Na₃Bi(100)的真实紧束缚模型中表面对双表面费米弧的影响
Effects of the surface on double surface Fermi arcs in a realistic tight-binding model of Na$_3$Bi (100)
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中文总结 AI 辅助
该研究基于第一性原理构建Na₃Bi(100)的紧束缚模型，探究表面对双表面费米弧的影响，发现表面可重塑费米弧特征但不破坏其类弧物理性质，局域特性比全局连通性更稳定。
中文摘要 AI 辅助
Na₃Bi是一种拓扑狄拉克半金属（TDSM），可支持双表面费米弧（DSFAs），这对其材料分类及在自旋电子器件中的潜在应用具有重要意义。然而，目前尚不清楚表面如何影响真实的Na₃Bi(100)体系。为探究不同表面对DSFAs的影响，我们基于第一性原理构建了两种Na₃Bi(100)终止面的紧束缚模型。在化学计量比终止面上，我们观测到了预期的DSFAs；在非化学计量比结构中，一个终止面上存在DSFAs，另有两个具有DSFAs诸多特性的环。由此可见，自旋动量锁定、与狄拉克点杂化等局域特性比其全局连通性更为稳定，即表面可重塑费米弧特征，却不会破坏其类弧物理性质。
英文摘要
Na$_3$Bi is a topological Dirac semimetal (TDSM) that can support double surface Fermi arcs (DSFAs), which are important for its material classification and their potential use in spintronic devices. However, it is unclear how the surfaces affect realistic Na$_3$Bi (100) systems. To investigate the effects of diverse surfaces on DSFAs, we consider first principles derived tight-binding models of two Na$_3$Bi (100) terminations. On the stoichiometric termination, we find DSFAs as expected. On the non-stoichiometric structure there are DSFAs on one termination and two loops that retain many of the properties of DSFAs. Thus, the local properties such as spin momentum locking and hybridization with the Dirac points appear to be more robust than their global connectivity. That is, the surface can reshape the arc fingerprint without destroying the arc-like physics.
