Modern Physics Letters B

The generalized two-dimensional Peierls–Nabarro (PN) model⁷ for studying interfaces is developed further, where an exact generalized stacking fault energy γ-surface obtained from ab initio calculations acts as an input function for the generalized PN model. Using the multiscale modeling techniques, which combines elastic theory with ab initio calculations, the structure and energy of the Al/MgO(100) interface are studied, and the effectiveness of this method is demonstrated.

We propose a method to generate multiphoton polarization-entangled cluster states of any number photons by using the fusion operations of two-photon cluster states and a kind of local operation, and then analyze the process of open-destination teleportation of a single photon state using the generated states. Apart from theoretical deductions, we also give the experimentally schematic diagram, which requires only BBOs, Polarization Beam Splitters, half-wave plates, single photon resources as well as some other linear optical elements. The equipment and techniques used here are all feasible under current technology.

By the Wertheim method, the exact solution of the Percus–Yevick integral equation for a system of particles with the "repulsive step potential" interacting ("collapsing" hard spheres) is obtained. On the basis of this solution, the state equation for the "repulsive step potential" is built and determined, that the Percus–Yevick equation does not show the Van der Waals loop for "collapsing" hard spheres.

In this paper, the problem of global asymptotic stability of stochastic neural networks of neutral type is considered. Based on the Lyapunov stability theory, a new delay-dependent stability criterion for the network is derived in terms of LMI (linear matrix inequality). A numerical example is given to show the effectiveness of the proposed method.

We find that when a single Josephson junction is inserted into a mesoscopic LC circuit, the operator Josephson equation is modified accompanying with the modification of Farady equation describing the inductance. By virtue of the entangled state representation and using the appropriate phase operator in bosonic form we derive the modified equations.

Based on a 2 × 2 eigenvalue problem, a new (2+1)-dimensional soliton equation is proposed. Moreover, we obtain a finite-dimensional Hamiltonian system. Then we verify it is completely integrable in the Liouville sense. In the end, we introduce a set of H_k polynomial integrable, by which we can separate the solition equation into three compantiable Hamiltonian systems of ordinary differential equation.

Powder X-ray diffraction, Raman scattering and infrared spectra at different doping (x = 0 ~ 0.5) on polycrystalline Pr_1-xSr_1+xCoO₄ were performed. With increasing x, the shift of Raman scattering spectra is due to the enhancement of electron–phonon interaction along the c-axis. The contrary variation of infrared in wavenumber comes from the weakening electron–phonon interactions in the ab plane. There is a dramatic variation in resistivity as x increases, which is also caused by increasing carrier concentration and is related to the band shift. For Pr_1-xSr_1+xCoO₄, both A_1g bands shift to low frequency and reach a minimum when x = 0.3 and the resistivity of Pr_0.7Sr_1.3CoO₄ is the smallest at room temperature.

The third-order optical nonlinear properties of CdSe quantum dots (QDs) and CdSe-C₆₀ QDs are investigated by Z-scan technique with picosecond pulses at the wavelength of 800 nm. The value of the nonlinear absorption coefficient β of CdSe-C₆₀ QDs is measured to be 2.9 cm/GW, which is about two times larger than that of CdSe QDs. The nonlinear refraction index γ of CdSe-C₆₀ QDs is -2.8 × 10^-3cm²/GW, which is about seven times larger than that of CdSe QDs. Presence of C₆₀ contributes to the larger optical nonlinearity of CdSe-C₆₀ QDs comparing with CdSe QDs.

Based on the fundamental special Lie algebra , some semi-direct sums are presented. Then, a new semi-direct sum Lie algebra is constructed. The method presented in this paper can be used to obtain other higher-dimensional Lie algebra. Making use of the above Lie algebra, three integrable couplings of the new Bargmann type lattice hierarchy are obtained.

In the frame work of the nearest-neighbor harmonic spring model, we calculate the phonon spectra by means of the transfer matrix method and investigate the influences of the spring constants, the periodicity, the degree of defect for a periodic chain and the length of a chain on the phonon spectra of Fibonacci chain. It is found that for a certain generation chain the range of the phonon spectra enlarges from the low- to high-frequency zone with the increment of the parameter λ, and when the structure of a chain is certain, the spectra range decreases and more and more phonon states with higher frequencies disappear with the increment of generation. Consequently, when the chain tends to be infinite, there only exist very few phonon states with low-frequency. On the other hand, for a certain Fibonacci chain, phonon states with high-frequency can be formed only when λ is larger than the corresponding critical value.

Thermal hysteresis in resistivity and magnetization of Pr_0.65Ca_0.35-xSr_xMnO₃(x = 0–0.35) manganites has been systematically studied to establish the interplay of their charge and spin-ordering. The increasing Sr concentration (x) transforms the charge-ordered (CO)/antiferromagnetic (AFM) insulating system (for x = 0) into a mixed-phased one (for x = 0.1) with sharp metal–insulator (MI) transition and finally leads to a ferromagnetic (FM) metallic (for x = 0.35) system. It has been found that the interplay of charge and spin-ordering is higher in mixed-phased state and the thermal hysteresis loop area is bigger. It increases with the increase of sharpness of MI transition. Interplay of charge and spin-ordering decreases with the increase of either CO/AFM insulating or FM metallic phase and is almost absent in completely CO/AFM insulating (with x = 0) or FM metallic (with x = 0.35) states bringing about zero thermal hysteresis loop.