光调控的Shastry-Sutherland格子上电子的体态-边缘态对应

doi:10.7523/j.issn.2095-6134.2019.05.002

摘要/Abstract

摘要： 在Shastry-Sutherland格子上运动的电子具有丰富的性质。利用Floquet 方法证明在上述系统中高频圆偏振光产生包括Dirac fermion，semi-Dirac fermion，quadratic band touch，SO（3）fermion和具有能隙的多种物相。在考虑自旋轨道耦合作用后，发现4种无能隙激发的相之间是拓扑等价的。通过计算纳米带的边缘态，按照体态-边缘态对应原则，发现这4种无能隙激发相在打开能隙之后都变成拓扑绝缘体。此外，还发现semi-Dirac fermion体态的各向异性色散关系和沿不同方向裁剪的纳米带边缘态之间也同样存在体态-边缘态对应。

关键词: Shastry-Sutherland格子, Floquet方法, 拓扑绝缘体, 体态-边缘态对应

Abstract: Electrons on Shastry-Sutherland (SS) lattice have plentiful properties. We use Floquet theory to demonstrate that a high-frequency circularly polarized light exerted on such a system generates phases including Dirac fermion, semi-Dirac fermion, quadratic band touch, SO(3) fermion gapless phases, and a gapped phase. In the presence of the spin-orbit coupling, those four gapless phases are shown to be topologically equivalent because of the opening of a gap. Through calculating the edge states of a nanoribbon, we further verify that those four gapless phases become topological insulators after the opening of gap according to the bulk-edge correspondence. Besides, we also find the bulk-edge correspondence between the bulk anisotropic dispersion of semi-Dirac fermion and its nanoribbon truncated along two different directions.

Key words: Shastry-Sutherland lattice, Floquet method, topological insulator, bulk-edge correspondence

中图分类号:

金玥苏, 苏刚. 光调控的Shastry-Sutherland格子上电子的体态-边缘态对应[J]. 中国科学院大学学报, 2019, 36(5): 581-589.

JIN Yuesu, SU Gang. Bulk-edge correspondence of light manipulated electrons on Shastry-Sutherland lattice[J]. , 2019, 36(5): 581-589.

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