International Journal of Modern Physics B

Effects due to the proximity of a superconductor has motivated a lot of research work in the last several decades both from theoretical and experimental point of view. In this review, we are going to describe the physics of systems containing normal metal-superconductor interface. Mainly we discuss transport properties through such hybrid structures. In particular, we describe the effects of electron–electron interaction on transport through such superconducting junction of multiple one-dimensional quantum wires. The latter can be described in terms of a non-Fermi liquid theory called Luttinger liquid. In this review, from the application point of view, we also demonstrate the possible scenarios for production of pure spin current and large tunneling magnetoresistance in such hybrid junctions and analyze the influence of electron–electron interaction on the stability of the production of pure spin current.

By using the reed-vibration mechanical spectroscopy for liquids (RMS-L), we measured the complex Young's modulus of dimethyl phthalate (DP) during a cooling and heating circulation starting from room temperature at about 2 KHz. The results show that there is no crystallization in the cooling supercooled liquid (CSL) of DP, but a crystallization process in the heating supercooled liquid (HSL) after the reverse glass transition. Based on the measured modulus, crystal volume fraction (v) during the HSL crystallization was calculated. Moreover, the Avrami exponent (n) was obtained according to the JJMA equation and v data. In view of n versus temperature and v, the nucleation dynamics was analyzed, and especially, there has already existed saturate nuclei in DP HSL before the crystallization. Furthermore, the authors inferred that the nuclei are induced by the random frozen stress in the glass, but there is no nucleus in CSL. The above results indicated that RMS-L might provide a new way to measure and analyze the crystallization of liquids.

The mechanism and properties of electron transfer along protein molecules at finite temperature T ≠ 0 in the life systems are studied using nonlinear theory of bio-energy transport and Green function method, in which the electrons are transferred from donors to acceptors in virtue of the supersound soliton excited by the energy released in ATP hydrolysis. The electron transfer is, in essence, a process of oxidation–reduction reaction. In this study we first give the Hamiltonian and wavefunction of the system and find out the soliton solution of the dynamical equation in the protein molecules with finite temperature, and obtain the dynamical coefficient of the electron transfer. The results show that the speed of the electron transfer is related to the velocity of motion of the soliton, distribution of electrons in the donor and acceptor as well as the interaction strength among them. We finally concluded the changed rule of electric current, arising from the electron transfer, with increasing time. These results are useful in molecular and chemical biology.

A two-level system interacting with a heat bath is considered. For simplicity the electron is assumed to interact with only two modes of the heat bath. The ground state energy of this system is obtained using a variational approach involving a series of canonical transformations. The present results are found to be more accurate than the previously reported variational results.

We theoretically study the static and dynamic transport properties of Mott–Gurney diodes based on semiconducting single-walled zigzag carbon nanotubes (CNTs). The electric field and velocity distribution of the diode under dc voltage is obtained by solving the steady-state drift-diffusion equations, which involve the negative differential velocity. The current–voltage characteristic of CNT diode exhibits a distinctive positive differential resistance. The high-frequency impedance is calculated with the small-signal analysis method. A major feature of the proposed CNT diode is that the bias- and tube index-dependent impedance show several negative windows in terahertz frequency range despite the positivity of the dc differential resistance. This property makes the CNT-based Mott–Gurney diode a promising candidate for the generation and amplification of terahertz signals within the desired frequency region.

In this paper, we study the ground state of a one-dimensional exactly solvable model with a spiral order. While the model's energy spectrum is the same as the one-dimensional transverse field Ising model, its ground state manifests a spiral order with various periods. The quantum phase transition from a spiral-order phase to a paramagnetic phase is investigated in the perspectives of quantum information science and mechanics. We show that the modes of the ground-state fidelity and its susceptibility can identify the change of periodicity around the critical point. We also study the spin torsion modulus which defines the coefficient of the potential energy stored under a small rotation. We find that at the critical point, it is a constant; while away from the critical point, the spin torsion modulus tends to zero.

This work is concerned with the general methods for the function projective synchronization (FPS) of chaotic (or hyperchaotic) systems. The aim is to investigate the FPS of different chaotic (hyper-chaotic) systems with unknown parameters. The adaptive control law and the parameter update law are derived to make the states of two different chaotic systems asymptotically synchronized up to a desired scaling function by Lyapunov stability theory. The general approach for FPS of Chen hyperchaotic system and Lü system is provided. Numerical simulations are also presented to verify the effectiveness of the proposed scheme.

Projective synchronization between two nonlinear systems with different dimension was investigated. The controllers were designed when the dimension of drive system greater than the one of response system. The opposite situation also was discussed. In addition, we found an approach to control the chaotic (hyperchaotic) system to exhibit the behaviors of hyperchaotic (chaotic) system. The numerical simulations were implemented on different chaotic (hyperchaotic) systems, and the results indicate that our methods are effective.

The selection and breakup of spiral wave in a coupled network is investigated by imposing Gaussian colored noise on the network, respectively. The dynamics of each node of the network is described by a simplified Chua circuit, and nodes are uniformly placed in a two-dimensional array with nearest-neighbor connection type. The transition of spiral wave is detected by changing the coupling intensity, intensity and correlation time τ in the noise. A statistical variable is used to discern the parameter region for breakup of spiral wave and robustness to external noise. Spiral waves emerge in the network when the network with structure of complex-periodic and chaotic properties. It is found that asymmetric coupling can induce deformation of spiral wave, stronger intensity or smaller correlation time in noise does cause breakup of the spiral wave.