Université de Toulouse, INSA-CNRS-UPS, LPCNO, France.
Phys Rev Lett. 2011 Sep 23;107(13):136604. doi: 10.1103/PhysRevLett.107.136604. Epub 2011 Sep 19.
The electron spin dynamics in (111)-oriented GaAs/AlGaAs quantum wells is studied by time-resolved photoluminescence spectroscopy. By applying an external electric field of 50 kV/cm a two-order of magnitude increase of the spin relaxation time can be observed reaching values larger than 30 ns; this is a consequence of the electric field tuning of the spin-orbit conduction band splitting which can almost vanish when the Rashba term compensates exactly the Dresselhaus one. The measurements under a transverse magnetic field demonstrate that the electron spin relaxation time for the three space directions can be tuned simultaneously with the applied electric field.
通过时间分辨光致发光光谱研究了（111）取向 GaAs/AlGaAs 量子阱中的电子自旋动力学。通过施加 50 kV/cm 的外电场，可以观察到自旋弛豫时间增加两个数量级，达到超过 30 ns 的值；这是由于自旋轨道导带分裂的电场调谐的结果，当 Rashba 项完全补偿 Dresselhaus 项时，自旋轨道导带分裂几乎可以消失。在横向磁场下的测量表明，三个空间方向的电子自旋弛豫时间可以通过施加的电场同时进行调节。
