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arXiv 2201.05335cond-mat.mtrl-scicond-mat.supr-con
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范德瓦尔斯化合物AuTe2Br中的临界拓扑与压力诱导超导性

Critical topology and pressure-induced superconductivity in the van der Waals compound AuTe2Br

Erjian Cheng, Xianbiao Shi, Limin Yan, Tianheng Huang, Fengliang Liu, Wenlong Ma, Zeji Wang, Shuang Jia, Jian Sun, Weiwei Zhao, Wenge Yang, Yang Xu, Shiyan Li

AI总结:

本研究通过第一性原理计算发现范德瓦尔斯化合物AuTe2Br处于强弱拓扑绝缘态边界,其临界拓扑在15.4GPa压力下保持稳定,施压后发生结构相变并出现超导性,为弱拓扑绝缘体研究提供了新候选材料。

摘要:

量子自旋霍尔效应和拓扑绝缘体的研究拉开了过去十年拓扑材料研究热潮的序幕。与经过复杂设计的量子阱相比,三维弱拓扑绝缘体为实现量子自旋霍尔效应提供了一条天然途径,原因在于它们与量子自旋霍尔绝缘体堆叠结构之间存在绝热关联,且其范德瓦尔斯型结构的样品易于剥离。尽管具备这些优势,弱拓扑绝缘体的理论预测和实验识别仍然十分匮乏。在此,我们基于第一性原理计算表明,AuTe2Br处于强拓扑绝缘态与弱拓扑绝缘态的边界上。更值得关注的是,AuTe2Br的临界拓扑在施加约15.4 GPa的压力前保持稳定,之后会发生结构相变,伴随电子拓扑的改变以及超导性的出现。我们的研究结果确立了AuTe2Br作为弱拓扑绝缘体新候选材料的地位,它具备实现多种其他物质量子拓扑相的潜力。

英文摘要:

The study on quantum spin Hall effect and topological insulators formed the prologue to the surge of research activities in topological materials in the past decade. Compared to intricately engineered quantum wells, three-dimensional weak topological insulators provide a natural route to the quantum spin Hall effect, due to the adiabatic connection between them and a stack of quantum spin Hall insulators, and the convenience in exfoliation of samples associated with their van der Waals-type structure. Despite these advantages, both theoretical prediction and experimental identification of weak topological insulators remain scarce. Here, based on first-principles calculations, we show that AuTe2Br locates at the boundary between a strong and a weak topological insulating state. More interestingly, the critical topology of AuTe2Br persists up to an applied pressure of ~ 15.4 GPa before a structural phase transition accompanied by a change of electronic topology and the onset of superconductivity. Our results establish AuTe2Br as a new candidate for weak topological insulators with the potential to realize various other topological phases of matter.

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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