本征GaAs量子阱中电子自旋扩散输运的时-空分辨吸收光谱研究  

Study of electron spin diffusion transport in intrinsic GaAs quantum wells by time-and space-resolved absorbtion spectroscopy

作　　者：余华梁[1] 张秀敏[1] 滕利华[1] 文锦辉[1] 林位株[1] 赖天树[1] 

机构地区：[1]中山大学光电材料与技术国家重点实验室 物理科学与工程学院,广州510275

出　　处：《物理学报》2009年第5期3543-3547,共5页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:60490295,60678009,10674184,10874247);高等学校博士学科点专项科研基金(批准号:20050558030)资助的课题~~

摘　　要：发展了一种时-空分辨圆偏振光抽运-探测光谱及其理论,并用于本征GaAs量子阱中电子自旋扩散输运的实验研究.获得室温下本征GaAs量子阱中的"自旋双极扩散系数"为Das=37.5±15cm2/s.此结果比用自旋光栅法测量到的掺杂GaAs量子阱中电子自旋扩散系数小.解释为是由于"空穴库仑拖曳"效应减慢了电子自旋波包的扩散输运.A time- and space-resolved circularly polarized pump-probe spectroscopy and its theory are developed, and are used experimentally to study electron spin diffusion transport in intrinsic GaAs quantum wells. The ambipolar spin diffusion coefficient of Das = 37.5 ＋ 15 cm^2/s is obtained at room temperature, and is smaller than that in a doped GaAs quantum well obtained by spin grating. The difference is explained based on ＂hole Coulomb drag＂ effect which slows the diffusion transport of electron spin packet.

关 键 词：时-空分辨抽运-探测光谱 电子自旋扩散 GAAS量子阱 

分 类 号：O472.3[理学—半导体物理]