Illuminating "spin-polarized" Bloch wave-function projection from degenerate bands in decomposable centrosymmetric lattices
Illuminating "spin-polarized" Bloch wave-function projection from degenerate bands in decomposable centrosymmetric lattices
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DOI：
10.1103/physrevb.97.125434
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发表时间：
2018-01
影响因子：
3.7
通讯作者：
Pengke Li;I. Appelbaum
中科院分区：
文献类型：
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作者：
Pengke Li;I. Appelbaum
空间反转和时间反转对称性的结合导致具有相反自旋的双简并布洛赫态。许多具有这些对称性的晶格可以通过将非中心对称势（缺乏这种简并性）与其反向副本结合来构造。使用简单的模型，我们揭示了在存在自旋-轨道相互作用和亚晶格耦合的情况下，在反转对称性恢复过程中局部自旋分裂的演变。重要的是，通过对量子力学交换性的分析，我们研究了识别同时空间分离和自旋极化的状态的困难。我们还解释了如何实验探针（如角分辨光电子能谱，或ARPES）的“隐藏的自旋极化”在层状材料中容易受到不相关的自旋分裂本质上引起的破坏反演对称性在表面上。
The combination of space inversion and time reversal symmetries result in doubly-degenerate Bloch states with opposite spin. Many lattices with these symmetries can be constructed by combining a noncentrosymmetric potential (lacking this degeneracy) with its inverted copy. Using simple models, we unravel the evolution of local spin-splitting during this process of inversion symmetry restoration, in the presence of spin-orbit interaction and sublattice coupling. Importantly, through an analysis of quantum mechanical commutativity, we examine the difficulty of identifying states that are simultaneously spatially segregated and spin polarized. We also explain how experimental probes (such as angle-resolved photoemission spectroscopy, or ARPES) of `hidden spin polarization' in layered materials are susceptible to unrelated spin splitting intrinsically induced by broken inversion symmetry at the surface.