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arXiv 1909.05050cond-mat.mes-hallcond-mat.mtrl-sci
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三维Kane-Mele Pt $_2$ HgSe $_3$中的涌现对偶拓扑

Emergent dual topology in the three-dimensional Kane-Mele Pt$_2$HgSe$_3$

Antimo Marrazzo, Nicola Marzari, Marco Gibertini

摘要:

最近,第一个大间隙凯恩-梅勒量子自旋霍尔绝缘体被预测为单层jacutingaite(Pt $_2$ HgSe $_3$),这是2008年在巴西发现的一种天然可剥离矿物。将量子自旋霍尔单层堆叠成范德华层状晶体通常会导致(0;001)弱拓扑相,这不会保护(001)表面上表面态的存在。出乎意料的是,最近的角分辨光电子能谱实验显示,存在分散在大面积的001表面布里渊区的jacutingaite单晶的表面状态。001-表面态被证明是拓扑保护的镜像陈数$C_M=-2$,与节线由自旋轨道相互作用间隙。在这里,我们将二维凯恩-梅勒模型扩展到散装jacutingaite和揭开微观起源的缺口节线和新兴的晶体拓扑秩序。通过使用最大局域化的Wannier函数,我们确定了一个大的非平凡的第二最近层跳跃项,打破了弱拓扑绝缘体的标准范例。在这个术语的补充下,凯恩-梅勒模型的预测与最近的实验和第一性原理模拟非常一致,提供了一个吸引人的概念框架,也与其他由堆叠蜂窝晶格制成的层状材料相关。

英文摘要:

Recently, the very first large-gap Kane-Mele quantum spin Hall insulator was predicted to be monolayer jacutingaite (Pt$_2$HgSe$_3$), a naturally-occurring exfoliable mineral discovered in Brazil in 2008. The stacking of quantum spin Hall monolayers into a van-der-Waals layered crystal typically leads to a (0;001) weak topological phase, which does not protect the existence of surface states on the (001) surface. Unexpectedly, recent angle-resolved photoemission spectroscopy experiments revealed the presence of surface states dispersing over large areas of the 001-surface Brillouin zone of jacutingaite single crystals. The 001-surface states have been shown to be topologically protected by a mirror Chern number $C_M=-2$, associated with a nodal line gapped by spin-orbit interactions. Here, we extend the two-dimensional Kane-Mele model to bulk jacutingaite and unveil the microscopic origin of the gapped nodal line and the emerging crystalline topological order. By using maximally-localized Wannier functions, we identify a large non-trivial second nearest-layer hopping term that breaks the standard paradigm of weak topological insulators. Complemented by this term, the predictions of the Kane-Mele model are in remarkable agreement with recent experiments and first-principles simulations, providing an appealing conceptual framework also relevant for other layered materials made of stacked honeycomb lattices.

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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