我们实验研究了(110)-GaAs量子阱中光生载流子对电子自旋弛豫的影响。通过测量量子阱的荧光寿命和光学吸收计算,我们能得到不同泵浦光功率下的带间吸收所产生的空穴浓度;相对应地,通过双色磁光科尔旋转技术,我们测量了该GaAs量子阱中电子自旋的动力学过程。结合两者,我们得到了电子自旋弛豫速率与空穴浓度的关系。实验结果表明电子自旋弛豫速率与空穴浓度呈线性依赖关系,验证了Bir-Aronov-Pikus机制主导该体系的电子自旋弛豫。

The effect of optical carriers on electron spin relaxation is experimentally investigated in a (110)-orientated GaAs／(Al,GaAs) quantum well by means of two-color time-resolved Kerr rotation(TRKR). The density of excited optical carriers is estimated by measuring the photoluminescence dynamics and calculating the optical absorption. By determining the corresponding spin relaxation rate from TRKR,we can obtain the relation between the spin relaxation rate and the optically generated carrier density. By comparing the theoretical value of the relaxation rate contributed by the Bir-Aronov-Pikus mechanism and the experimentally determined value,we conclude the spin relaxation in this study is dominated by optically generated holes.