InAs／GaAs应变异质界面能带排列的极端应变效应

Exceeding Strain-induced Effects on the Electronic Properties of InAs/GaAs Strained-layer Superlattices

建议用一种基于超晶格自洽超原胞计算的形变势方法来确定ＩｎＡｓ／ＧａＡｓ应变异质界面的能带排列情况。该方法全面考虑了界面电荷、弹性应变以及自旋－轨道耦合等因素对能带排列的影响。结果表明，ＩｎＡｓ／ＧａＡｓ异质界面的能带排列具有极端显著的应变效应，通过人工控制其平面内晶格常数（可由选择不同的衬底来实现），可使其成为Ⅰ型，Ⅱ型超晶格或金属。此应变效应主要来源于单轴应力及其与自旋－轨道分裂的耦合，而流体静压和界面电荷的作用则相对很小．本文对以ＧａＡｓ为衬底情况下的计算结果与Ｘ射线光发射实验数据相一致。

A theoretical method called selfconsistent deformation potential method issuggested to detemine the band lineup at InAs/GaAs heterointerfaces under different strain con-ditions. It is shown that the InAs/GaAs system has a exceeding strain effect on its electronicproperties, and can be modulated to become a type Ⅰ or type Ⅱ superlattice or a metal by control-ling artificially its shain condition. The exceeding strain effect is mainly due to the uniaxis stressand its interaction with the spin-orbit splitting,but affected little by the hydrostatic pressure andinterface charge transfer,Present result for a GaAs-substrated lnAs/GaAs system is in gcod a-greement with the experimental datum from X-ray photoemission spectroscopy;