半导体中的自旋弛豫--从体材料到量子阱、量子线、量子点

本文对半导体中的自旋弛豫过程给出一个简要的回顾,介绍了半导体材料从体材料到量子阱、量子线、量子点不同维数的结构中各种自旋弛豫过程,主要关注了自旋去相位和相干控制。对于不同材料中的各种弛豫机制,关注的重点在于如何能够在实验上以一种可以控制的方式来改变可调参数从而达到控制自旋弛豫过程。这些参数主要有电场、磁场、温度、应变、有效g因子等等。本文的组织上,首先介绍研究前景,第1部分简要介绍了自旋弛豫的四种机制。第2部分按照维数的不同将半导体中自旋弛豫分为3个部分:体材料、量子阱、量子线、量子点,在每一部分中又基本上按照电子、空穴、激子的顺序进行了简要的总结:对于不同的载流子,考虑了自旋弛豫对可调参数的依赖关系。这些结果要么试图解释了已有的实验结果,要么从理论上给出预言从而给实验指明了方向,为室温下可以使用的自旋电子学器件设计提供了依据,为固态量子计算和量子信息处理铺平了道路。最后简单地给出展望。

SPIN RELAXATION IN SEMICONDUCTORS:FROM BULK MATERIALS TO QUANTUM WELLS,QUANTUM WIRES, QUANTUM DOTS

In this paper,a brief review on spin relaxation in semiconductors is given. All kinds of spin relaxation processes in different dimensions of semiconductors,including bulk materials,quantum wells,quantum wires and quantum dots,are given.The focus is put on spin dephasing and coherent control.Among all kinds of spin relaxation processes in many different materials,the key problem is how to change the parameters,such as electric field,magnetic field,temperature,strain,effective g parameter and so on,to control spin relaxation in a controllable way.In the organization of this paper,first a background is given;in section 2,a brief introduction of four spin relaxation mechanisms;in section 3, according to the dimension,spin relaxation in semiconductor materials are divided into four sections: bulk materials,quantum wells,quantum wires and quantum dots.In each section,the review cover the three carriers: electrons,holes and excitons.The dependences of spin relaxation for different carriers on controllable parameters are given.The results either try to explain the experimental results,or try to give predicts in theory to lead the way for experiments,helping design room temperature using spintronics devices and opening the way to solid quantum computation and quantum information process.A outlook is given at the end.