GaAs中电子g因子的温度和能量依赖性的飞秒激光吸收量子拍研究  

Studies on the temperature and energy dependence of g factor in GaAs by femtosecond laser absorption quantum beats

作　　者：徐海红[1] 焦中兴[1] 刘晓东[1] 雷亮[1] 文锦辉[1] 王惠[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,物理系广州市510275

出　　处：《物理学报》2006年第5期2618-2622,共5页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:60378006;10274170);国家自然科学基金重大项目(批准号:60490290);广东省自然科学基金(批准号04009736);科技厅重点引导项目(批准号:2004B10101006);高等学校博士学科点基金(批准号:20050558030)资助的课题~~

摘　　要：采用时间分辨椭圆偏振光抽运-探测光谱研究磁场作用下本征GaAs中电子自旋弛豫动力学,观察到吸收量子拍现象.这种吸收量子拍起源于电子自旋的拉莫尔进动,因而其拍频成为高精度测量电子g因子的一种新方法.利用这种新方法研究了本征GaAs中电子g因子的温度和能量依赖特性,发现g因子随电子的温度和能量增加而增加,但与k·p理论预测相差甚大.基于实验结果拟合,我们给出了一个g因子的温度和能量依赖的经验公式.Time-resolved elliptically polarized pump-probe spectroscopy developed by us is used to study spin relaxation dynamics of electrons in an intrinsic GaAs under an external magnetic field. Absorption quantum beats are observed and attributed to Larmor precession of electron spin around the magnetic field. The frequency of this quantum beat is used as a new method to measure electronic g factor with high accuracy. In this paper, this new method is utilized to investigate the temperature and energy dependence of electronic g factor in the intrinsic GaAs. It is found that electronic g factor increases with the temperature and energy of electrons, which is guitc different from the dependence predicted by k · p theory. An empirical formula is given to describe the temperature and energy dependence of g factor by fitting experimental data.

关 键 词：椭圆偏振光抽运-探测光谱 自旋量子拍 G因子 GAAS 

分 类 号：O472[理学—半导体物理]