瞬态自旋光栅系统的建设及其在自旋输运研究中的应用

Development of the transient spin grating system and its application in the study of spin transport

简要介绍了瞬态光栅系统原理及光路的建设,包括瞬态光栅的产生与探测.采用了外差探测法(heterodyne detection),大大提高了信噪比.利用瞬态自旋光栅系统,研究了(110)方向生长的本征GaAs/AlGaAs单量子阱中自旋输运特性,测得室温下电子自旋的扩散常数Ds=55.1cm/s.

Transient spin grating, as a novel technique in uhrafast magneto-optical laser spectroscopy, is widely used to study the properties of spin transport in semiconductor low-dimensional structures. The principle of transient spin grating and the optical arrangement are described briefly in this paper, which includes the generation and detection of transient spin grating. The signal to noise ratio was significantly enhanced by using heterodyne detection. The spin diffusion coefficient Ds was determined by this technique to be about 55. 1 cm/s in （110） GaAs/AlGaAs single quantum well at room temperature.