Lorentz distributions in ...

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

**Composition law for the Cole-Cole relaxation and ensuing evolution equations**

Publication date: Available online 15 March 2019Source: Physics Letters AAuthor(s): K. Górska, A. Horzela, A. LattanziAbstractPhysically natural assumption says that any relaxation process taking place in the time interval [t0,t2], t2>t0≥0 may be represented as a composition of processes taking place during time intervals [t0,t1] and [t1,t2] where t1 is an arbitrary instant of time such that t0≤t1≤t2. For the Debye relaxation such a composition is realized by usual multiplication which claim is not valid any longer for more advanced models of relaxation processes. We investigate the composition law requi...

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

**On the numerical solution of nonplanar dust-acoustic super rogue waves in a strongly coupled dusty plasma**

Publication date: Available online 15 March 2019Source: Physics Letters AAuthor(s): Salemah Almutalk, S.A. El-Tantawy, E.I. El-Awady, S.K. El-LabanyAbstractThe occurrence of cylindrical and spherical low-frequency dust-acoustic freak waves (DAFWs) in a strongly coupled dusty plasma is numerically investigated in the framework of the phenomenological generalized hydrodynamic model. The basic equations are reduced to a modified/nonplanar nonlinear Schrödinger equation (mNLSE) using a reductive perturbation method. The existing regions of instability structures have been carefully identified. For studying the propagation...

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

**Time delay induced partial death patterns with conjugate coupling in relay oscillators**

Publication date: Available online 15 March 2019Source: Physics Letters AAuthor(s): Amit SharmaAbstractWe investigate the dynamics of delay-coupled relay oscillators with conjugate (or dissimilar) coupling and find the partial death with the phase-flip transition. This phenomenon is quite general and occurs for the limit cycle as well as chaotic relay oscillators. In the regime of partial death, parts of the system oscillate with large amplitude, while other element stays at rest. Using the Stuart-Landau and Rössler oscillators, we demonstrate that partial amplitude death is a robust dynamical state in coupled oscilla...

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

**Editors**

Publication date: 10 April 2019Source: Physics Letters A, Volume 383, Issue 12Author(s): (Source: Physics Letters A)

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

**Equiprobable unambiguous discrimination of quantum states by symmetric orthogonalisation**

Publication date: Available online 13 March 2019Source: Physics Letters AAuthor(s): D.B. Horoshko, M.M. Eskandari, S.Ya. KilinAbstractWe show that the maximal probability of equiprobable unambiguous discrimination of a set of pure quantum states is given by the minimal eigenvalue of the Gram matrix of this set. We illustrate this result with several examples important for the protocols of quantum key distribution realized with weak coherent states of light. (Source: Physics Letters A)

**Source: **Physics Letters A - March 15, 2019 **Category: **Physics **Source Type: **research

**Is an interacting ground state (pure state) v-representable density also non-interacting ground state v-representable by a Slater determinant? In the absence of degeneracy, yes!**

Publication date: Available online 13 March 2019Source: Physics Letters AAuthor(s): A. GonisAbstractIt is shown that in the absence of degeneracy a density, n(r), describing the probability of finding a particle in a small volume at position, r, that is known to be pure-state v-representable in terms of the ground state of an interacting system of particles evolving under an external potential, v(r), is also pure state v-representable in terms of a single Slater determinant describing the ground state of a system of non-interacting particles under a potential, vs(r). This establishes the validity of the Kohn–Sham for...

**Source: **Physics Letters A - March 15, 2019 **Category: **Physics **Source Type: **research

**On the dynamics of the q-deformed logistic map**

Publication date: Available online 8 March 2019Source: Physics Letters AAuthor(s): J. Cánovas, M. Muñoz-GuillermoAbstractWe analyze the q-deformed logistic map, where the q-deformation follows the scheme inspired in the Tsallis q-exponential function. We compute the topological entropy of the dynamical system, obtaining the parametric region in which the topological entropy is positive and hence the region in which chaos in the sense of Li and Yorke exists. In addition, it is shown the existence of the so-called Parrondo's paradox where two simple maps are combined to give a complicated dynamical behavior. (S...

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

**Equal heartbeat intervals and their effects on the nonlinearity of time irreversibility in heart rate**

Publication date: Available online 7 March 2019Source: Physics Letters AAuthor(s): Wenpo Yao, Wenli Yao, Jun WangAbstractThe association of equal heartbeat intervals with cardiac conditions and the effect of equality on the permutation-based time irreversibility are investigated in this paper. We measure the distributions of equal heartbeat intervals under three conditions, namely congestive heart failures (CHF), healthy young and elderly, whose nonlinearity is detected by measuring the probabilistic difference between permutations instead of raw symmetric vectors. We demonstrate that heartbeats contain high rates of equal...

**Source: **Physics Letters A - March 8, 2019 **Category: **Physics **Source Type: **research

**Impact of chloride treatment on the physical properties of polycrystalline thin CdTe films for solar cell applications**

This report presents the micro-structural, opto-electrical and surface morphological properties of e-beam evaporated thin CdTe films with the activation of post-chloride treatment. The thin films having thickness 800 nm were deposited onto glass and ITO substrates subsequently processed with CdCl2 treatment at various temperatures and then subjected to different characterization tools to investigate the physical properties. The films were found to be polycrystalline in nature having a cubic phase with preferred orientation (111) up to 320 °C and completely oxidized at 470 °C while the ohmic nature of film...

**Source: **Physics Letters A - March 8, 2019 **Category: **Physics **Source Type: **research

**Investigations of physical aspects of spinel ABi2O4 (A=Zn, Cd) oxides via ab-initio calculations**

Publication date: Available online 7 March 2019Source: Physics Letters AAuthor(s): M. Waseem, I. Mahmood, Muhammad Rashid, Irfan Qasim, A. LarefAbstractThis present study aims to unravel physical properties of spinel oxides in cubic phase represented by general empirical formula of ABi2O4 (A=Zn, Cd) using full potential lineralized augmented plane plus local orbital (LAPW+lo) method. The structural aspect of spinel oxides in cubic phase has been investigated by Perdew-Burke-Ernzerhof generalized gradient approximation (PBEsol-GGA). The thermodynamic stability of ABi2O4 is established by computing the cohesive energies. On ...

**Source: **Physics Letters A - March 8, 2019 **Category: **Physics **Source Type: **research

**Five-body choreography on the algebraic lemniscate is a potential motion**

Publication date: Available online 7 March 2019Source: Physics Letters AAuthor(s): Juan Carlos Lopez VieyraAbstractIn a remarkable paper of 2003 by Fujiwara et al. [1], a figure-eight three-body choreography on the algebraic lemniscate of Bernoulli was discovered. Such a choreography was found to be driven by the action of a pairwise potential V(rij), depending only on the mutual relative distances rij, i,j=1,2,3. In the present Letter we show that two different choreographies of five bodies on the same algebraic lemniscate exist and correspond to solutions of ten coupled Newton equations of motion with a pairwise interact...

**Source: **Physics Letters A - March 8, 2019 **Category: **Physics **Source Type: **research

**Insight into the magnetic behavior of Sr2IrO4: A spontaneous magnetization study**

Publication date: Available online 5 March 2019Source: Physics Letters AAuthor(s): Imtiaz Noor Bhatti, A.K. PramanikAbstractSr2IrO4 is a weak ferromagnet where the spin arrangement is canted anti-ferromagnetic (AF). Moreover, the spin-structure coupling plays an important role in magnetic behavior of Sr2IrO4. In this concern the magnetization under zero applied field i.e. spontaneous magnetization would be interesting to study and would give insight into the novel magnetic behavior of Sr2IrO4. Sophisticated techniques like neutron diffraction, μSR etc has been used to understand the magnetic behavior of Sr2IrO4 under ze...

**Source: **Physics Letters A - March 6, 2019 **Category: **Physics **Source Type: **research

**Electronic properties of the parabolic Dirac system**

Publication date: Available online 5 March 2019Source: Physics Letters AAuthor(s): Chen-Huan WuAbstractWe investigate the electronic properties of the parabolic Dirac system. In the presence of magnetic field, we discuss the thermodynamical potential and the anomalous diamagnetism due to the Dirac cone, and compared to the results of linear dispersion system. We found the local density of state peaks and the Landau levels are equidistant unlike the case of linear dispersion. The integer Hall conductivity and the intrinsic Hall conductivity induced by the Berry curvature are also investigated. Considering the disorder-induc...

**Source: **Physics Letters A - March 6, 2019 **Category: **Physics **Source Type: **research

**Highly sensitive selectively coated D-shape photonic crystal fibers for surface plasmon resonance sensing**

Publication date: Available online 5 March 2019Source: Physics Letters AAuthor(s): Fengning Zha, Jinsong Li, Pengjie Sun, Hongjie MaAbstractWe propose a design for a high sensitivity plasmon resonance (SPR) sensor based on photonic crystal fiber (PCF) and analyze the sensor using finite element software (FEM). By introducing a D-shape hole instead of a circular hole in the first ring of the photonic crystal fiber, which increases the coupling effect and proficient infiltration of the sensing, resulting in enhance the performance of the sensor due to the flat structure of the D-shape hole and the homogeneous metal coating f...

**Source: **Physics Letters A - March 6, 2019 **Category: **Physics **Source Type: **research

**Breather solutions of a negative order modified Korteweg-de Vries equation and its nonlinear stability**

Publication date: Available online 5 March 2019Source: Physics Letters AAuthor(s): Jingqun Wang, Lixin Tian, Yingnan ZhangAbstractThis paper is concerned with a negative order modified Korteweg-de Vries (nmKdV) equation which is in the negative flow of the mKdV hierarchy. We construct the breather solutions by Hirota's bilinear method and derive the infinite conservation laws through the Lax pair of the nmKdV equation. By constructing a new Lyapunov function with the conservation laws, we obtain the nonlinear stability of the breather solutions. (Source: Physics Letters A)

**Source: **Physics Letters A - March 6, 2019 **Category: **Physics **Source Type: **research

**Editors**

Publication date: 25 March 2019Source: Physics Letters A, Volume 383, Issue 11Author(s): (Source: Physics Letters A)

**Source: **Physics Letters A - March 6, 2019 **Category: **Physics **Source Type: **research

**Quantum heat switch with multiple qubits**

Publication date: Available online 4 March 2019Source: Physics Letters AAuthor(s): Marzie Jamshidi Farsani, Rosario FazioAbstractWe further elaborate on the device proposed by Karimi et al. [15], in which coupled superconducting qubits can play the role of a quantum heat switch. In the present paper we analyze the performances of the switch if the number of qubits increases considering in details the cases of three and four qubits. To this aim we study the effect of the number of qubits on the transmitted power between baths. As the number of qubits increases, the transmitted power between baths increases as well. (Source: Physics Letters A)

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

**Further investigation of mass dimension one fermionic duals**

Publication date: Available online 4 March 2019Source: Physics Letters AAuthor(s): J.M. Hoff da Silva, R.T. CavalcantiAbstractIn this paper we proceed into the next step of formalization of a consistent dual theory for mass dimension one spinors. This task is developed approaching the two different and complementary aspects of such duals, clarifying its algebraic structure and the so called τ−deformation. The former regards the mathematical equivalence of the recent proposed Lorentz preserving dual with the duals of algebraic spinors, from Clifford algebras, showing the consistency and generality of the new dual....

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

**Multiple-scale analysis of open quantum systems**

Publication date: Available online 5 March 2019Source: Physics Letters AAuthor(s): D.N. Bernal-García, B.A. Rodríguez, H. Vinck-PosadaAbstractIn this work, we present a multiple-scale perturbation technique suitable for the study of open quantum systems, which is easy to implement and in few iterative steps allows us to find excellent approximate solutions. For any time-local quantum master equation, whether markovian or non-markovian, in Lindblad form or not, we give a general procedure to construct analytical approximations to the corresponding dynamical map and, consequently, to the temporal evolution of t...

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

**THz radiation generation in axially magnetized collisional pair plasma**

Publication date: Available online 1 March 2019Source: Physics Letters AAuthor(s): Sheetal Punia, Hitendra K. MalikAbstractWe investigate the electron-positron plasma for terahertz radiation generation by two Dark Hollow Gaussian beams (DHGBs), which result in multifocal radiations quite useful for various modern applications. In this process, the ponderomotive force acts as a driver for the generation of terahertz field and the realistic situation of collisional plasma under the application of axial magnetic field reveals an efficient radiation generation. An appreciable efficiency of more than 2% is achieved for the proc...

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

**Robust bulk states**

Publication date: Available online 1 March 2019Source: Physics Letters AAuthor(s): C. YuceAbstractWe predict topologically robust zero energy bulk states in a disordered tight binding lattice. We explore a new kind of order and discuss that zero energy states exist in a system iff its Hamiltonian is noninvertible. We show that they are robust against any kind of disorder as long as the disordered Hamiltonian is noninvertible, too. (Source: Physics Letters A)

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

**Modeling the magnetocaloric effect of manganite using hybrid genetic and support vector regression algorithms**

Publication date: Available online 1 March 2019Source: Physics Letters AAuthor(s): Taoreed O. OwolabiAbstractLarge magnetocaloric effect demonstrated by manganite-based compounds has advanced the possibility of practical implementation of magnetic refrigeration technology. In order to enhance the magnetocaloric effect of manganite based compounds and to reduce the experimental stress involved in maximum magnetic entropy change (MMEC) determination, this work develops for the first time, hybrid genetic algorithm (GA) and support vector regression (SVR) models for estimating the MMEC, using the ionic radii and crystal lattic...

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

**Superior dielectric properties and bandgap modulation in hydrothermally grown Gr/MgO nanocomposite**

Publication date: Available online 1 March 2019Source: Physics Letters AAuthor(s): Richa Bhargava, Shakeel KhanAbstractMgO nanoparticles (NPs) and Gr/MgO nanocomposite (NC) have been synthesized by hydrothermal route. X-ray diffraction (XRD) analysis confirmed the crystalline cubic phase of MgO and Gr/MgO NC. Raman spectroscopy was used to study the defects in the NCs. Electron microscopy study display spherical NPs of MgO on graphene sheets. UV-visible spectroscopy shows a red shift in the absorption band and a significant reduction in the bandgap for Gr/MgO NC. The improvements in dielectric properties of NC can be ascri...

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

**Classicalization of quantum state of detector by amplification process**

Publication date: Available online 1 March 2019Source: Physics Letters AAuthor(s): Arash Tirandaz, Farhad Taher Ghahramani, Ali Asadian, Mehdi GolshaniAbstractIt has been shown that a macroscopic system being in a high-temperature thermal coherent state can be, in principle, driven into a non-classical state by coupling to a microscopic system. Therefore, thermal coherent states do not truly represent the classical limit of quantum description. Here, we study the classical limit of quantum state of a more relevant macroscopic system, namely the pointer of a detector, after the phase-preserving linear amplification process....

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

**Numerical parametric study of chiral effects and group delays in Ω element based terahertz metamaterial**

Publication date: Available online 28 February 2019Source: Physics Letters AAuthor(s): Danka B. Stojanović, Petra P. Beličev, Jelena Radovanović, Vitomir MilanovićAbstractIn this work, we have systematically studied the impact of geometric parameters on chiral effects which occur in metamaterial made of Ω elements. The analysis of group delays and electric field enhancements indicate stronger interaction between the structure and right circularly polarized waves. Calculations of optical activity and circular dichroism for different values of geometric parameters, allow us to deduce that the thickness of the wire ...

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

**Experimental detection of qubit-ququart pseudo-bound entanglement using three nuclear spins**

Publication date: Available online 28 February 2019Source: Physics Letters AAuthor(s): Amandeep Singh, Akanksha Gautam, Arvind, Kavita DoraiAbstractIn this work, we experimentally created and characterized a class of qubit-ququart PPT (positive under partial transpose) entangled states using three nuclear spins on an nuclear magnetic resonance (NMR) quantum information processor. Entanglement detection and characterization for systems with a Hilbert space dimension ≥2⊗3 is nontrivial since there are states in such systems which are both PPT as well as entangled. The experimental detection scheme that we devised f...

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

**A metal-semiconductor transition triggered by atomically flat zigzag edge in monolayer transition-metal dichalcogenides**

Publication date: Available online 28 February 2019Source: Physics Letters AAuthor(s): Yang Ni, Yan-Dong Guo, Xiao-Hong Yan, Hong-Li Zeng, Ying Zhang, Xin-Yu Chen, Xue-Yang ShenAbstractDue to the structure of three stacked layers, monolayer transition-metal dichalcogenides (TMDs) is different from graphene. Creating atomically flat graphene-like edges in them has long been expected, which is crucial to the modulation of electronic structures in two-dimensional systems. Recently, by thermal annealing, Chen et al. [21] successfully synthesized atomically flat Mo-terminated edge in monolayer MoS2. Inspired by this, through fi...

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

**Noise-induced quasiperiodicity in a ring of unidirectionally-coupled nonidentical maps**

Publication date: Available online 28 February 2019Source: Physics Letters AAuthor(s): A.N. Pisarchik, I.A. Bashkirtseva, L.B. RyashkoAbstractTransitions from equilibrium to quasiperiodicity and from a two-cycle to a quasiperiodic regime are studied in a ring of unidirectionally-coupled nonidentical logistic maps. The former scenario is realized through a “soft” (Neimark–Sacker) bifurcation, while the latter through a “hard” (saddle-node) bifurcation. Special attention is paid on a noise-induced transition through “hard” bifurcation, where a phenomenon of structural stabilization o...

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

**An improved Hirota bilinear method and new application for a nonlocal integrable complex modified Korteweg-de Vries (MKdV) equation**

Publication date: Available online 28 February 2019Source: Physics Letters AAuthor(s): Li Li, Chaonan Duan, Fajun YuAbstractThe Hirota bilinear method has been studied in a lot of local equations, but there are few of works to solve nonlocal equations by Hirota bilinear method. In this letter, we show that the nonlocal integrable complex modified Korteweg-de Vries (MKdV) equation admits multiple complex soliton solutions. A variety of exact solutions including the single bright soliton solutions and two bright soliton solutions are derived via constructing an improved Hirota bilinear method for nonlocal complex MKdV equati...

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

**Su-Schrieffer-Heeger model with imaginary gauge field**

Publication date: Available online 28 February 2019Source: Physics Letters AAuthor(s): Z. Oztas, N. CandemirAbstractWe consider Su-Schrieffer-Heeger (SSH) model in the presence of an imaginary gauge field. This model is non-Hermitian and has chiral symmetry. We investigate the influence of non-Hermiticity parameter on topologically trivial and nontrivial phases. We find topological edge states with real energy spectrum and obtain the topological invariant of the system. (Source: Physics Letters A)

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

**Acoustic measurements of the infinitesimal phase response curve from a sounding organ pipe**

Publication date: Available online 1 March 2019Source: Physics Letters AAuthor(s): Masahiro Okada, Tokihiko Kaburagi, Isao T. TokudaAbstractThe infinitesimal phase response curve (iPRC) of an organ pipe was measured using two types of external forcing, namely, sinusoidal and pulse forcing. Although the measured iPRCs exhibited different shapes because of the difficulty in realizing ideal pulses in acoustic experiments, the spectral structures agreed between both methods. Both measurements indicated that an external sound, which matched the pipe's second resonance, could most effectively induce frequency locking. Acoustical...

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

**Energy exchange between discrete breathers in graphane in thermal equilibrium**

Publication date: Available online 27 February 2019Source: Physics Letters AAuthor(s): K.A. Krylova, J.A. Baimova, R.T. Murzaev, R.R. MulyukovAbstractGraphane is a fully hydrogenated graphene which is practically interesting for application in electronics, hydrogen storage and transportation, in nanoscale devices. As it was previously shown, the energy of a discrete breather (nonlinear localised mode) in graphane close to the value of the energy barrier at which the dehydrogenation of graphene occurs. In the present work, molecular dynamics simulation is used to investigate the possibility of energy exchange between discre...

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

**State Observer for Stochastic Resonance in Bistable System**

Publication date: Available online 27 February 2019Source: Physics Letters AAuthor(s): Jinming Liu, Jian Mao, Bin Huang, Peiguo LiuAbstractWe investigate numerically stochastic resonance variation in bistable system. Putting signals with different intensities into a bistable system, or adjusting system structural parameters for an input, will produce different motion trajectories. These trajectories contain both chaos and non-chaos parts. We classify these states according to the state of resonance and chaos, and propose a state observer. In this way, bistable system becomes an observable nonlinear system. State observer c...

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

**Analytical derivation of the impulse response for the bounded 2-D diffusion channel**

Publication date: Available online 26 February 2019Source: Physics Letters AAuthor(s): Fatih Dinc, Bayram Cevdet Akdeniz, Ecda Erol, Dilara Gokay, Ezgi Tekgul, Ali Emre Pusane, Tuna TugcuAbstractThis letter focuses on the derivation of the hitting probabilities of diffusing particles absorbed by an agent in a bounded environment. In particular, we analogously consider the impulse response of a molecular communication channel in a 2-D and 3-D environment. In 2-D, the channel involves a point transmitter that releases molecules to a circular absorbing receiver that absorbs incoming molecules in an environment surrounded by a...

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