Zero-field spin precession dynamics of high-mobility two-dimensional electron gas in persistent spin helix regime
Zero-field spin precession dynamics of high-mobility two-dimensional electron gas in persistent spin helix regime
复制标题
持续自旋螺旋状态下高迁移率二维电子气的零场自旋进动动力学
DOI：
10.1103/physrevb.101.094438
复制
发表时间：
2020
影响因子：
3.7
通讯作者：
Miyajima Kensuke
中科院分区：
文献类型：
--
作者：
Ishihara Jun;Kitazawa Go;Furusho Yuya;Ohno Yuzo;Ohno Hideo;Miyajima Kensuke
研究了调制掺杂（001）GaAs/AlGaAs量子阱中高迁移率二维电子气（2DEG）在接近持续自旋螺旋（PSH）态时的自旋轨道（SO）有效磁场诱导自旋进动.在零外磁场下，观察到了SO场诱导的自旋振荡信号。当光激发载流子密度与2DEG密度相比足够小时，通过分析PSH区域中的旋进频率来获得空间域中的自旋旋进长度。使用散射含时自旋动力学模拟很好地再现了自旋动力学的激发密度依赖性。我们发现，在光激发的载流子的增加的结果在从弹道运动到扩散运动的过渡，导致自旋扩散系数的降低。
We investigated the spin-orbit (SO) effective magnetic-field-induced spin precession of a high-mobility two-dimensional electron gas (2DEG) in a modulation-doped (001) GaAs/AlGaAs quantum well close to the persistent spin helix (PSH) state. The oscillating spin signal induced by the SO fields in zero external magnetic fields was clearly observed. When the photoexcited carrier density is sufficiently small compared with the 2DEG density, the spin precession length in the space domain was obtained by analyzing the precession frequency in the PSH regime. The excitation density dependence of the spin dynamics was reproduced well using the scattering time-dependent spin dynamics simulation. We revealed that the increase in the photoexcited carriers results in a transition from ballistic motion to diffusive motion, leading to a decrease in the spin-diffusion coefficient.