A new approximating method for Holstein model

作者:Ren XueZao*; Liao Xu; Li Lei; Wang KeLin
来源:Science China Physics,Mechanics & Astronomy, 2010, 53(1): 44-48.
DOI:10.1007/s11433-010-0104-3

摘要

A new approach-the method of coherent state orthogonal expansion is developed for one-dimensional Holstein model. In zeroth order approximation, the formula of ground state energy is deduced analytically and the solutions in strong- and weak-coupling limits are obtained correctly. When the trial wave-function of ground state is expanded to the second order, the obtained ground state energy agrees quite well with that calculated by numerical method in all coupling regimes. The present approach can be easily generalized to the situations of higher dimensions and more electrons.

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