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arXiv 1408.5322cond-mat.mes-hall
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自旋轨道相互作用系数的直接确定和自旋螺旋对称性的实现

Direct determination of spin orbit interaction coefficients and realization of the persistent spin helix symmetry

A. Sasaki, S. Nonaka, Y. Kunihashi, M. Kohda, T. Bauernfeind, T. Dollinger, K. Richter, J. Nitta

摘要:

自旋轨道相互作用在凝聚态物质的各个领域都起着至关重要的作用,包括马约拉纳费米子、拓扑绝缘体、量子信息和自旋电子学的研究。在Ⅲ V族锌异质结半导体中,Rashba和Dresselhaus两种自旋轨道相互作用作为不同方向的有效磁场作用于电子自旋。它们分别由系数α和β表征。当α等于β时,实现了所谓的持久自旋螺旋对称性。在这种情况下,相对于自旋旋转的不变性是实现即使在存在的自旋轨道相互作用,这意味着强烈增强的自旋寿命的空间周期性自旋模式。现有的方法来评估阿尔法/贝塔需要拟合分析,往往包括模糊的参数使用。在这里,我们实验证明了一个简单的和拟合参数的自由技术,以确定α/β,并推导出α和β的绝对值。该方法是基于检测的有效磁场方向和强度所引起的两个自旋轨道相互作用。此外,我们观察到持续的自旋螺旋对称性的门调谐。

英文摘要:

The spin orbit interaction plays a crucial role in diverse fields of condensed matter, including the investigation of Majorana fermions, topological insulators, quantum information and spintronics. In III V zinc blende semiconductor heterostructures, two types of spin orbit interaction, Rashba and Dresselhaus act on the electron spin as effective magnetic fields with different directions. They are characterized by coefficients alpha and beta, respectively. When alpha is equal to beta, the so called persistent spin helix symmetry is realized. In this condition, invariance with respect to spin rotations is achieved even in the presence of the spin orbit interaction, implying strongly enhanced spin lifetimes for spatially periodic spin modes. Existing methods to evaluate alpha/beta require fitting analyses that often include ambiguity in the parameters used. Here, we experimentally demonstrate a simple and fitting parameter free technique to determine alpha/beta and to deduce the absolute values of alpha and beta. The method is based on the detection of the effective magnetic field direction and the strength induced by the two spin orbit interactions. Moreover, we observe the persistent spin helix symmetry by gate tuning.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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