**Boron and nitrogen co-doped graphene nanosheets for NO and NO2 gas sensing**

Publication date: Available online 20 February 2019Source: Physics Letters AAuthor(s): Mehdi D. EsrafiliAbstractUsing dispersion-corrected density functional theory calculations, the adsorption behavior of NO and NO2 molecules is studied over B-doped and BN co-doped graphene sheets (BCmNn-Gr; m,n=0,1,2,3 and m+n=3). To examine practical gas sensing application and selectivity, the adsorption of H2O, CO and CO2 molecules is also studied on the BCmNn-Gr surfaces. It is found that the preferred adsorption site for the adsorption of these molecules is above the B atom due to accumulation of a local positive charge. Meanwhile, ...

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

**Effects of sm substitution on ferroelectric domains and conductivity in bismuth ferrite ceramics**

Publication date: Available online 20 February 2019Source: Physics Letters AAuthor(s): Panithan Sriboriboon, Benjaporn Yotburut, Oradee Srikimkaew, Sartanee Suebka, Arreerat Jiamprasertboon, Santi Maensiri, Worasom KundhikanjanaAbstractThe large piezoelectric coefficient and multiferroicity of bismuth ferrite (BFO) make it an attractive candidate for lead-free ferroelectric devices. However, large leakage currents have limited broader applications. Rare-earth substitutions in BFO have been shown to improve ferroelectric and magnetic properties. In this work, we employed piezoresponse and conductive atomic force microscopy ...

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

**Global dynamics of a pipe conveying pulsating fluid in primary parametrical resonance: Analytical and numerical results from the nonlinear wave equation**

Publication date: Available online 20 February 2019Source: Physics Letters AAuthor(s): Qiliang Wu, Guoyuan QiAbstractThe chaotic dynamics of nonlinear waves in the harmonic-forced fluid-conveying pipe in primary parametrical resonance, is explored analytically and numerically. The multiple scale method is applied to obtain an equivalent nonlinear wave equation from the complicated nonlinear governing equation describing the fluid conveyed in a pipe. With the Melnikov method, the persistence of a heteroclinic structure is shown to be satisfied and its condition is given in functional form. Similarly, for the heteroclinic or...

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

**Erratum to “Harmonic balancing approach to nonlinear oscillations of a punctual charge in the electric field of charged ring” [Phys. Lett. A 373 (7) (2009) 735–740]**

Publication date: Available online 19 February 2019Source: Physics Letters AAuthor(s): Augusto Beléndez, Klaus R. Schneider (Source: Physics Letters A)

**Source: **Physics Letters A - February 20, 2019 **Category: **Physics **Source Type: **research

**Integrated Experimental and Computational Approach for Nanoparticle Flow Analysis**

We report a new method combining computational fluid dynamics and flow experiments with customized channels to understand the transport of nanoparticles. Iron oxide nanoparticles, being highly attractive for biomedical research are chosen as model nanoparticles for the transport studies. Four different polyvinyl pyrrolidone and polyethyleneimine coated iron oxide nanoparticles of hydrodynamic sizes ranging from 45 – 178 nm were synthesized. These nanoparticles were adjusted to different target mass concentrations and ran through a bent tube to determine flow velocity and mass loss, specific to the nanoparticles. Comp...

**Source: **Physics Letters A - February 20, 2019 **Category: **Physics **Source Type: **research

**Large negative differential resistance behavior in arsenene nanoribbons induced by vacant defects**

Publication date: Available online 19 February 2019Source: Physics Letters AAuthor(s): Wei-Hua Xiao, Fang Xie, Xiao-Jiao Zhang, Yu-Fang Chu, Jian-Ping Liu, Hai-Yan Wang, Zhi-Qiang Fan, Meng-Qiu Long, Ke-Qiu ChenAbstractWe have studied the electronic structures of arsenene nanoribbons with different edge passivations by employing first-principle calculations. Furthermore, the effects of the defect in different positions on the transport properties of arsenene nanoribbons are also investigated. We find that the band structures of arsenene nanoribbons are sensitive to the edge passivation. The current-voltage characteristics ...

**Source: **Physics Letters A - February 20, 2019 **Category: **Physics **Source Type: **research

**Editors**

Publication date: 28 February 2019Source: Physics Letters A, Volume 383, Issue 9Author(s): (Source: Physics Letters A)

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

**Ab initio study of the effect of thickness and epitaxial strain on the magnetic structure of NiMn freestanding films**

Publication date: Available online 13 February 2019Source: Physics Letters AAuthor(s): Masoud Rahbar Niazi, Sohrab Sanjabi, Yousef JamaliAbstractThe magnetic properties of tetragonal structure of stoichiometric NiMn alloy is investigated using density functional theory within the local spin density approximation. The system studied here, is a free standing film. The effect of thickness and epitaxial strain on the magnetic and structural properties is examined. It is found that while the magnetic moments of Mn surface atoms vary depending on the number of layers being odd (3.60 μB) or even (3.55 μB) the magnitude of t...

**Source: **Physics Letters A - February 14, 2019 **Category: **Physics **Source Type: **research

**Optimum adaptive array stochastic resonance in noisy grayscale image restoration**

Publication date: Available online 13 February 2019Source: Physics Letters AAuthor(s): Jian Liu, Bing Hu, Youguo WangAbstractConsidering the widespread noise interference in the two-dimensional (2D) image transmission processing, we proposed an optimal adaptive bistable array stochastic resonance (SR)-based grayscale image restoration enhancement method under low peak signal-to-noise ratio (PSNR) environments. In this method, the Hilbert scanning is adopted to reduce the dimension of the original grayscale image. The 2D image signal is converted into a one-dimensional (1D) binary pulse amplitude modulation (BPAM) signal. M...

**Source: **Physics Letters A - February 14, 2019 **Category: **Physics **Source Type: **research

**Structural, optoelectronic and thermoelectric properties of antiperovskite compounds Ae3PbS (Ae = Ca, Sr and Ba): A first principles study**

Publication date: Available online 12 February 2019Source: Physics Letters AAuthor(s): D.M. HoatAbstractIn the last years, alkaline-earth based antiperovskite compounds with small semiconductor band gap have been proven to be promising candidate for optoelectronic and thermoelectric applications. In this work, the structural, electronic, optical and thermoelectric properties of Ae3PbS (Ae = Ca, Sr and Ba) compounds have been predicted using first principles calculations based on the full-potential linearized augmented plane-wave (FP-LAPW) method and semiclassical Boltzmann transport theory. Exchange-correlation effect is t...

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

**Interactions between vortex and magnetic rings at high kinetic and magnetic Reynolds numbers**

Publication date: Available online 12 February 2019Source: Physics Letters AAuthor(s): Demosthenes KivotidesAbstractInteractions between magnetic and vortex rings are studied over a wide interval of interaction parameter values ranging from negligible magnetic effects on vorticity structure, to very strong effects. The employed interaction parameter measures the strength of the Lorentz force in units of the inertial force. At small interaction parameters, the vortex ring shapes part of the magnetic ring into a dissipative, curved, magnetic sheet structure. At high interaction parameters, the Lorentz force acts as an agent ...

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

**Periodic Néel skyrmion transport**

Publication date: Available online 13 February 2019Source: Physics Letters AAuthor(s): L. Resse, L.G.S. Oliveira, C.I.L. de Araujo, A.R. Pereira, R.L. SilvaAbstractIn this work, we have used the MuMax3 software to simulate devices consisting of a ferromagnetic thin film placed over a heavy metal thin film. The devices are two interconnected partial-disks where a Néel domain wall is formed in the disks junction. In our simulations we investigate devices with disk radius r=50 nm and different distance d between the disks centers (from d=12 nm to d=2R=100 nm). By applying strong sinusoidal external magnetic fields, we ...

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

**Interface induced exchange bias effect in La0.67Sr0.33MnO3/SrIrO3 multilayer**

Publication date: Available online 11 February 2019Source: Physics Letters AAuthor(s): Rachna Chaurasia, K.C. Kharkwal, A.K. PramanikAbstractEpitaxial superlattices of ferromagnetic/paramagnetic La0.67Sr0.33MnO3/SrIrO3 materials have been prepared on SrTiO3 (100) substrate using pulse laser deposition technique. An unexpected onset of interface magnetic interaction has been observed around 40 K. Interestingly, magnetic exchange bias effect has been observed in both field cooled and zero field cooled magnetization loops, however, the shifting of loop is opposite in both measurements. Exchange bias field vanishes as temperat...

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

**Exploring new insights in BAlN from evolutionary algorithms ab initio computations**

Publication date: Available online 7 February 2019Source: Physics Letters AAuthor(s): H. Maiz Hadj Ahmed, H. Benaissa, A. Zaoui, M. FerhatAbstractBN-AlN alloys are potential candidates to achieve wide band gap material for ultraviolet device applications. By combing density functional theory and evolutionary structure predictions, we systematically explore the thermodynamic, mechanical, dynamical and optical properties of BxAl1−xN alloys. Through structure search, three compounds (cubic (BAl3N4, and B3AlN4, space group P-43m), and tetragonal (BAlN2, space group P-42m)) have been predicted. The calculated relative lar...

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

**Plasmon enhanced light trapping in thin film GaAs solar cells by Al nanoparticle array**

Publication date: Available online 6 February 2019Source: Physics Letters AAuthor(s): Gurjit Singh, S.S. VermaAbstractLight trapping is a crucial factor to enhance the performance of thin film solar cells. For effective light trapping, we introduced Al nanoparticle array on the top and rear surface of thin film GaAs solar cells. The effect of both array on the optical absorption and current density of solar cells is investigated by using finite difference time domain (FDTD) method. The optimization process of top and rear array in solar cells is done systematically. The results indicate that by plasmonic action of arrays, ...

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

**An alternative form of Hooge's relation for 1/f noise in semiconductor materials**

Publication date: Available online 6 February 2019Source: Physics Letters AAuthor(s): Ferdinand GrüneisAbstractSingle quantum dots and other materials exhibit irregular switching between on and off states; these on-off states follow power-law statistics giving rise to 1/f noise. We transfer this phenomenon (also referred to as on-off intermittency) to the generation and recombination (= g–r) process in semiconductor materials. In addition to g–r noise we obtain 1/f noise that can be provided in the form of Hooge's relation. The predicted Hooge coefficient is αH=αXαim whereby αX depe...

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

**Ballistic thermal transport in black and blue phosphorene nanoribbons and in-plane heterostructures**

Publication date: Available online 7 February 2019Source: Physics Letters AAuthor(s): Wei Cao, Huaping Xiao, Tao Ouyang, Ziyu Wang, Rui XiongAbstractThe thermal transport properties of black and blue phosphorene nanoribbons and in-plane heterostructures are systematically investigated by non-equilibrium Green's-function method. Both edge shape and width have a sensitive influence on the thermal conductance of pristine black and blue phosphorene nanoribbons and they all exhibit a clear anisotropic thermal performance. Interestingly, the in-plane heterostructures possess a tunable thermal conductance which depends on the per...

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

**Dynamical analysis of a new multistable chaotic system with hidden attractor: Antimonotonicity, coexisting multiple attractors, and offset boosting**

Publication date: Available online 5 February 2019Source: Physics Letters AAuthor(s): Atiyeh Bayani, Karthikeyan Rajagopal, Abdul Jalil M. Khalaf, Sajad Jafari, G.D. Leutcho, J. KengneAbstractAnalyzing chaotic systems with coexisting and hidden attractors has been receiving much attention recently. In this article, we analyze a four dimensional chaotic system which has a plane as the equilibrium points. Also this system is of the group of systems that have coexisting attractors. First, the system is introduced and then stability analysis, bifurcation diagram and Largest Lyapunov exponent of this system are presented as met...

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

**Modes conversion due to plasmons induced transparency**

Publication date: Available online 5 February 2019Source: Physics Letters AAuthor(s): Wanxia Huang, Chaogang Li, Maosheng Wang, Yong Zhou, Cunyuan Zhu, Kuanguo Li, Xinyan Yang, Fabao ZhangAbstractWe investigate simulated and theoretically the optical properties of the metamaterial, composed of two bigger split ring resonators and one smaller split ring resonator in unit cell. We observe the magic phenomena that one mode B is inhibited from strong to weak then disappears while another mode A appears and becomes stronger and stronger as asymmetric degree increases. The results show the mode A originates from the destructive ...

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

**Levitation of a Rapidly Oscillating Magnetic Dipole Above a Metallic Sheet**

Publication date: Available online 5 February 2019Source: Physics Letters AAuthor(s): B. ShayakAbstractWe show that such a magnetic dipole suspended at a height h above a conducting sheet experiences a lift force proportional to 1/h2. This represents an order of magnitude improvement over the 1/h4 lift obtained in the quasistatic limit. (Source: Physics Letters A)

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

**Effective equation for quasi-one dimensional tube-shaped Bose–Einstein condensates**

Publication date: Available online 5 February 2019Source: Physics Letters AAuthor(s): Mateus C.P. dos Santos, Wesley B. CardosoAbstractIn this letter we derive an effective 1D equation that describes the axial dynamics of a tube-shaped Bose–Einstein condensate. The dimensional reduction is achieved by using a variational approach starting from the 3D Gross–Pitaevskii equation (GPE) in presence of a nonharmonic external potential in the transverse direction and generic in the axial one. The resulting equation is a time-dependent 1D nonpolynomial Schrödinger equation (NPSE). In view to check the accuracy of ...

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

**Study of a dynamical system with a strange attractor and invariant tori**

Publication date: Available online 5 February 2019Source: Physics Letters AAuthor(s): Antonio Algaba, Manuel Merino, Bowei Qin, Alejandro J. Rodríguez-LuisAbstractA simple three-dimensional time-reversible system of ODEs with quadratic nonlinearities is considered in a recent paper Sprott (2014) [37]. The author finds in this system, that has no equilibria, the coexistence of a strange attractor and invariant tori. The goal of this letter is to justify theoretically the existence of infinite invariant tori and chaotic attractors. For this purpose we embed the original system in a one-parameter family of reversible s...

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

**Modeling complex networks with accelerating growth and aging effect**

Publication date: Available online 5 February 2019Source: Physics Letters AAuthor(s): Jin Liu, Jian Li, Chen Yadang, Xianyi Chen, Zhili Zhou, Zejun Yang, Cheng-Jun ZhangAbstractNumerous empirical studies have revealed that a large number of real networks exhibit the property of accelerating growth, i.e. network size (nodes) increases superlinearly with time. Examples include the size of social networks, the output of scientists, the population of cities, and so on. In the literature, these real systems are widely represented by complex networks for analysis, and many network models have been proposed to explain the observe...

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

**Hole-Polarons and Bipolarons in the Holstein t − J model: Relevance of Inter-site Hole-phonon Interaction**

Publication date: Available online 6 February 2019Source: Physics Letters AAuthor(s): Krishanu Roy, Subhadip Nath, Kumar GhoshAbstractThe interaction of the doped holes with lattice vibrations in an antiferromagnetic (AF) background is studied using the t−J-Holstein model on an 8-site cluster with 2-holes by an exact method. The phonon mediated interactions between the holes at nearest-neighbor (NN) sites are considered. We have calculated the effective kinetic energy, hole-phonon and hole-hole correlations, two hole binding energy to study the nature and stability of various quasiparticles. At negligible to very wea...

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

**Ground-state phase diagram of the 1-D Holstein–Hubbard model**

Publication date: Available online 5 February 2019Source: Physics Letters AAuthor(s): M. Zahid Malik, Soma Mukhopadhyay, Ashok ChatterjeeAbstractThe Holstein–Hubbard model is investigated in one-dimension at half filling employing a series of unitary transformations taking into account the coherence and correlation of phonons. To treat the phonon subsystem more accurately a new squeezing transformation is introduced to incorporate the electron-density-dependent onsite phonon correlations to lower the energy further. The effective electronic Hamiltonian is next obtained by averaging the transformed Hamiltonian with re...

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

**A steady state quantum classifier**

We report that under some specific conditions a single qubit model weakly interacting with information environments can be referred to as a quantum classifier. We exploit the additivity and the divisibility properties of the completely positive (CP) quantum dynamical maps in order to obtain an open quantum classifier. The steady state response of the system with respect to the input parameters was numerically investigated and it's found that the response of the open quantum dynamics at steady state acts non-linearly with respect to the input data parameters. We also demonstrate the linear separation of the quantum data ins...

**Source: **Physics Letters A - February 2, 2019 **Category: **Physics **Source Type: **research

**Designing a broad locally-resonant bandgap in a phononic crystals**

This study opens new possibilities to broaden locally-resonant bandgaps of phononic crystals for low frequencies. The results can potentially be used to reduce vibration and noise in many applications. (Source: Physics Letters A)

**Source: **Physics Letters A - February 2, 2019 **Category: **Physics **Source Type: **research

**The 2D Kramers–Dirac oscillator**

Publication date: Available online 1 February 2019Source: Physics Letters AAuthor(s): T. Iwai, B. ZhilinskiiAbstractThe Dirac oscillator was initially introduced as a Dirac operator which is linear in momentum and coordinate variables. In contrast to the usual 2D Dirac oscillator, the 2D Kramers–Dirac oscillator admits the time-reversal symmetry, which is a reason for the present nomenclature. It is shown that there exists a family of eigenstates associated with an eigenvalue linear in the control parameter, and the eigenvalue in question goes down from positive values to negative values as the parameter varies in th...

**Source: **Physics Letters A - February 2, 2019 **Category: **Physics **Source Type: **research

**Electronic and optical properties of van der Waals vertical heterostructures based on two-dimensional transition metal dichalcogenides: First-principles calculations**

Publication date: Available online 1 February 2019Source: Physics Letters AAuthor(s): Kai Ren, Minglei Sun, Yi Luo, Sake Wang, Yujing Xu, Jin Yu, Wencheng TangAbstractFour vertical heterostructures based on two-dimensional transition-metal dichalcogenides (TMDs) – MoS2/GeC, MoSe2/GeC, WS2/GeC, and WSe2/GeC, were studied by density functional theory calculations to investigate their structure, electronic characteristics, principle of photogenerated electron–hole separation, and optical-absorption capability. The optimized heterostructures were formed by van der Waals (vdW) forces and without covalent bonding. Th...

**Source: **Physics Letters A - February 2, 2019 **Category: **Physics **Source Type: **research

**Pressure-dependent photoluminescence of CdSe/ZnS quantum dots: critical point of different pressure regimes**

Publication date: Available online 1 February 2019Source: Physics Letters AAuthor(s): Bo Li, Weilong Liu, Xiaojun Zhu, Shan Lin, Yanqiang Yang, Qingxin Yang, Peng JinAbstractHigh pressure condition can alter and control the electronic structure of semiconductor quantum dots, and therefore provides novel insight for designing optoelectronic devices. Here we report the pressure-dependent photoluminescence (PL) of CdSe/ZnS core/shell quantum dots (QD) in different pressure regimes. The center of the PL spectrum has blue-shift when hydrostatic pressure increases, due to the increasing bulk modulus. However, the shifting rate b...

**Source: **Physics Letters A - February 2, 2019 **Category: **Physics **Source Type: **research

**The fate of self-aligned rolls in gravity modulated magnetoconvection**

Publication date: Available online 31 January 2019Source: Physics Letters AAuthor(s): Arnab BasakAbstractWe explore the modifications brought about by gravity modulation in self-aligned two-dimensional (2D) stationary rolls and higher-order convective instabilities with horizontal magnetic field. The Chandrasekhar number plays no role in determining critical values of the forcing parameters for convection to begin. The onset is in the form of 2D rolls with periodically varying intensity. The external magnetic field is solely responsible for aligning the rolls while the induced magnetic field comes into play after three-dim...

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

**High-performance refractive index sensor based on guided-mode resonance in all-dielectric nano-silt array**

Publication date: Available online 30 January 2019Source: Physics Letters AAuthor(s): Guilian Lan, Song Zhang, Hong Zhang, Yuhang Zhu, Longyu Qing, Daimin Li, Jinpeng Nong, Wei Wang, Li Chen, Wei WeiAbstractWe propose a high-quality refractive index sensing by utilizing the characteristic guided-mode resonance (GMR) excited in a simple one-dimensional all-dielectric nano-slit array. We demonstrate a figure of merit up to 12000, which is higher than that achieved in most plasmonic refractive index sensors. We show that high-quality sensing performance can be sustained over a broadband range in near infrared region with rela...

**Source: **Physics Letters A - January 31, 2019 **Category: **Physics **Source Type: **research

**Editors**

Publication date: 11 February 2019Source: Physics Letters A, Volume 383, Issue 8Author(s): (Source: Physics Letters A)

**Source: **Physics Letters A - January 31, 2019 **Category: **Physics **Source Type: **research

**Interaction of Love waves with coupled cavity modes in a 2D holey phononic crystal**

Publication date: Available online 29 January 2019Source: Physics Letters AAuthor(s): Yuxin Liu, Abdelkrim Talbi, Bahram Djafari-Rouhani, El Houssaine El Boudouti, Lucie Drbohlavová, Vincent Mortet, Olivier Bou Matar, Philippe PernodAbstractThe interaction of Love waves with square array of pillars deposited on a cavity defined in a 2D holey phononic crystal is numerically investigated using Finite Element Method. First, the existence of SH surface modes is demonstrated separately for phononic crystals that consist of square arrayed holes, or rectangular arrayed Ni pillars, respectively in, or on, a SiO2 film deposi...

**Source: **Physics Letters A - January 30, 2019 **Category: **Physics **Source Type: **research

**The synchronization method for fractional-order hyperchaotic systems**

Publication date: Available online 29 January 2019Source: Physics Letters AAuthor(s): Dali Feng, Hongli An, Haixing Zhu, Yunfeng ZhaoAbstractIn this paper, a function cascade synchronization method for fractional-order hyperchaotic systems is introduced to achieve the synchronization of two identical fractional-order hyperchaotic systems. It is shown that the method is not only theoretically rigorous, practically feasible, but also a more general one, which contains the complete synchronization, modified projective synchronization and anti-phase synchronization. In order to valid the effectiveness of the proposed method, w...

**Source: **Physics Letters A - January 30, 2019 **Category: **Physics **Source Type: **research

**Quantum topological transitions and spinons in metallic ferro- and antiferromagnets**

Publication date: Available online 29 January 2019Source: Physics Letters AAuthor(s): V.Yu. IrkhinAbstractAn effective Hamiltonian describing fluctuation effects in the magnetic phases of the Hubbard model in terms of spinon excitations is derived. A comparison of spin-rotational Kotliar–Ruckenstein slave boson and Ribeiro–Wen dopon representations is performed. The quantum transition into the half-metallic ferromagnetic state with vanishing of spin-down Fermi surface is treated as the topological Lifshitz transition in the quasimomentum space. The itinerant-localized magnetism transitions and Mott transition i...

**Source: **Physics Letters A - January 30, 2019 **Category: **Physics **Source Type: **research

**Fluxon interaction with the finite-size dipole impurity**

Publication date: Available online 29 January 2019Source: Physics Letters AAuthor(s): Ivan O. Starodub, Yaroslav ZolotaryukAbstractInteraction of the fluxon with the finite size dipole impurity in the long Josephson junction is investigated. The impurity has polarity and will be referred to as a dipole impurity because it also has a direction and, consequently, changes its sign under the space inversion transform x→−x. Such a model is used to describe the inductively coupled to the Josephson transmission line qubit and the misaligned Abrikosov vortex that penetrates into the long Josephson junction. We derive th...

**Source: **Physics Letters A - January 30, 2019 **Category: **Physics **Source Type: **research

**Intrinsic edge warping of graphene nanoribbon boost molecular directional motion: Toward the novel nanodevices**

Publication date: Available online 29 January 2019Source: Physics Letters AAuthor(s): Yafei Wang, Changguo Wang, Huifeng TanAbstractIn this letter, nanodirectional motion due to intrinsic warping edge of graphene nanoribbon is demonstrated using theoretical analysis and molecular dynamics (MD) simulation. Simulation model is established and the underlying physical insights of intrinsic nanodirectional motion are investigated. It is found that nanodirectional motion of carbon fullerene is gradient-dependent. Directional motion with +z-warping graphene edge is energetically favorable over the −z-warping configuration. ...

**Source: **Physics Letters A - January 30, 2019 **Category: **Physics **Source Type: **research

**Finite temperature aspect ratio in ultra-cold Bose gas for large N**

We present a detailed study of the temperature dependence of the condensate fraction, collective excitation and aspect ratio profiles of a Bose-condensed gas in a harmonic trap for large numbers of condensate atoms up to 85000. These quantities are calculated self-consistently using the generalized Hartree–Fock–Bogoliubov (GHFB) equations. We determine the evolution of the aspect ratio at zero and finite temperature via the condensed fraction. We compare our results with experimental data and we find a good agreement. (Source: Physics Letters A)

**Source: **Physics Letters A - January 29, 2019 **Category: **Physics **Source Type: **research

**CN-Smorodinsky–Winternitz system in a constant magnetic field**

Publication date: Available online 28 January 2019Source: Physics Letters AAuthor(s): Hovhannes ShmavonyanAbstractWe propose the superintegrable generalization of Smorodinsky–Winternitz system on the N-dimensional complex Euclidian space which is specified by the presence of constant magnetic field. We find out that in addition to 2N Liouville integrals the system has additional functionally independent constants of motion, and compute their symmetry algebra. We perform the Kustaanheimo–Stiefel transformation of C2-Smorodinsky–Winternitz system to the (three-dimensional) generalized MICZ-Kepler problem an...

**Source: **Physics Letters A - January 29, 2019 **Category: **Physics **Source Type: **research

**Effects of built-in electric field on donor binding energy in InGaN/ZnSnN2 quantum well structures**

Publication date: Available online 28 January 2019Source: Physics Letters AAuthor(s): Hasan YıldırımAbstractInxGa1−xN/ZnSnN2 quantum well structures are studied in terms of a binding energy of a donor atom. 1s and 2p± impurity states are considered. The Schrödinger's and Poisson's equations are solved self-consistently. A hydrogenic type wave function to represent each impurity state is assumed. The calculations include band-bending in the potential energy profile introduced by the built-in electric field existing along the structures. The binding energy and the energy of the transition between the imp...

**Source: **Physics Letters A - January 29, 2019 **Category: **Physics **Source Type: **research

**Chiral anomaly in Weyl systems: No violation of classical conservation laws**

Publication date: Available online 28 January 2019Source: Physics Letters AAuthor(s): K. MorawetzAbstractThe anomalous term ∼EB in the balance of the chiral density can be rewritten as quantum current in the classical balance of density. Therefore it does not violate conservation laws as sometimes claimed to be caused by quantum fluctuations. (Source: Physics Letters A)

**Source: **Physics Letters A - January 29, 2019 **Category: **Physics **Source Type: **research

**Justification of the discrete nonlinear Schrödinger equation from a parametrically driven damped nonlinear Klein–Gordon equation and numerical comparisons**

Publication date: Available online 28 January 2019Source: Physics Letters AAuthor(s): Y. Muda, F.T. Akbar, R. Kusdiantara, B.E. Gunara, H. SusantoAbstractWe consider a damped, parametrically driven discrete nonlinear Klein–Gordon equation, that models coupled pendula and micromechanical arrays, among others. To study the equation, one usually uses a small-amplitude wave ansatz, that reduces the equation into a discrete nonlinear Schrödinger equation with damping and parametric drive. Here, we justify the approximation by looking for the error bound with the method of energy estimates. Furthermore, we prove the l...

**Source: **Physics Letters A - January 29, 2019 **Category: **Physics **Source Type: **research

**Energy gaps and half-metallicity in β-graphyne nanoribbons**

Publication date: Available online 29 January 2019Source: Physics Letters AAuthor(s): Yan-Qing Liu, Lei Xu, Jun ZhangAbstractWe investigate the energy gaps and half-metallicity of the zigzag-edged β-graphyne nanoribbons via a tight-binding approach. In the presence of on-site Coulomb repulsion and proper transverse electric field strengths, the nanoribbons are forced into a half-metallic state by the electric field. A phase transition from half-metal to insulator is realized by changing the electric field or Coulomb potential. Both the electric field and Coulomb repulsion can open direct band gaps, resulting in a meta...

**Source: **Physics Letters A - January 29, 2019 **Category: **Physics **Source Type: **research

**On the weakly-bound (1,1)-states in the three-body ddμ and dtμ muonic ions**

Publication date: Available online 29 January 2019Source: Physics Letters AAuthor(s): Alexei M. FrolovAbstractThe both total and binding energies of the (1,1)-states in the weakly-bound three-body muonic ddμ and dtμ ions are determined to high numerical accuracy. The binding energy of the (1,1)-state in the muonic dtμ ion is evaluated as ε(dtμ)=−0.66033003831(30)eV, while for the same state in the muonic ddμ ion we have found that ε(ddμ)=−1.9749806166970(30)eV. These energies are the most accurate numerical values obtained for these systems and they are sufficient for all curre...

**Source: **Physics Letters A - January 29, 2019 **Category: **Physics **Source Type: **research

**Lump-soliton solutions to the Fokas system**

Publication date: Available online 25 January 2019Source: Physics Letters AAuthor(s): Jiguang Rao, Dumitru Mihalache, Yi Cheng, Jingsong HeAbstractIn this letter, we obtain families of semi-rational solutions termed lump-soliton solutions to the Fokas system by using the Hirota's bilinear method combined with the Kadomtsev-Petviashvili (KP) hierarchy reduction method. These exact semi-rational solutions illustrate the collision of lumps and dark-line solitons. Two different types of evolution scenarios occur: (a) fusion of lumps and dark-line solitons into dark-line solitons, and (b) fission of dark-line solitons into lump...

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

**Delay of terminal current in systems with abruptly changed Hamiltonian**

Publication date: Available online 24 January 2019Source: Physics Letters AAuthor(s): Mou Yang, Xian-Jin Ran, Bo Su, Rui-Qiang WangAbstractThe current response for the parameter change of a mesoscopic system is a practical issue for future's circuit design. Nowadays most considered cases are varied types of bias modulation, while the effect of change of conductor Hamiltonian is seldom addressed. In this paper, we investigate the response of ballistic transport induced by a sudden change of the conductor Hamiltonian. We formulize the terminal current in language of non-equilibrium Green's function. Our method is applied to ...

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

**Plasmon modes in MLG-2DEG heterostructures: Temperature effects**

Publication date: Available online 24 January 2019Source: Physics Letters AAuthor(s): Nguyen Van Men, Nguyen Quoc Khanh, Dong Thi Kim PhuongAbstractWe calculate the plasmon frequency and damping rate in a double-layer system made of monolayer graphene and GaAs quantum well at finite temperature using the random-phase-approximation dielectric function and taking into account the inhomogeneity of the dielectric background of the system. We show that the temperature, interlayer correlation parameters and dielectric background inhomogeneity affect significantly the plasmon frequencies and damping rates of the system. At low te...

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

**Investigating the nonequilibrium aspects of long-range Potts model: Refinement of critical temperatures and raw exponents**

Publication date: Available online 25 January 2019Source: Physics Letters AAuthor(s): Roberto da Silva, J.R. Drugowich de Felicio, Henrique A. FernandesAbstractIn this work, we analyse the q−state Potts model with long-range interactions through nonequilibrium scaling relations commonly used when studying short-range systems. We determine the critical temperature via an optimization method for short-time Monte Carlo simulations. The study takes into consideration two different boundary conditions and three different values of range parameters of the couplings. We also present estimates of some critical exponents, nam...

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

**Noise-induced multilevel Landau–Zener transitions: Density matrix investigation**

Publication date: Available online 21 January 2019Source: Physics Letters AAuthor(s): I.F. Nyisomeh, M.E. Ateuafack, L.C. FaiAbstractThe generalised multilevel Landau–Zener problem is solved by applying the density matrix technique within the framework of nonstationary perturbation theory. The exact survival probability is achieved as a proof of the Brundobler–Elzer hypothesis (Brundobler and Elzer (1993) [38]). The effect of classical Gaussian noise is investigated by averaging the solution over the noise realisation. A generalised formula for slow noise-induced transition probability is obtained and found to ...

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