立方半导体光学声子形变势的LMTO计算方法

本文采用LMTO-ASA能带计算方法,以冻结声子的近似模型,计算了GaP和GaAs的长波声子光学模单声子形变势.讨论了几种不同的计算方案并同非局域赝势法(NEPM)的计算结果进行了比较.研究表明,LMTO-ASA的各计算方案中与NEPM方法的结果最为接近的是空球跟随相应原子球位移的冻结势计算方案,其结果与实验结果的符合程度不亚于NEPM方法.从而为闪锌矿结构半导体长光学声子形变势的计算提供了一种可行的从头计算方法.

LMTO Calculation of the Optical-Phonon Deformation Potentials of Cubic Semiconductors

The optical-phonon deformation potentials of cubic semicoductor GaP and GaAs havebeen investigated by LMTO-ASA approach within the frozen-phonen approximation.Some of thedifferent treatments in frame of LMTO method are examined and compared with the nonlocalempirical pseudopotential method (NEPM).The investigation indicates that the results of fro-zen-potential.model,in which the displacement of empty spheres is synchronized with the vibra-tion of atomic spheres, are closest to that of the NEPM in a variety of LMTO treatments.Theagreement between this approach and experiment is not inferior to one of the NEPM,thus pro-viding the optical deformation potentials of the zinc-blende semiconductors with a feasible abinitio calculation.