Effect of electron-electron scattering on spin dephasing in a high-mobility low-density two-dimensional electron gas
Effect of electron-electron scattering on spin dephasing in a high-mobility low-density two-dimensional electron gas
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DOI：
10.1103/physrevb.77.193307
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发表时间：
2008-04
影响因子：
3.7
通讯作者：
X. Ruan;H. Luo;Yang Ji;Z. Xu;V. Umansky
中科院分区：
文献类型：
--
作者：
X. Ruan;H. Luo;Yang Ji;Z. Xu;V. Umansky
利用时间分辨Kerr旋转技术，在1.5 - 30 K温度范围内研究了GaAs/Al_（0.35）Ga_（0.65）As异质结中高迁移率低密度二维电子气的自旋动力学.结果发现，自旋弛豫/退相时间在0.5 T的磁场下表现出最大值为3.12 ns左右的14 K，这是叠加在一个增加的背景温度上升。最大值的出现归因于在从简并到非简并状态的交叉发生的温度下，电子-电子库仑散射变得最强，因此由于D 'yakonov-Perel'机制的非均匀进动展宽变得最弱。这些结果与最近的理论预测[J. Zhou et al.，Phys. Rev. B 15，045305（2007）]，其验证了电子-电子库仑散射对电子自旋弛豫/退相的重要性。
By utilizing time-resolved Kerr rotation techniques, we have investigated the spin dynamics of a high-mobility low density two-dimensional electron gas in a GaAs/Al0.35Ga0.65As heterostructure in the dependence on temperature from 1.5 to 30 K. It is found that the spin relaxation/dephasing time under a magnetic field of 0.5 T exhibits a maximum of 3.12 ns around 14 K, which is superimposed on an increasing background with rising temperature. The appearance of the maximum is ascribed to that at the temperature where the crossover from the degenerate to the nondegenerate regime takes place, electron-electron Coulomb scattering becomes strongest, and thus inhomogeneous precession broadening due to the D'yakonov-Perel' mechanism becomes weakest. These results agree with the recent theoretical predictions [J. Zhou et al., Phys. Rev. B 15, 045305 (2007)], which verify the importance of electron-electron Coulomb scattering to electron spin relaxation/dephasing.