Effects of dipole-dipole interaction on entanglement transfer

A system consisting of two different atoms interacting with a two-mode vacuum, where each atom is resonant only with one cavity mode, is considered. The effects of dipole-dipole （dd） interaction between two atoms on the atom-atom entanglement and mode--mode entanglement are investigated. For a weak dd interaction, when the atoms are initially separable, the entanglement between them can be induced by the dd interaction, and the entanglement transfer between the atoms and the modes occurs efficiently; when the atoms are initially entangled, the entanglement transfer is almost not influenced by the dd interaction. However, for a strong dd interaction, it is difficult to transfer the entanglement from the atoms to the modes, but the atom-atom entanglement can be maintained when the atoms are initially entangled.     

Generation of multipartite entangled states by cavity QED

We propose the methods of generating multipartite entanglement by considering the interaction of a system of N two-level atoms in M cavities of high quality factor with a strong classical driving field. It is shown that, with the cavity detuning, the applied driving field detuning and vacuum Rabi coupling, we can produce an entangled coherent state in two single-mode cavities and generate the entangled coherent cluster states in two bimodal vacuum cavities. Tuning these parameters also allows us to acquire the anti-Jaynes-Cummings （AJC） interaction, with which we can generate the maximally two-photon entangled states, and the two-atom and the two-photon entangled cluster states.     

Effect of thermal-annealing on the magnetoresistance of manganite-based junctions

Thermal-annealing has been widely used in modulating the oxygen content of manganites. In this work, we have studied the effect of annealing on the transport properties and magnetoresistance of junctions composed of a La0.9Ca0.1MnO3＋6 film and a Nb-doped SrTiO3 substrate. We have demonstrated that the magnetoresistance of junctions is strongly dependent on the annealing conditions： Prom the junction annealed-in-air to the junction annealedin-vacuum, the magnetoresistance near 0-V bias can vary from ～-60% to N～0. A possible mechanism accounting for this phenomenon is discussed.     

The relativistic bound states for a new ring-shaped harmonic oscillator

In this paper a new ring-shaped harmonic oscillator for spin 1/2 particles is studied, and the corresponding eigenfunctions and eigenenergies are obtained by solving the Dirac equation with equal mixture of vector and scalar potentials. Several particular cases such as the ring-shaped non-spherical harmonic oscillator, the ring-shaped harmonic oscillator, non-spherical harmonic oscillator, and spherical harmonic oscillator are also discussed.     

Kac-Moody-Virasoro symmetry algebra of a （2＋1）-dimensional bilinear system

Based on some known facts of integrable models, this paper proposes a new （2＋1）-dimensional bilinear model equation. By virtue of the formal series symmetry approach, the new model is proved to be integrable because of the existence of the higher order symmetries. The Lie point symmetries of the model constitute an infinite dimensional Kac- Moody Virasoro symmetry algebra. Making use of the infinite Lie point symmetries, the possible symmetry reductions of the model are also studied     

Modelling of spreading process: effect from hydrogen bonds

Lubricant spreading on solid substrates has drawn considerable attention not only for the microscopic wetting theory but also for the dramatic application in head-disk interface of magnetic storage drive systems. Molecular dynamic simulation based on a coarse-grained bead-spring model has been used to study such a spreading process. The spreading profiles indicate that the hydrogen bonds among lubricant molecules and the hydrogen bonds between lubricant molecules and polar atoms of solid substrates will complicate the spreading process in a tremendous degree. The hydrogen bonds among lubricant molecules will strengthen the lubricant combination intensity, which may hinder most molecules from flowing down to the substrates and diffusing along the substrates. And the hydrogen bonds between lubricant molecules and polar atoms of solid substrates will confine the lubricant molecules around polar atoms, which may hinder the molecules from diffusing along the substrates and cause precursor film to vanish.     

Dynamical study on charge injection and transport in a metal/polythiophene/metal structure

The dynamical process of charge injection from metal electrode to a nondegenerate polymer in a metal/polythiophene （PT）/metal structure has been investigated by using a nonadiabatic dynamic approach. It is found that the injected charges form wave packets due to the strong electron-lattice interaction in PT. We demonstrate that the dynamical formation of the wave packet sensitively depends on the strength of applied voltage, the electric field, and the contact between PT and electrode. At a strength of the electric field more than 3.0 × 10^4 V/cm, the carriers can be ejected from the PT into the right electrode. At an electric field more than 3.0 × 10^5 V/cm, the wave packet cannot form while it moves rapidly to the right PT/metal interface. It is shown that the ejected quantity of charge is noninteger.     

Bound entangled states invariant under Ux

This paper obtains an entangled condition for isotropic-like states by using an atomic map. It constructs a class of bound entangled states from the entangled condition and shows that the partial transposition of the state from the constructed bound entangled class is an edge bound entangled state by using range criterion.     

量子Generalized Reed-Solomon码

构造出了一族量子纠错码，这族码具有参数［［n，n-2k，k+1］］_q，是q维量子系统上的码，q是任意素数的幂.这族码的最小距离达到了理论上限，因此，以码距来说，它是最优的.证明了当2≤n≤q或者q²-q+2≤n≤q²时，码都是存在的.     

飞秒脉冲振幅和相位的无干涉条纹重构法测量

对作者所提出的无干涉条纹直接电场重构测量飞秒脉冲的振幅和相位的新方法作出进一步理论分析，并通过实验测量说明该方法的优越性.该方法克服了传统的SPIDER方法的弊病，能得到一组无干涉条纹的图像，排除传统方法必须使用傅里叶变换滤波消除干涉条纹而引进的系统误差，使得该方法能够采用较简便设备且能较准确测量飞秒脉冲强度轮廓和相位.最后给出同一条件下新方法和传统SPIDER方法分别重构的脉冲强度自相关曲线与实验测量结果的比较，以说明新方法的有效性和优越性.