Modern Physics Letters B

The restrict primitive model of ionic systems is investigated with the integral equation theory. Using the correlation functions calculated in the reference hypernetted chain approximation, we get (i) the Lebowitz lengths at different densities and temperatures, (ii) the density–density correlation lengths along different isochores approaching the spinodal curve from above. The Lebowitz length obtained by us has better agreement with the Monte Carlo simulation results than the generalized Debye–Hückel theory. Along the critical isochore, the Lebowitz length remains finite when approaching the critical temperature from above, while the density–density correlation lengths diverge as t^-1/2 with t = (T - T_s)/T_s, where T_s is the temperature on the spinodal line.

By solving the master equation of Redfield form, we investigate the decoherence of a reduced open-driven qubit. It is shown that when the driving field has not too large frequency to compare to the Rabi frequency of the qubit system, the decoherence of the qubit is affected by the amplitude but not by the frequency of the driving field. We can prolong the decoherence time of the qubit as we choose an appropriate driving field to operate the qubit.

A feasible quantum means for laboratory testing the time-translation theory by Aharonov et al. has previously been proposed. If such tests prove successful, a modified test based on this model is suggested to further investigate anticipated behavioral characteristics of the Many Worlds Interpretation and quantum decoherence.

Problems that cumber the development of the laser propulsion in atmosphere and vacuum are discussed. Based on the theory of interaction between high-intensity laser and materials, such as air and water, it is proved that transport in a water environment can be impulsed by laser. The process of laser propulsion in water is investigated theoretically and numerically. It shows that not only the laser induced plasma shock wave can be used, but also the laser-induced bubble oscillation shock waves and the pressure induced by the collapsing bubble can be used. Many experimental results show that the theory and the numerical results are valid.

We investigate theoretically the spin current and spin current induced electric field in a weak Rashba spin-orbit coupling quantum wire (QW) using a definition for spin current by means of scattering matrix. It is found that there exists two non-zero linear spin current density elements which have oscillation peaks at the center of QW and their strengths can be changed by the number of propagation modes and Rashba constant, respectively. Moreover, the spin current induced electric field has also been calculated and its strength is measurable with present technology with which can be used to detect spin current.

An investigation of the optical properties of a hydrogenic donor in a disc-like parabolic quantum dot with magnetic field has been performed by using the matrix diagonalization method. The optical absorption coefficient between the ground (L = 0) and the first excited state (L = -1) have been examined based on the computed energies and wavefunctions. We found that the linear optical properties of the hydrogenic donor in QDs are strongly affected by the confinement strength and the magnetic field strength.

The LiCo_3/5Fe_2/5VO₄ ceramics has been fabricated by solution-based chemical method. Frequency dependence of the dielectric constant (ε_r) at different temperatures exhibits a dispersive behavior at low frequencies. Temperature dependence of ε_r at different frequencies indicates the dielectric anomalies in ε_r at T_c (transition temperature) = 190°C, 223°C, 263°C and 283°C with (ε_r)_max ~ 5370, 1976, 690 and 429 for 1, 10, 50 and 100 kHz, respectively. Frequency dependence of tangent loss (tan δ) at different temperatures indicates the presence of dielectric relaxation in the material. The value of activation energy estimated from the Arrhenius plot of log(τ_d) with 10³/T is ~(0.396 ± 0.012) eV.

Distinguishing the long-range bonds with the regular ones, the critical temperature of the spin-lattice Gaussian model built on two typical small-world networks is studied. The results show much difference from the classical case, and thus may induce some more accurate discussion on the critical properties of the spin-lattice systems combined with the small-world networks.

By considering a discrete isospectral eigenvalue problem, a hierarchy of lattice soliton equations are derived. The relation to the Toda type lattice is achieved by variable transformation. With the help of Tu scheme, the Hamiltonian structure of the resulting lattice hierarchy is constructed. The Liouville integrability is then demonstrated. Semi-direct sum of Lie algebras is proposed to construct discrete integrable couplings. As applications, two kinds of discrete integrable couplings of the resulting system are worked out.

The capacitance between the origin and any other lattice site in an infinite square lattice of identical capacitors each of capacitance C is calculated. The method is generalized to infinite Simple Cubic (SC) lattice of identical capacitors each of capacitance C. We make use of the superposition principle and the symmetry of the infinite grid.