Advanced Technology Institute, University of Surrey, Guildford GU2 7XH, UK.
J Phys Condens Matter. 2011 Jan 26;23(3):035801. doi: 10.1088/0953-8984/23/3/035801. Epub 2011 Jan 5.
We report the optical measurement of the spin dynamics at elevated temperatures and in zero magnetic field for two types of degenerately doped n-InSb quantum wells (QWs), one asymmetric (sample A) and one symmetric (sample B) with regards to the electrostatic potential across the QW. Making use of three directly determined experimental parameters: the spin lifetime, τ(s), the sheet carrier concentration, n, and the electron mobility, μ, we directly extract the zero-field spin splitting. For the asymmetric sample where the Rashba interaction is the dominant source of spin splitting, we deduce a room temperature Rashba parameter of α = 0.09 ± 0.1 eV Å which is in good agreement with calculations and we estimate the Rashba coefficient α(0) (a figure of merit for the ease with which electron spins can be modulated via an electric field). We review the merits/limitations of this approach and the implications of our findings for spintronic devices.
我们报告了在高温和零磁场下两种类型的简并掺杂 n-InSb 量子阱（QW）的自旋动力学的光学测量结果，这两种量子阱在 QW 中的静电势方面一个是不对称的（样品 A），一个是对称的（样品 B）。利用三个直接确定的实验参数：自旋寿命 τ(s)、薄片载流子浓度 n 和电子迁移率 μ，我们直接提取了零场自旋分裂。对于不对称样品，其中 Rashba 相互作用是自旋分裂的主要来源，我们推断出室温下的 Rashba 参数为 α = 0.09 ± 0.1 eV Å，这与计算结果非常吻合，我们还估计了 Rashba 系数 α(0)（衡量通过电场调制电子自旋的容易程度的一个指标）。我们回顾了这种方法的优点/局限性以及我们的发现对自旋电子器件的影响。
