**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

**A quantummechanical derivation of the eigenvalues of the quadratic Casimir operator of the algebra SU(n) in Young tableau representation**

Publication date: Available online 22 January 2019Source: Physics Letters AAuthor(s): Éva SzőkeAbstractThe paper concerns the eigenvalues and eigenfunctions of the quadratic Casimir operator of the algebra SU(n) in the Young tableau representation. Our starting point is a concrete physical problem in second quantized formalism. We use quantummechanical and group theoretical vehicles to determine the aimed quantities. The tableaux are organized according to their eigenvalue. We also investigate the modification rules. (Source: Physics Letters A)

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

**Introduction in the band theory of molten salts**

Publication date: Available online 22 January 2019Source: Physics Letters AAuthor(s): Alexander L. ShimkevichAbstractThe electrochemical properties of molten salts are considered in the frame of band theory for ideal crystalline dielectrics. It turned out that metal impurities at low concentration in them generate the local electron levels in the wide band gap (>4 eV) of molten salt divided by 50 meV and more. They are occupied by electrons when Fermi level is approached to them from below. Then, the minor metal impurities fall out the molten salt when the electron occupation of their energy levels in the band gap achie...

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

**Comparison of diluted antiferromagnetic Ising models on frustrated lattices in a magnetic field**

Publication date: Available online 22 January 2019Source: Physics Letters AAuthor(s): Konstantin Soldatov, Alexey Peretyatko, Petr Andriushchenko, Konstantin Nefedev, Yutaka OkabeAbstractWe study diluted antiferromagnetic Ising models on triangular and kagome lattices in a magnetic field, using the replica-exchange Monte Carlo method. We observe seven and five plateaus in the magnetization curve of the diluted antiferromagnetic Ising model on the triangular and kagome lattices, respectively, when a magnetic field is applied. These observations contrast with the two plateaus observed in the pure model. The origin of multipl...

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

**Cooperative activation effect on H2O adsorption in MnO–Co catalyzed steam methane reforming**

Publication date: Available online 22 January 2019Source: Physics Letters AAuthor(s): Zhaoming Fu, Meng Liu, Qian Sun, Dongwei Ma, Zongxian YangAbstractSteam methane reforming is a very important chemical process in hydrogen production and solid oxide fuel cells (SOFCs). Cobalt (Co) is an important catalyst for dry and steam methane reforming. However, previous studies have confirmed that metal Co surfaces only have weak adsorption activity for H2O, which is evidently unfavorable for steam reforming. In this work we used first-principles simulations to study the activity of MnO–Co catalysts for the adsorption of H2O,...

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

**PageRank centrality for temporal networks**

Publication date: Available online 23 January 2019Source: Physics Letters AAuthor(s): Laishui Lv, Kun Zhang, Ting Zhang, Dalal Bardou, Jiahui Zhang, Ying CaiAbstractIn this paper, we propose a new centrality measure for ranking the nodes and time layers of temporal networks simultaneously, referred to as the f-PageRank centrality. The f-PageRank values of nodes and time layers in temporal networks are obtained by solving the eigenvector of a multi-homogeneous map. The existence and uniqueness of the proposed centrality measure are also guaranteed by existing results, under some reasonable conditions. The numerical experime...

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

**MMSE detection method in uplink massive MIMO systems based on quantum computing**

Publication date: Available online 23 January 2019Source: Physics Letters AAuthor(s): XiaoJun Wang, Jie Zhao, FanXu Meng, XuTao Yu, ZaiChen ZhangAbstractThe minimum mean square error (MMSE) detection method involved matrix inversion operation with excessive computational burden. In this paper, we develop an improved quantum linear system algorithm to solve matrix inversion problem of the MMSE detection method in uplink massive multiple-input and multiple-output (MIMO) systems. In order to apply reasonably the robust computational power of quantum computing, we optimize the preparation of the input state and the extraction ...

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

**Editors**

Publication date: 4 February 2019Source: Physics Letters A, Volume 383, Issue 7Author(s): (Source: Physics Letters A)

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

**Quantum information capsule and information delocalization by entanglement in multiple-qubit systems**

Publication date: Available online 21 January 2019Source: Physics Letters AAuthor(s): Koji Yamaguchi, Naoki Watamura, Masahiro HottaAbstractWhere do entangled multiple-qubit systems store information? For information injected into a qubit, this question is nontrivial and interesting since the entanglement delocalizes the information. So far, a common picture is that of a qubit and its purification partner sharing the information quantum mechanically. Here, we introduce a new picture of a single qubit in the correlation space, referred to as quantum information capsule (QIC), confining the information perfectly. This pictur...

**Source: **Physics Letters A - January 22, 2019 **Category: **Physics **Source Type: **research

**The intrinsical character of the electronic correlation in an electron gas**

Publication date: Available online 21 January 2019Source: Physics Letters AAuthor(s): Yu-Liang LiuAbstractBy introducing the phase transformation of electron operators, we map the equation of motion of an one-particle Green's function into that of a non-interacting one-particle Green's function where the electrons are moving in a time-depending scalar potential and pure gauge fields for a D-dimensional electron gas, and we demonstrate that the electronic correlation strength strongly depends upon the excitation energy spectrum and collective excitation modes of electrons. It naturally explains that the electronic correlati...

**Source: **Physics Letters A - January 22, 2019 **Category: **Physics **Source Type: **research

**Inherent spectral distortions in pump-probe Brillouin scattering spectroscopy**

Publication date: Available online 21 January 2019Source: Physics Letters AAuthor(s): V.I. KovalevAbstractIt is shown that the pump-probe technique in Brillouin scattering spectroscopy is accompanied by two specific distortions to a registered spectrum. The first appears due to an acoustic wave that unavoidably accompanies in a continuous medium the density wave driven by the pump and probe signals. The registered spectrum then splits to two spectral components, one corresponding to the propagation velocity of the driven density wave, and the other to the acoustic velocity. The other distortion is asymmetry of the spectrum...

**Source: **Physics Letters A - January 22, 2019 **Category: **Physics **Source Type: **research

**Spin switch effect in multiply connected superconductor-ferromagnet hybrid geometry**

Publication date: Available online 21 January 2019Source: Physics Letters AAuthor(s): B. KrunavakarnAbstractWe consider a superconducting spin valve in multiply connected superconductor-ferromagnet hybrid geometry such as a superconducting ring enclosed a ferromagnetic metal, in the framework of linearized Usadel equations. We simplify our model by considering the presence of the exchange field in the superconducting ring which allows us to manipulate magnetization orientations in parallel or antiparallel configurations by switching the weaker exchange field. In such geometry the superconducting ground state is activated t...

**Source: **Physics Letters A - January 22, 2019 **Category: **Physics **Source Type: **research

**Scanning tunneling microscopy studies in the heavy fermion system with even and odd hybridization**

Publication date: Available online 21 January 2019Source: Physics Letters AAuthor(s): Fu-Bin YangAbstractThe effect of even and odd hybridization for scanning-tunneling microscopy process in the heavy fermion system is studied by the nonequilibrium Green function method. It is found that an even hybridization leads to symmetric density of states (DOS), while an odd hybridization leads to the vanishing of the DOS of the nondiagonal term. Besides, the differential conductance under the even hybridization is the natural consequence of the existence of van Hove singularities. In the odd hybridization situation, the differentia...

**Source: **Physics Letters A - January 22, 2019 **Category: **Physics **Source Type: **research

**Effect of energy dependent cross-section on flow velocity measurements with charge exchange spectroscopy in magnetized plasma**

Publication date: Available online 21 January 2019Source: Physics Letters AAuthor(s): J. Chen, K. Ida, M. Yoshinuma, I. Murakami, T. Kobayashi, M.Y. Ye, B. LyuAbstractCharge exchange spectroscopy (CXS) is widely used to measure plasma flow velocity. Accurate measurement is heavily affected by energy dependent cross section between neutral atoms and impurity ions. One symmetric layout of poloidal CXS is applied on Large Helical Device. Correction velocity due to the cross section is exacted from total velocity when actual plasma flow velocity is acquired with the benefit of this layout. A linear relationship between correct...

**Source: **Physics Letters A - January 22, 2019 **Category: **Physics **Source Type: **research

**Rashba control to minimize circuit cost of quantum Fourier algorithm in ballistic nanowires**

Publication date: Available online 21 January 2019Source: Physics Letters AAuthor(s): A.H. Homid, M.R. Sakr, A.-B.A. Mohamed, M. Abdel-Aty, A.-S.F. ObadaAbstractThe presented work provides a new prospective of quantum computer hardware development through ballistic nanowires with Rashba effect. We address Rashba effect as a possible mechanism to realize novel qubit gates in nanowires. We apply our results to the design of a new quantum circuit for Fourier algorithm, which shows an improved quantum cost in terms of the number of gates. The current system can be successfully implemented to increase the production of quantum ...

**Source: **Physics Letters A - January 22, 2019 **Category: **Physics **Source Type: **research

**Axial momentum for the relativistic Majorana particle**

Publication date: Available online 21 January 2019Source: Physics Letters AAuthor(s): H. ArodźAbstractThe Hilbert space of states of the relativistic Majorana particle consists of normalizable bispinors with real components, hence the usual momentum operator −i∇ can not be defined in this space. For this reason, we introduce the axial momentum operator, −iγ5∇ as a new observable for this particle. In the Heisenberg picture, the axial momentum contains a component which oscillates with the amplitude proportional to m/E, where E is the energy and m the mass of the particle. The presence of the ...

**Source: **Physics Letters A - January 22, 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 [J. Phys. A: Math. Gen. 26, 1211 (1993)]. 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 agree ...

**Source: **Physics Letters A - January 22, 2019 **Category: **Physics **Source Type: **research

**Formation of intermediate coupling optical polarons and bipolarons in two-dimensional systems**

Publication date: Available online 22 January 2019Source: Physics Letters AAuthor(s): S. Dzhumanov, P.J. Baimatov, Sh.T. Inoyatov, Sh.S. Djumanov, A.G. GulyamovAbstractThe formation of the optical polaron and bipolaron in two-dimensional (2D) systems is studied in the intermediate electron–phonon coupling regime. The total energies of the 2D polaron and bipolaron are calculated by using the Buimistrov–Pekar method of canonical transformations. The obtained results are compared with other existing results obtained by using the Feynman path integral method and the modified Lee–Low–Pines unitary transf...

**Source: **Physics Letters A - January 22, 2019 **Category: **Physics **Source Type: **research

**Edge intensity-based community measurement in complex networks**

Publication date: Available online 18 January 2019Source: Physics Letters AAuthor(s): Hao LongAbstractCommunity is the dominant structure of complex networks. In recent years, community detection has become a heavily researched issue in network science, and many algorithms have been proposed to solve it. However, how to evaluate these algorithms and measure the strength of community structures is still an open problem. The modularity, as well as many of its variants, is widely used for this purpose, and maximizing such metrics is also a main approach to uncover communities, but this technique has a resolution limit problem...

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

**Cooperation in the spatial public goods game with the second-order reputation evaluation**

Publication date: Available online 18 January 2019Source: Physics Letters AAuthor(s): Yuetian Dong, Gang Hao, Juan Wang, Chen Liu, Chengyi XiaAbstractThe existence of reputation can significantly promote the level of cooperation within the human population. In the recent years, most of the researches were based on binary image score or first-order evaluation standard. In this paper, we propose a second-order reputation evaluation model, in which the individual's image score will change not only in accordance with his own strategy, but also the reputation value of neighbors. Individuals try to enhance their reputation to co...

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

**Double Hopf bifurcation induces coexistence of periodic oscillations in a diffusive Ginzburg–Landau model**

Publication date: Available online 16 January 2019Source: Physics Letters AAuthor(s): Yanfei Du, Ben Niu, Yuxiao Guo, Jianquan LiAbstractWe perform bifurcation analysis in a complex Ginzburg–Landau system with delayed feedback under the homogeneous Neumann boundary condition. We calculate the amplitude death region, and it turns out that the boundary of the amplitude death region consists of two Hopf bifurcation curves with wave number zero. The existence conditions for double Hopf bifurcations are established. Taking the feedback strength and time delay as bifurcation parameters, normal forms truncated to the third ...

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

**SERS-signal optimised AgNPs-plated-ZnO nanoflower-like structure synthesised for sensing applications**

Publication date: Available online 17 January 2019Source: Physics Letters AAuthor(s): Tianhui Jiao, Felix Y.H. Kutsanedzie, Jing Xu, Annavaram Viswadevarayalu, Md Mehedi Hassan, Huanhuan Li, Yi Xu, Quansheng ChenAbstractAgNPs-plated-ZnO nanoflower (NFs)-like structures (Ag@ZnO NFs) with optimised signals were synthesised via wet chemical method at different temperatures (50 - 80 °C). The enhancement factors (EFs) computed for the resultant Ag@ZnO ranged between 2.36 - 8.46×107 obtained at the different temperatures using 4-aminothiophenol (4-ATP). The achieved EF results indicate Ag@ZnO synthesised at 50 °C g...

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

**Transient thin film flow of nonlinear radiative Maxwell nanofluid over a rotating disk**

Publication date: Available online 17 January 2019Source: Physics Letters AAuthor(s): Jawad Ahmed, Masood Khan, Latif AhmadAbstractIn this letter, a mathematical model for transient nature thin film flow of Maxwell nanofluid over a rotating disk is studied in the presence of a uniform magnetic field and non-linear thermal radiation. The Brownian motion and thermophoresis features due to nanofluid are captured by adopting the Buongiorno model. The prime emphasize is to explore the temperature field and nanoparticles volume fraction in nanofluid thin film flow. The reduced system of differential equations is solved numerical...

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

**Thermal properties of triangle nitrogen-doped graphene nanoribbons**

Publication date: Available online 17 January 2019Source: Physics Letters AAuthor(s): Bing Yang, Dongbo Li, Liang Qi, Tianbo Li, Ping YangAbstractWe investigate the thermal properties of triangle nitrogen-doped graphene nanoribbons (TNGNs) with different nitrogen-doped concentrations (0.11% to 2.31%) at different temperatures (200K∼600K) using non-equilibrium molecular dynamics. The results show that the nitrogen atoms doped at the edge of the defect can increase the thermal conductivity of graphene nanoribbons, but with the increase of the nitrogen-doped concentrations from 0.11% to 2.31%, the thermal conductivity dec...

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

**Study of the q-Gaussian distribution with the scale index and calculating entropy by normalized inner scalogram**

Publication date: Available online 17 January 2019Source: Physics Letters AAuthor(s): Mahmut Akıllı, Nazmi Yılmaz, K. Gediz AkdenizAbstractIn this paper, we discuss a method based on wavelet analysis for the study of the q-index of the Gaussian distribution. We derive q-index from the scale index, iscale, using the expression; q≡1+2iscale where iscale is a wavelet based tool for measuring the degree of aperiodicity of a dynamical system in the range of 0≤iscale≤1. We show that this expression gives consistent results with the numerical approach of q-Gaussian distribution which determines the degree of non-ex...

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

**The Role of CdCl2 Treatments and Annealing in the Formation of Sintered CdTe Nanocrystal Solar Cells**

Publication date: Available online 17 January 2019Source: Physics Letters AAuthor(s): G. Jain, A. Ahnood, A. Chanaewa, K. Fox, P. MulvaneyAbstractSolution processing of CdTe nanocrystals is a promising approach for the fabrication of low cost photovoltaic devices at low process temperatures. However despite the inherent advantages of this approach, the nanoscale physical mechanisms underlying the fabrication process are not well understood. Here we demonstrate that chemical treatment of CdTe nanoparticles leads to the production of a deep valence band edge. However, the removal of ligands also introduces sizable quantities...

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

**Heat and mass transfer analysis of time-dependent tangent hyperbolic nanofluid flow past a wedge**

Publication date: Available online 16 January 2019Source: Physics Letters AAuthor(s): S.M. Atif, S. Hussain, M. SagheeAbstractThe candid intension of this article is to inspect the heat and mass transfer of a magnetohydrodynamic tangent hyperbolic nanofluid. The nanofluid flow has been assumed to be directed by a wedge on its way. In addition, the collective stimulus of the convective heating mode with thermal radiation is inspected. The governing set of PDEs is rendered into that of the coupled nonlinear ODEs. The resulting ordinary differential equations are then solved by the well known shooting technique for two differ...

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

**Stay-eat or run-away: Two alternative escape behaviors**

Publication date: Available online 16 January 2019Source: Physics Letters AAuthor(s): Shuai Zhang, Mingyong Liu, Xiaokang Lei, Yunke HuangAbstractPursuit-and-evasion behavior in groups of animals is a phenomenon that can be easily observed in nature. Immediate flight upon detection is a common but not exclusive response for prey with both stay-eat behavior and run-away behavior occur during the predation process. It remains unclear why these two contrasting survival tactics appear, what the triggering conditions are and what internal mechanisms are at play. Here we investigate the effect of energy level on the behavior of ...

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

**Magnetic anisotropy of ferromagnetic metals in low-symmetry systems**

Publication date: Available online 16 January 2019Source: Physics Letters AAuthor(s): Yoshishige Suzuki, Shinji MiwaAbstractWe have constructed an analytic formula to treat the perpendicular magnetic anisotropy energy in ferromagnetic metals with low symmetry, such as C4V and C3V. We find that the anisotropy energy is proportional to a part of the expectation values of the orbital angular momentum and magnetic dipole operator. Although the result is similar to the model proposed by Laan (1998) [2], we have derived a concrete expression for the spin-flip virtual excitation process term, which can be dominant in atoms with s...

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

**Green's function approach to the impurity state in the Lieb lattice**

Publication date: Available online 16 January 2019Source: Physics Letters AAuthor(s): Rui ZhuAbstractWavefunction of an impurity attached to the Lieb lattice is considered by directly computing the Green's function (GF) for the nearest-neighbor tight-binding model. By replacing the lattice GF with a GF array including all the nine GFs defining on the three-atom unit cell of the Lieb lattice, an accurate and efficient numerical technique is developed. Agreement of both the real and imaginary components of the GF between numerical simulation of the lattice GF and continuum-space Fourier transformation is achieved in the whol...

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

**A special type of explosion of basin boundary**

Publication date: Available online 16 January 2019Source: Physics Letters AAuthor(s): Guiqin Kong, Yongxiang ZhangAbstractWe study a special type of explosion of a basin boundary set in an archetypal oscillator. A typical feature is that the basin boundaries change the number of basins separating at the same time. Before the explosion, a basin boundary contains some Wada points of ten basins. After the explosion, the basin boundary contains some Wada points of eighteen basins. The underlying mechanism for the explosion is investigated by the heteroclinic tangency and Lambda lemma. Basin entropy and boundary basin entropy a...

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