Spin-orbit scattering visualized in quasiparticle interference
Spin-orbit scattering visualized in quasiparticle interference
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DOI：
10.1103/physrevb.95.115307
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发表时间：
2017-03-15
影响因子：
3.7
通讯作者：
Sasagawa, T.
中科院分区：
文献类型：
--
作者：
Kohsaka, Y.;Machida, T.;Sasagawa, T.
在存在自旋-轨道耦合的情况下，电子对杂质的散射取决于电子自旋-轨道散射的自旋角动量和轨道角动量。虽然一些输运性质受到自旋轨道散射的影响，但直接获得这种效应的实验技术是有限的。在这里，我们证明了自旋轨道散射的特征在光谱成像扫描隧道显微镜成像的准粒子干涉（QPI）中表现出来。采用t矩阵形式对极性半导体BiTeI的实验数据进行了较好的数值模拟，其中不仅包括通常采用的标量散射，还包括比标量散射更强的自旋轨道散射。为了加速模拟，我们扩展了动量无关散射的标准有效QPI计算方法，使其适用于自旋轨道散射。我们进一步确定了一个选择规则，使自旋轨道散射在QPI模式中可见。这些结果表明，自旋轨道散射对QPI模式有重要影响，从而表明QPI测量可用于检测自旋轨道散射。
In the presence of spin-orbit coupling, electron scattering off impurities depends on both spin and orbital angular momentum of electrons-spin-orbit scattering. Although some transport properties are subject to spin-orbit scattering, experimental techniques directly accessible to this effect are limited. Here we show that a signature of spin-orbit scattering manifests itself in quasiparticle interference (QPI) imaged by spectroscopic-imaging scanning tunneling microscopy. The experimental data of a polar semiconductor BiTeI are well reproduced by numerical simulations with the T-matrix formalism that include not only scalar scattering normally adopted but also spin-orbit scattering stronger than scalar scattering. To accelerate the simulations, we extend the standard efficient method of QPI calculation for momentum-independent scattering to be applicable even for spin-orbit scattering. We further identify a selection rule that makes spin-orbit scattering visible in the QPI pattern. These results demonstrate that spin-orbit scattering can exert predominant influence on QPI patterns and thus suggest that QPI measurement is available to detect spin-orbit scattering.