中文摘要：

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.

英文摘要：

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.