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arXiv 1705.09720cond-mat.mes-hall
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Bi2Te3超薄薄膜中拓扑表面态的光电子圆二色性和自旋极化

Photoemission Circular Dichroism and Spin Polarization of the Topological Surface States in Ultrathin Bi2Te3 Films

C. -Z. Xu, Y. Liu, R. Yukawa, L. -X. Zhang, I. Matsuda, T. Miller, T. -C. Chiang

摘要:

圆二色性(CD)对电子态的轨道角动量和自旋角动量敏感,是研究拓扑绝缘体非平凡表面态的有力工具,但迄今为止的实验结果还没有得到全面的描述。我们报告了一项研究的Bi2Te3膜的厚度范围从一个五层(二维限制)到十二层(散装限制)在很宽的入射光子能量。数据显示复杂的变化幅度和符号反转,这仍然是很好地描述了理论计算,包括所有三个光电发射机制:偶极跃迁,表面光电发射,和自旋轨道耦合。结果建立了自旋轨道织构和CD之间的非平凡联系。

英文摘要:

Circular dichroism (CD) observed by photoemission, being sensitive to the orbital and spin angular momenta of the electronic states, is a powerful probe of the nontrivial surface states of topological insulators, but the experimental results thus far have eluded a comprehensive description. We report a study of Bi2Te3 films with thicknesses ranging from one quintuple layer (two-dimensional limit) to twelve layers (bulk limit) over a wide range of incident photon energy. The data show complex variations in magnitude and sign reversals, which are nevertheless well described by a theoretical calculation including all three photoemission mechanisms: dipole transition, surface photoemission, and spin-orbit coupling. The results establish the nontrivial connection between the spin-orbit texture and CD.

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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