Zhu Laipan, Liu Yu, Huang Wei, Qin Xudong, Li Yuan, Wu Qing, Chen Yonghai
Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, People's Republic of China.
Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, National Center for Nanoscience and Technology (NCNST), Beijing, 100083, People's Republic of China.
Nanoscale Res Lett. 2016 Dec;11(1):8. doi: 10.1186/s11671-015-1218-3. Epub 2016 Jan 7.
The spin diffusion and drift at different excitation wavelengths and different temperatures have been studied in undoped InGaAs/AlGaAs multiple quantum well (MQW). The spin polarization was created by optical spin orientation using circularly polarized light, and the reciprocal spin Hall effect was employed to measure the spin polarization current. We measured the ratio of the spin diffusion coefficient to the mobility of spin-polarized carriers. From the wavelength dependence of the ratio, we found that the spin diffusion and drift of holes became as important as electrons in this undoped MQW, and the ratio for light holes was much smaller than that for heavy holes at room temperature. From the temperature dependence of the ratio, the correction factors for the common Einstein relationship for spin-polarized electrons and heavy holes were firstly obtained to be 93 and 286, respectively.
在未掺杂的InGaAs/AlGaAs多量子阱（MQW）中研究了不同激发波长和不同温度下的自旋扩散和漂移。通过使用圆偏振光的光学自旋取向产生自旋极化，并利用逆自旋霍尔效应测量自旋极化电流。我们测量了自旋扩散系数与自旋极化载流子迁移率的比值。从该比值的波长依赖性出发，我们发现在这种未掺杂的多量子阱中，空穴的自旋扩散和漂移与电子的一样重要，并且在室温下轻空穴的该比值远小于重空穴的。从该比值的温度依赖性出发，首次得到自旋极化电子和重空穴的普通爱因斯坦关系的修正因子分别为93和286。
