论文标题
GAAS量子井中的自旋螺旋：电子密度的相互作用，自旋扩散和自旋寿命
Spin helices in GaAs quantum wells: Interplay of electron density, spin diffusion, and spin lifetime
论文作者
论文摘要
为了在自旋扩散，自旋寿命和电子密度之间建立相关性，我们研究了采用时间分辨的磁光光学KERR效应显微镜显微镜，低维GAAS半导体的自旋极化演变托管二维电子气体。结果表明，对于建立最长的旋转旋转时间，当rashba $α$和dresselhaus $β$参数平衡时，用电子密度的变化与持续的自旋螺旋条件相比，散射速率的变化更为重要。更具体地说，无论$α$和$β$线性依赖性对电子密度的依赖性如何，旋转弛豫速率都取决于非单调的电子密度的自旋扩散系数。最长的实验自旋发生在电子密度上，对应于从Boltzmann到Fermi-Dirac统计的过渡，这是预期持续的自旋螺旋的几倍。这些事实突出了电子密度在考虑自旋设备的应用时可能扮演的角色。
To establish a correlation between the spin diffusion, the spin lifetime, and the electron density, we study, employing time-resolved magneto-optical Kerr effect microscopy, the spin polarization evolution in low-dimensional GaAs semiconductors hosting two-dimensional electron gases. It is shown that for the establishment of the longest spin-lifetime, the variation of scattering rate with the electron density is of higher importance than the fulfilling of the persistent spin helix condition when the Rashba $α$ and Dresselhaus $β$ parameters are balanced. More specifically, regardless of the $α$ and $β$ linear dependencies on the electron density, the spin relaxation rate is determined by the spin diffusion coefficient that depends on electron density nonmonotonously. The longest experimental spin-lifetime occurs at an electron density, corresponding to the transition from Boltzmann to Fermi-Dirac statistics, which is several times higher than that when the persistent spin helix is expected. These facts highlight the role the electron density may play when considering applications for spintronic devices.
