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arXiv 1503.01870cond-mat.str-elcond-mat.mes-hallcond-mat.mtrl-sci
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带拓扑在Wannier-Stark阶梯绕数中的直接表现

Direct manifestation of band topology in the winding number of the Wannier-Stark ladder

Woo-Ram Lee, Kwon Park

摘要:

物质的拓扑量子相一直是当代凝聚态物理研究的热点。拓扑物质包括拓扑绝缘体、拓扑超导体和拓扑半金属等,它们的奇异性质一直受到人们的广泛关注。对于拓扑绝缘体来说,通过无间隙螺旋边缘或表面态的无耗散传输应该发挥决定性作用,不幸的是,由于样品边界中不可避免地诱发反向散射,这在实验中被证明很难实现。出于拓扑不变量和Zak相位之间的基本连接,在这里,我们表明,非平凡的二维和三维拓扑绝缘体,其特征在于陈数和$\mathbb{Z}_2$不变量,分别带拓扑,直接表现在绕组数的Wannier-Stark阶梯(WSL)下出现的电场。我们使用Floquet格林函数的形式主义表明,绕组数的WSL是强大的带间干扰,以及非磁性杂质散射。

英文摘要:

Topological quantum phases of matter have been a topic of intense interest in contemporary condensed matter physics. Extensive efforts are devoted to investigate various exotic properties of topological matters including topological insulators, topological superconductors, and topological semimetals. For topological insulators, the dissipationless transport via gapless helical edge or surface states is supposed to play a defining role, which unfortunately has proved difficult to realize in experiments due to inevitable backscattering induced in the sample boundary. Motivated by the fundamental connection between topological invariants and the Zak phase, here, we show that the non-trivial band topologies of both two and three-dimensional topological insulators, characterized by the Chern numbers and the $\mathbb{Z}_2$ invariants, respectively, are directly manifested in the winding numbers of the Wannier-Stark ladder (WSL) emerging under an electric field. We use the Floquet Green's function formalism to show that the winding number of the WSL is robust against interband interference as well as non-magnetic impurity scattering.

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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