Gate-controlled persistent spin helix state in (In,Ga)As quantum wells
Gate-controlled persistent spin helix state in (In,Ga)As quantum wells
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DOI：
10.1103/physrevb.86.081306
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发表时间：
2012-08-27
影响因子：
3.7
通讯作者：
Ganichev, S. D.
中科院分区：
文献类型：
--
作者：
Kohda, M.;Lechner, V.;Ganichev, S. D.
在具有自旋-轨道相互作用（SOI）的层状半导体中，如果Rashba和Dresselhaus SOI项的α和β的强度相等，则预期具有抑制的自旋弛豫的持续自旋螺旋（PSH）状态。在这里，我们展示了门控和检测的PSH在二维电子系统与强大的SOI包括条款立方动量。我们考虑应变的InGaAs/InAlAs量子威尔斯，并首先确定一个比率α/β类似或等于1的nongated结构通过测量的自旋电流和循环光电效应。在门调整Rashba SOI强度在互补磁输运实验中，我们监测到从弱反局域化通过弱本地化弱反局域化，其中弱本地化的出现反映了PSH型状态的完整交叉。相应的数值分析表明，这样的PSH型状态确实普遍存在，即使在强立方SOI的存在下，但不再在α = β。
In layered semiconductors with spin-orbit interaction (SOI) a persistent spin helix (PSH) state with suppressed spin relaxation is expected if the strengths of the Rashba and Dresselhaus SOI terms, alpha and beta, are equal. Here we demonstrate gate control and detection of the PSH in two-dimensional electron systems with strong SOI including terms cubic in momentum. We consider strain-free InGaAs/InAlAs quantum wells and first determine a ratio alpha/beta similar or equal to 1 for nongated structures by measuring the spin-galvanic and circular photogalvanic effects. Upon gate tuning the Rashba SOI strength in a complementary magnetotransport experiment, we monitor the complete crossover from weak antilocalization via weak localization to weak antilocalization, where the emergence of weak localization reflects a PSH-type state. A corresponding numerical analysis reveals that such a PSH-type state indeed prevails even in presence of strong cubic SOI, however no longer at alpha = beta.