Modern Physics Letters B

In this letter, we propose a novel information-geometric characterization of chaotic (integrable) energy level statistics of a quantum antiferromagnetic Ising spin chain in a tilted (transverse) external magnetic field. Finally, we conjecture our results might find some potential physical applications in quantum energy level statistics.

The segregation of Cu atoms in the Cu/Ni multilayers was investigated by means of the full-potential linearized augmented plane-wave method with the generalized-gradient approximation formula. We investigated the segregation of Cu atoms when the Cu/Ni slab is along the (001) and (111) directions, respectively. The results obtained show that at most one-layer Cu atoms can segregate to the Ni surface when Ni films are deposited on the Cu substrate and the segregation of Cu atoms is not sensitive to the orientation of the Cu/Ni slab surface. The result of Cu segregation is to reduce the vacuum effect.

By using the variational identity, the Hamiltonian structures of the C-KdV hierarchy, integrable couplings of C-KdV hierarchy, (2+1)-dimensional C-KdV hierarchy as well as the multi-component integrable system are obtained.

In this paper, we propose a deviation model and consider the transmission property of Thue–Morse (TM) multilayers with deviations. It is found that at the central wavelength for very simple systems, the transmission coefficients (TCs) have nothing to do with the deviation of a machine, but when a multilayer system becomes more complex, one should use the most precise machine in order to make the system possess the designed value of TC. However, if superlattices become more complicated, one may choose a machine with a suitable relative error, but not the most accurate machine, to manufacture a perfect system. Additionally, after the number of layers exceeds some critical value, the very sophisticated optical superlattices could only be manufactured by very precise machines. The results would be useful for designing and manufacturing thin films of optical superlattices.

The entanglement characteristics of the three-qutrit spin-one Heisenberg chain in the presence of one impurity site is investigated by using the concept of negativity. The results show that the existence of impurity can lead to an enhancement of both bipartite and pairwise entanglement for certain ranges of the impurity parameter, and the amount of entanglement can be controlled and tuned by varying the impurity parameter J₁. The results also show that the thermal fluctuations always suppress the entanglement and as a result there exists a threshold temperature T_th after which the entanglement vanishes. T_th increases as J₁ increases except the case for that of the pairwise negativity which measures entanglement between the two norm spins in the chain.

In this paper, we introduce the self-consistent field approximation to treat with the nonlinear interaction among spin waves. Then temperature-dependent Bogoliubov transformation is introduced to generate a new representation which engenders the transition from the zero temperature to the finite temperature. At last, temperature-dependent quantum fluctuation properties of magnons are discussed in the thermal field. At lower temperature, we find that the fluctuation of spin-component at some given time regions can be below the zero-point fluctuation level of the vacuum state and exhibit a periodical squeezing behavior. In particular, these squeezed effects vanish with the increasing of temperature. These squeezing effects differ from the previous studies.

With the occasional feedback method, the chaotic logistic map is stabilized at an unstable low-periodic orbit. In our method, the qualified feedback coefficient can be obtained through calculation instead of through simulation. Besides, the bifurcation control of the logistic map is studied, and a new scheme is proposed to change the parameter value of any one bifurcation point of this dynamic system optionally. Simulation results show the effectiveness of the methods.

The temperature dependence of photoinduced anisotropy in the photoconductivity of As₂Se₃ and Sb₂S₃ thin films was investigated, in the interval between -50 and 70°C. Our results demonstrate that for both As₂Se₃ and Sb₂S₃ thin films, the anisotropy percentage falls with increasing temperature. We surmise that the aligning effect of the linearly polarized light was diluted with increasing temperature, because the latter induces similar mechanisms to those induced by polarized light, but in an isotropic fashion.

This work is devoted to the investigation of the possibility of controlling of ion motion inside the Paul trap. It has been shown that by proper selection of the parameters controlling the electric fields, stable localization of ions inside the Paul trap is possible. Quantum consideration of this problem is reduced to the investigation of the Mathieu–Schrodinger equation. It has been shown that quantum consideration is appreciably different from the classical one that leads to stronger limitations of the values of the parameters of stable motion. Connection between the problem under study and the possibility of experimental observation of quantum chaos has been shown.