文档介绍：
GaAs 中轻、重空穴对电子自旋相干动力学
的影响#
滕利华,牟丽君*
5
10
15
20
(青岛科技大学,数理学院, 山东青岛 266061)
摘要:研究了 低温下、本征 GaAs 高过超能量态电子自旋相干动力学的浓度依赖,发
现当光子能量为 , 载流子浓度较大时电子自旋相干量子拍的相位翻转 180 度. 理论计
算表明量子拍的相位翻转为区分轻、重空穴系统提供了重要依据,当载流子浓度较大时,量
子拍的振幅主要起源于重空穴价带-导带跃迁,反之,量子拍的振幅主要起源于轻空穴价带
-导带跃迁。在轻空穴价带-导带系统实验测得的电子自旋相干弛豫时间明显大于在重空穴
价带-导带系统测得的电子自旋相干弛豫时间,说明轻、重空穴对电子自旋相干弛豫动力学
有不同影响。
关键词:圆偏振光抽运-探测光谱;自旋相干动力学;浓度依赖;GaAs
中图分类号:O473
Effect of light and heavy hole on spin coherence dynamics of
electron in GaAs
Teng Lihua, Mu Lijun
(School of Mathematics and Physics, Qingdao University of Scienced and Technology, Qingdao,
266061)
Abstract:
Time-resolved circularly polarized pump-probe spectroscopy is used to study the
carrier density dependence of the electron-spin coherence dynamics in intrinsic GaAs at . It is
found that the phase of the quantum beats is altered by 180 degree when the carrier density is
25
30
35
40
increased with the photon energy of . Theoretical calculation shows that the phase reversal
of quantum beats provides the key information to distinguish the heavy hole and light hole
systems, when the carrier density is large, the quantum beats mainly originates from the heavy
hole valance band-conduction band transitions, otherwise, the quantum beats mainly originates
from the light hole valance band-conduction band transitions, thus spin coherence dynamics in
heav