Inelastic light-scattering from spin-density excitations in the regime of the persistent spin helix in a GaAs-AlGaAs quantum well
Inelastic light-scattering from spin-density excitations in the regime of the persistent spin helix in a GaAs-AlGaAs quantum well
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GaAs-AlGaAs 量子阱中持久自旋螺旋区域中自旋密度激发产生的非弹性光散射
DOI：
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发表时间：
2014
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影响因子：
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通讯作者：
C. Schueller
中科院分区：
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作者：
Christoph Schoenhuber;M. Walser;G. Salis;C. Reichl;W. Wegscheider;T. Korn;C. Schueller
利用非弹性光散射研究了具有平衡Rashba和Dresselhaus自旋轨道相互作用强度的非对称掺杂GaAs-AlGaAs单量子阱的亚带内自旋密度激发（SDE）。对于这种独特的对称性，对于二维互易空间的所有波向量，组合自旋-轨道场与量子阱的平面方向[11¯0]平行或反平行。在后向散射几何中，SDE是由自旋分裂子带的自旋翻转子带内跃迁形成的。通过亚带内SDE的分裂，我们直接探测到了由于各向异性自旋轨道场导致的导带自旋分裂。正如预期的那样，如果波矢量垂直于自旋轨道场的方向传递，分裂是非零的，而对于平行波矢量传递，分裂接近于零。提取的自旋轨道强度值和持续自旋螺旋的波长值与先前的自旋螺旋直接空间映射实验结果比较好。
We have investigated the intrasubband spin-density excitation (SDE) in an asymmetrically doped GaAs-AlGaAs single quantum well with balanced Rashba and Dresselhaus spin-orbit interaction strengths by inelastic light scattering. For this unique symmetry, the combined spin-orbit field is either parallel or antiparallel to the [11¯0] in-plane direction of the quantum well for all wave vectors of the two-dimensional reciprocal space. In backscattering geometry, the SDE is formed by spin-flip intrasubband transitions of the spin-split subband. Via the splitting of the intrasubband SDE, we have directly detected the spin splitting of the conduction band due to the anisotropic spin-orbit field. As expected, the splitting is nonzero if a wave vector is transferred perpendicular to the direction of the spin-orbit field and close to zero for a parallel wave-vector transfer. The extracted values for the spin-orbit strength and for the wavelength of a persistent spin helix compare well with results of previous experiments of direct spatial mapping of the spin helix.