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Abstract: The tripartite nonlocality is measured by the extent of violation of multipartite Bell inequality in Tavis-Cummings model with cavity loss. The effect of Bell-nonlocality sudden death is demonstrated. It is important that the study of tripartite system can exhibit fundamental characteristics which do not exist in bipartite systems. [Copyright &y& Elsevier]

Abstract: Landauer''s principle is fundamental for the physics of information. It establishes the least amount of energy that needs to be dissipated in order to erase a bit of information. Using the Beck–Cohen representation of statistical ensemble distributions, we explore an extension of Landauer''s principle to systems out of equilibrium. [Copyright &y& Elsevier]

Abstract: By analyzing an instructive example, for testing many concepts and approaches in quantum mechanics, of a one-dimensional quantum problem with moving infinite square-well, we define geometric phase of the physical system. We find that there exist three dynamical phases from the energy, the momentum and local change in spatial boundary condition respectively, which is different from the conventional computation of geometric phase. The results show that the geometric phase can fully describe the nonlocal character of quantum behavior. [Copyright &y& Elsevier]

Abstract: By means of the modified extended tanh-function (METF) method the multiple traveling wave solutions of some different kinds of nonlinear partial differential equations are presented and implemented in a computer algebraic system. The solutions for the nonlinear equations such as variants of the RLW and variant of the PHI-four equations are exactly obtained and so the efficiency of the method can be demonstrated. [Copyright &y& Elsevier]

Abstract: Recently suggested microscopic theory of collective dynamics of a liquid has been used to successfully explain the detailed experimental dynamic structure factor of liquid mercury at room temperature, observed experimentally recently using high resolution inelastic X-ray scattering for various momentum transfers lying in the range 3 nm−1–37.1 nm−1. [Copyright &y& Elsevier]

Abstract: We report on the observation of highly anisotropic viscous electronic conducting phase in amorphous WO1.55 films that occurs below a current (I)- and frequency (f)-dependent temperature . At the rotational symmetry of randomly disordered electronic background is broken leading to the appearance of mutually perpendicular metallic- and insulating-like states. A rich dynamic behavior of the electronic matter occurring at provides evidence for an interplay between pinning effects and electron–electron interactions. The results suggest a dynamic crystallization of the disordered electronic matter, viz. formation of sliding Wigner crystal, as well as the occurrence of quantum liquid-like crystal or stripe phase at low drives. [Copyright &y& Elsevier]

Abstract: We present a generalization of the pioneering results obtained for single K-shell photoionization of H-like ions by M. Stobbe [M. Stobbe, Ann. Phys. 7 (1930) 661] to the case of the helium isoelectronic sequence. The total cross section of the process is calculated, taking into account the correlation corrections to first order of the perturbation theory with respect to the electron–electron interaction. Predictions are made for the entire non-relativistic energy domain. The phenomenon of dynamical suppression of correlation effects in the ionization cross section is discussed. [Copyright &y& Elsevier]

Abstract: The structural transition in inner portions of medium-sized silicon clusters has been a puzzle over a decade. By performing extensive search of the “compressing-liquid-silicon” strategy we proposed together with the “stuffing-fullerene” approach, the low-lying structures of () are achieved. We reveal that the surfaces of these low-lying isomers are endohedral silicon fullerenelike cages, and the inner portions evolve from loose patterns to aggregate structures as the cluster size increases. These findings not only imply that the stuffed-cage structures are the preferred growth pattern for still, but also clue that before becoming a bulk pattern, the inner portions of clusters undergo transition states. [Copyright &y& Elsevier]

Abstract: Temperature-dependent high-resolution optical spectra of the Er3+ probe ion in DyFe3(BO3)4 and HoFe3(BO3)4 are reported. The data provide the temperature of magnetic ordering and direction of the Fe3+ magnetic moments. Both compounds order magnetically at . The magnetic structure of DyFe3(BO3)4 is of the easy-axis type, while that of HoFe3(BO3)4 is of the easy-plane type. The role of anisotropic interactions between the iron and the rare-earth subsystems is discussed. [Copyright &y& Elsevier]

Abstract: We present a relativistic single particle simulation of vacuum acceleration of an electron by a high-intensity radially polarized laser beam. The inherent complete symmetry of radially polarized laser beam leads to improvement in the trapping and acceleration of an electron so that an electron can be accelerated to the level of GeV. In addition, the external magnetic field further enhances the electron acceleration. Hence, an electron of ultrahigh energy was observed. The strong correlation between final electron energy and scattering angle is discussed. [Copyright &y& Elsevier]

Abstract: We investigate the collective excitations of a one-dimension Bose–Einstein condensate trapped in an anharmonic potential by solving the time-dependent Tonks–Girardeau equation. The governing equations of motions for the low-energy excitations are obtained using variational approaches. The motion of a 1D BEC in a harmonic trap is just like the motion of one particle in a harmonic trap. And quartic distortion of the potential causes the blue-shift and red-shift on the excitation frequency while cube distortion only causes the red-shift. [Copyright &y& Elsevier]

Abstract: The method of self-similar factor approximants is completed by defining the approximants of odd orders, constructed from the power series with the largest term of an odd power. It is shown that the method provides good approximations for transcendental functions. In some cases, just a few terms in a power series make it possible to reconstruct a transcendental function exactly. Numerical convergence of the factor approximants is checked for several examples. A special attention is paid to the possibility of extrapolating the behavior of functions, with arguments tending to infinity, from the related asymptotic series at small arguments. Applications of the method are thoroughly illustrated by the examples of several functions, nonlinear differential equations, and anharmonic models. [Copyright &y& Elsevier]

Abstract: This Letter presents an adaptive neural network control method for the chaos control problem. Based on a single layer neural network, the dynamic about the unstable fixed period point of the chaotic system can be adaptively identified without detailed information about the chaotic system. And the controlled chaotic system can be stabilized on the unstable fixed period orbit. Simulation results of Henon map and Lorenz system verify the effectiveness of the proposed control method. [Copyright &y& Elsevier]

Abstract: The harmonic balance (HB) method as an analytical approach is widely used for nonlinear oscillators, in which the initial conditions are generally simplified by setting velocity or displacement to be zero. Based on HB, we establish a new theory to address nonlinear conservative systems with arbitrary initial conditions, and deduce a set of over-determined algebraic equations. Since these deduced algebraic equations are not solved directly, a minimization problem is constructed instead and an iterative algorithm is employed to seek the minimization point. Taking Duffing and Duffing-harmonic equations as numerical examples, we find that these attained solutions are not only with high degree of accuracy, but also uniformly valid in the whole solution domain. [Copyright &y& Elsevier]

Abstract: The decoherence process of a central spin-1/2 particle coupling to the surrounding anisotropy spin-1/2 chain in a transverse field at finite temperature is studied in this Letter. We study the Loschmidt echo(LE) of the central spin when the surrounding spin chain is in the thermal equilibrium state. Our results show that the critical enhanced decay of LE at zero temperature becomes indistinct with the temperature increasing and will be completely washed out when the temperature is high enough. [Copyright &y& Elsevier]

Abstract: The semiclassical limit for Dirac particles interacting with a static gravitational field is investigated. A Foldy–Wouthuysen transformation which diagonalizes at the semiclassical order the Dirac equation for an arbitrary static spacetime metric is realized. In this representation the Hamiltonian provides for a coupling between spin and gravity through the torsion of the gravitational field. In the specific case of a symmetric gravitational field we retrieve the Hamiltonian previously found by other authors. But our formalism provides for another effect, namely, the spin hall effect, which was not predicted before in this context. [Copyright &y& Elsevier]

Abstract: We study the flip-processes in a two-level system, which is triggered by the coupling to a classical bath. When the bath is represented by a stochastic field, the time evolution of the density matrix leads to a stochastic equation with a multiplicative noise. Accordingly the Fokker–Planck-equation (FPE) depends on the matrix elements of the underlying density operator. The solution of the FPE can be parametrized in terms of an inherent conserved quantity α, which is interpreted as a measure for the persistence of quantum information. We show that the FPE exhibits a single unique steady state solution different from Boltzmann''s law. The exactly computable discrete spectrum of the relaxation times is characterized by two quantum numbers and the ratio of Planck''s constant and the coupling strength to the bath. The total entropy is analyzed as function of the quantum number α. In case of the system is in a pure state whereas for a mixed state is realized. In case of two, two-level systems, immersed in the common bath, the two noninteracting two-level systems become mutually entangled. The annealed entropy is in that case non-extensive. [Copyright &y& Elsevier]

Abstract: We solve the longstanding problem of the distribution between the neighboring energy levels in generic (partially chaotic) quantum systems. The distribution we obtain is in excellent agreement with the data obtained from atomic physics, optics and acoustics. [Copyright &y& Elsevier]

Abstract: We propose a scheme to generate a W state of qubits trapped in two spatially separated cavities respectively by means of entanglement transfer. We find that the 2n qubits will be entangled in the W state periodically. The influence of cavity dissipation is also analytically demonstrated. [Copyright &y& Elsevier]

Abstract: We derive the explicit transformation of the optimal symmetric economical phase-covariant quantum cloning machine (EPCCM), which works without ancilla, as well as the corresponding fidelities in 2-dimension. The fidelity () is covered with previous contributions [G.M. D''Ariano, et al., Phys. Rev. A 71 (2005) 042327]. Meanwhile, the explicit transformation of the optimal symmetric phase-covariant quantum cloning machine (PCCM) (working with ancilla) as well as the corresponding fidelities in 2-dimension is also derived. The results of the PCCM agree with previous contributions [H. Fan, et al., Phys. Rev. A 65 (2001) 012304]. [Copyright &y& Elsevier]

Abstract: We propose simple experimental scheme for direct measurement of the exponential phase moments of single-mode cavity field. The scheme is based on the adiabatic passage technique, and all the relevant quantities can be obtained directly from the measurement of atomic populations. We also point out that scheme can be used to measure Q-function of single-mode cavity fields and verify the phase-number uncertainty relation. [Copyright &y& Elsevier]

Abstract: A protocol for multiparty quantum secret splitting (MQSS) with an ordered N Einstein–Podolsky–Rosen (EPR) pairs and Bell state measurements is recently proposed by Deng et al. [F.G. Deng et al., Phys. Lett. A 354 (2006) 190]. We analyzed the security of the protocol and found that this protocol is secure for any other eavesdropper except for the agent Bob who adopts intercept-and-resend attack. Bob can obtain all the information of Alice''s alone without being found. We also propose an improved version of the MQSS protocol. [Copyright &y& Elsevier]

Abstract: A new generalized moments expansion (GMX), which is based on the t-expansion, is derived. The well-known connected moments expansion (CMX) and alternate moments expansion (AMX) are shown to be special cases of the GMX. [Copyright &y& Elsevier]

Abstract: This Letter discusses the equivalence between the Bowen measure associated with the set of periodic points of period n of hyperbolic area-preserving maps of a smooth manifold, and the measure associated with the intersections between stable and unstable manifolds of hyperbolic points. In typical cases of physical interest (i.e., nonuniformly hyperbolic systems) these measures are found to be highly nonuniform (multifractal). [Copyright &y& Elsevier]

Abstract: We investigate the quantum version of the Stackelberg duopoly with incomplete information, especially how the quantum entanglement affects the first-mover advantage in the classical form. It is found that while positive entanglement enhances the first-mover advantage beyond the classical limit, the advantage is dramatically suppressed by negative entanglement. Moreover, despite that positive quantum entanglement improves the first-mover''s tolerance for the informational incompleteness, the quantum effect does not change the basic fact that Firm A''s lack of complete information of Firm B''s unit cost is eradicating the first-mover advantage. [Copyright &y& Elsevier]

Abstract: We propose a scheme by which two parties can secretly and simultaneously exchange messages. The scheme requires the two parties to share entanglement and both to perform Bell-state measurements. Only two out of the four Bell states are required to be distinguished in the Bell-state measurements, and thus the scheme is experimentally feasible using only linear optical means. Generalizations of the scheme to high-dimensional systems and to multipartite entanglement are considered. We show also that the proposed scheme works even if the two parties do not possess shared reference frames. [Copyright &y& Elsevier]

Abstract: We suggest a procedure of generating entanglement between particles at distant positions such that they cannot be directly entangled via local interaction. An already entangled pair is used to transfer the entanglement to another pair of particles by way of interaction. This scheme of nonlocal generation of entanglement can be used in the construction of a two-qubit universal gate. [Copyright &y& Elsevier]

Abstract: We discuss the results of a numerical study on the stability of two-dimensional vorticity filaments around a circular vortex. We illustrate how the stability of the filaments depends on the balance between the strain associated with the far field of the vortex and the local vorticity of the filament, and we discuss an empirical criterion for filament stability. [Copyright &y& Elsevier]

Abstract: Recently, Clarisse [L. Clarisse, Phys. Lett. A 359 (2006) 603] and Ha [K.-C. Ha, Phys. Lett. A 361 (2007) 515] found examples of types and entangled states with positive partial transposes. In this Letter, we show that their examples have the Schmidt number as 2. [Copyright &y& Elsevier]

Abstract: We demonstrate that radiative transitions with are strongly dominating for all values of n and l, except small region where . [Copyright &y& Elsevier]

Abstract: We present exact formulas solving the problem of partitioning the total number of period-k orbits of the area-preserving Hénon map into the number of orbits building its three possible conjugacy classes. The formulas are valid for any arbitrary period k. They are derived with combinatorial methods and constitute a nice application of the number-theoretic Möbius inversion formula to a key problem in physics and dynamical systems. A handy MAPLE implementation of the formulas is also provided. [Copyright &y& Elsevier]

Abstract: We present a quantum key distribution scheme, based on polarization encoding, that is robust against collective noise by sending orthogonal polarization modes of each photon through different channels and postselection. It has lower bit error rate and only needs local polarization measurement. Compare with similar schemes is discussed. [Copyright &y& Elsevier]

This Letter shows that a single multipartite entangled mixed state in a multipartite system with dimension 2⊗2⊗⋯⊗2 cannot be purified to an entangled pure state under local manipulation. In general, a generic multipartite entangled mixed state cannot be purified. For a class of entangled mixed states, the fidelity can never be increased. [Copyright &y& Elsevier]

Abstract: In the Letter [B.A. Nguyen, Phys. Lett. A 350 (2006) 174], a quantum exam protocol was presented. Here we show a cheating protocol, by which any student can get the other students'' solution without being detected. Then we propose a possible modified protocol against this attacking strategy. [Copyright &y& Elsevier]