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The linear and nonlinear optical absorption via one and two-photon processes in the finite symmetric parabolic quantum well (FSPQW) under the applied magnetic field have been studied numerically for typical GaAs/Ga x Al 1− x As. The analytical expression of the magneto-optical absorption coefficient (MOAC) is obtained by relating it to the transition probability for the absorption of photons. The effects of the magnetic field, the temperature, and the well width on MOAC and full-width at half-maximum (FWHM) are investigated. Results reveal that MOAC and FWHM are monotonic functions of these factors in both one and two-photon absorption processes. Obtained results also show that the magneto-optical properties of FSPQW can be controlled by changing these parameters. This suggests a new capacity for magneto-optical device applications. [ABSTRACT FROM AUTHOR]

• The influence of the laser width on the possibility of generation Bell states is considered. • Exact formulas determining complex probability amplitudes for the system were obtained. • Probabilities to the system exist in the Bell states are shown. • The parameter b 0 is an important parameter to play the controlling role position and value of probabilities the system. We research on a Kerr nonlinear coupler comprising two nonlinear oscillations linearly couple with each other. This coupler is pumped by external classical fields, which are supposed to be decomposed into two parts: a coherent part and a randomly fluctuating chaotic component (white noise). We can see that the quantum evolution of the pumped couplers is closed in a Hilbert space of two-qubit spanned by single-photon and vacuum states only. Hence, the pumped couplers can treat as a system of two-qubit. Analysis of time evolution of the quantum entanglement shows that maximally entangled states can be generated in the system and compare these results with that obtained previously by other authors. [ABSTRACT FROM AUTHOR]

Abstract The anharmonic correlated Debye model has been developed to investigate the thermal disorder in B2-type FeAl intermetallic alloy. We derive analytical expressions of the bond-stretching force constants, the Debye temperature and frequency, the atomic mean-square displacement and the first three extended X-ray absorption fine structure (EXAFS) cumulants. Numerical calculations of these thermodynamic quantities have been performed for B2-type Fe-40 at.%Al up to temperature 1300 K using the Morse potential whose parameters were derived within the Möbius lattice inversion scheme. Our research shows that the anharmonicity contributions of thermal lattice vibrations are important to the EXAFS cumulants at high temperature. The theoretical predictions are compared with available experimental data when possible to verify the developed anharmonic correlated Debye model. Highlights • Anharmonic correlated Debye model has been developed for B2-FeAl alloy. • The thermal disorder and anharmonicity in B2-FeAl have been investigated. • Parallel and perpendicular mean-square relative displacements are considered. [ABSTRACT FROM AUTHOR]

The anharmonic contributions and pressure effects on extended X-ray absorption fine structure (EXAFS) Debye-Waller factor of platinum metal have been investigated up to 900 K and 14 GPa within the anharmonic correlated Debye model. Parameters of interatomic potential have been derived under the second-moment approximation of tight binding scheme. Our calculations of the EXAFS Debye-Waller factor and anharmonic effective potential are compared with those of experiments showing the good and reasonable agreements. We have shown in detail that the anharmonicity of the thermal vibration of atoms give an important contribution to EXAFS Debye-Waller factor at high temperature. And the increasing of pressure will depress the EXAFS amplitude through the reduction of atomic mean-square relative displacement characterizing the Debye-Waller factor. [ABSTRACT FROM AUTHOR]

The anharmonic effects of gold in extended X-ray absorption fine structure (EXAFS) have been investigated through the consideration of the first four EXAFS cumulants up to temperature 800 K within the anharmonic correlated Debye model. The interatomic potential between two intermediate atoms has been described by the second-moment approximation to the tight-binding model and its parameters were determined from first-principles calculations. Our results of the first four EXAFS cumulants and anharmonic effective potential are compared with those of experiments showing the good and reasonable agreements. We have shown in detail that the anharmonicity contributions of the thermal vibration of atoms are important to EXAFS cumulants at high temperature. [ABSTRACT FROM AUTHOR]