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JB Wang

Publications and source records attributed to JB Wang.

9 recordsLinked to original sources

Spin anisotropy for excitation in collisions between two one-electron atoms

The singlet and triplet contributions of excitation cross sections are studied theoretically for collisions between various two one-electron atoms. The spin anisotropy is shown to have a general behavior in the important impact energy range. At low energies triplet cross sections dominate completely over the singlet ones while the opposite is true when the active electron and projectile velocities are comparable. Beyond the matching velocity regime singlet and triplet contributions become identical. We propose a general dynamical interpretation based on the analysis of the time dependency of the electron probability density and probability current density.

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Complex absorbing potential and chebyshev propagation scheme

This work presents a detailed analysis of complex absorbing potentials employed to eliminate reflection or wrap-around of wave packets at numerical grid boundaries. In particular, a limiting value for the maximum propagation time step is derived, beyond which the complex potential may introduce massive errors and the Chebyshev propagation scheme is found to fail.

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Acoustical wave propagator

In this paper, an explicit acoustical wave propagator (AWP) is introduced to describe the time-domain evolution of acoustical waves. To implement its operation on an initial state of wave motion, the acoustical wave propagator is approximated as a Chebyshev polynomial expansion, which converges to machine accuracy. The spatial gradient in each polynomial term is evaluated by a Fourier transformation scheme. Analysis and numerical examples demonstrated that this Chebyshev-Fourier scheme is highly accurate and computational effective in predicting time-domain acoustical wave propagation and scattering.

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