Anisotropic expansion of drifting spin helices in GaAs quantum wells
Anisotropic expansion of drifting spin helices in GaAs quantum wells
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GaAs量子阱中漂移自旋螺旋的各向异性膨胀
DOI：
10.1103/physrevb.103.035429
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发表时间：
2021
影响因子：
3.7
通讯作者：
Betz M.
中科院分区：
文献类型：
--
作者：
Anghel S.;Poshakinskiy A. V.;Schiller K.;Passmann F.;Ruppert C.;Tarasenko S. A.;Yusa G.;Mano T.;Noda T.;Betz M.
利用时间分辨磁光克尔显微术研究了GaAs量子阱威尔斯中电子自旋螺旋线在面内外电场中的漂移。不同激发功率下测量的自旋分布的演变表明，对于短延迟时间和较高的激发功率，自旋螺旋漂移减慢，而其包络变得各向异性。该效应被理解为由于电子与激发点内的非平衡空穴碰撞而导致的电子气迁移率的局部降低，并且在动力学理论框架中被很好地再现。对于较大的延迟时间，当构成自旋螺旋和非平衡空穴的电子被电场分开时，自旋螺旋漂移加速，迁移率再次达到其未扰动值。
The drift of electron spin helices in an external in-plane electric field in GaAs quantum wells is studied by means of time-resolved magneto-optical Kerr microscopy. The evolution of the spin distribution measured for different excitation powers reveals that, for short delay times and higher excitation powers, the spin helix drift slows down while its envelope becomes anisotropic. The effect is understood as a local decrease of the electron gas mobility due to electron collisions with nonequilibrium holes within the excitation spot and is reproduced well in the kinetic theory framework. For larger delay times, when the electrons constituting the spin helix and nonequilibrium holes are separated by an electric field, the spin helix drift accelerates and the mobility reaches its unperturbed value again.