III-V族半导体异质结构二维电子气的自旋输运特性

The spin related transport properties of the two-dimensional electron gases (2DEGs) in III-V semiconductor heterostructures will be investigated by means of magneto-transport measurements. The weak antilocalization (WAL) effects of 2DEGs in III-V semiconductor heterostructures as well as beating patterns in the Shubnikov-de Haas (SdH) oscillatory magnetoresistance induced by zero-field spin splitting will be observed. Meanwhile, the effects of zeeman spin splitting on magnetoresistance in high field range, as well as the effects of electron-electron interaction (EEI) on magnetoresistance in the whole applied magnetic field, will also be observed. The zero-filed spin splitting and spin-orbit coupling constant of 2DEGs will be obtained. The relation between the spin-orbit coupling constant and the 2DEGs parameters will be investigated. The original mechanisms for the spin splitting of the 2DEGs in III-V semiconductor heterostructures will be determined. The results of this research will offer valuable parameters and rules of spin quantum control which are useful for the realization of spintronic devices.

本项目拟采用深低温、强磁场下的磁输运测试方法，研究III-V族半导体异质结二维电子气中的零场自旋分裂及自旋输运特性。主要包括:通过磁输运测试，观察III-V 族半导体异质结二维电子气由零场自旋分裂引起的磁电阻Shubnikov-de Haas(SdH) 振荡的拍频效应和磁电阻在低磁场部分的反弱局域（ weak antilocalization-WAL）效应，以及zeeman效应对磁电阻曲线在高磁场部分的调制，电子电子相互作用量子干涉对整个磁电阻曲线的调制，获得零场自旋分裂能、自旋轨道相互作用常数等参数，以及自旋轨道耦合常数随二维电子气相关参数的变化关系，据此研究III-V族半导体的自旋输运相关特性。这项研究结果不仅能进一步揭示III-V族半导体自旋分裂的物理机制，而且能为利用自旋轨道相互作用的自旋器件的实现提供重要的物理参数及自旋量子调控规律。

本项目采用深低温、强磁场下的磁输运测试方法，研究了III-V族半导体异质结二维电子气中的自旋输运特性。通过磁输运测试，观察III-V 族半导体InGaAs/InAlAs量子阱、AlGaN/GaN异质结二维电子气（two-dimensional electron gas, 2DEG）由零场自旋分裂引起的磁电阻（Shubnikov-de Haas - SdH）振荡的拍频效应和磁电阻在低磁场部分的反弱局域（weak antilocalization-WAL）效应，以及Zeeman效应对磁电阻曲线在高磁场部分的调制，电子电子相互作用（electron-electron interaction, EEI）量子干涉对整个磁电阻曲线的调制。获得了InGaAs/InAlAs量子阱、AlGaN/GaN异质结二维电子气的零场自旋分裂能、自旋轨道耦合常数及有效g因子等参数。InGaAs/InAlAs量子阱、AlGaN/GaN异质结2DEG在大的浓度范围，零场自旋分裂能随载流子浓度的增加有减小趋势，二维电子气自旋分裂机理为本征的非线性Rashba自旋分裂。InGaAs/InAlAs量子阱、AlGaN/GaN异质结二维电子气的自旋轨道相互作用可以通过光照和栅压等外加手段进行调控。