Inversion-asymmetry-induced spin splitting observed in the quantum oscillatory magnetization of a two-dimensional electron system
Inversion-asymmetry-induced spin splitting observed in the quantum oscillatory magnetization of a two-dimensional electron system
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DOI：
10.1103/physrevb.79.125330
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发表时间：
2009-03
影响因子：
3.7
通讯作者：
M. Wilde;D. Reuter;C. Heyn;A. Wieck;D. Grundler
中科院分区：
文献类型：
--
作者：
M. Wilde;D. Reuter;C. Heyn;A. Wieck;D. Grundler
研究了结构反转不对称的AlGaAs/GaAs异质结中二维电子系统的De Haas2 1van Alphen(DHvA)效应。用30mK的扭矩磁测量发现，在大倾角下，磁量子振荡呈现拍频模式。我们将这些特征归因于自旋-轨道相互作用引起的费米面的自旋分裂。20多年前，拜奇科夫和拉什巴就已经预测到dHvA效应中的这种跳动模式，但之前没有报道过。从磁化强度M的节拍节点位置，我们估计零场自旋分裂约为$200\Text{}\EnsureMath{\Mu}\Text{ev}$。有趣的是，我们发现dHvA信号中的特征相位变化伴随着dHvA振荡的不连续跳跃从高场向低场的移动。这一观察结果出乎意料，需要进一步的理论解释。
We have investigated the de Haas\char21{}van Alphen (dHvA) effect of a two-dimensional electron system in an AlGaAs/GaAs heterojunction which exhibited structure inversion asymmetry. Using torque magnetometry at 30 mK the magnetic quantum oscillations are found to display beating patterns under large tilt angles. We attribute these features to spin splitting of the Fermi surface due to spin-orbit interaction. Such beating patterns in the dHvA effect have been predicted by Bychkov and Rashba more than two decades ago but have not been reported before. From the beat node positions in the magnetization $M$ we estimate the zero-field spin splitting to be about $200\text{ }\ensuremath{\mu}\text{eV}$. Interestingly we find characteristic phase changes in the dHvA signal accompanied by a shift of the discontinuous jump in $M$ from the high-field to the low-field side of the dHvA oscillations. This observation is unexpected and needs further theoretical explanation.