Foa Torres L E F, Perez-Piskunow P M, Balseiro C A, Usaj Gonzalo
Instituto de Física Enrique Gaviola (CONICET) and FaMAF, Universidad Nacional de Córdoba, 5000 Córdoba, Argentina.
Centro Atómico Bariloche and Instituto Balseiro, Comisión Nacional de Energía Atómica, 8400 Bariloche, Argentina and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina.
Phys Rev Lett. 2014 Dec 31;113(26):266801. doi: 10.1103/PhysRevLett.113.266801. Epub 2014 Dec 22.
We report on simulations of the dc conductance and quantum Hall response of a Floquet topological insulator using Floquet scattering theory. Our results reveal that laser-induced edge states lead to quantum Hall plateaus once imperfect matching with the nonilluminated leads is lessened. The magnitude of the Hall plateaus, however, is not directly related to the number and chirality of all the edge states at a given energy, as usual. Instead, the plateaus are dominated by those edge states adding to the time-averaged density of states. Therefore, the dc quantum Hall conductance of a Floquet topological insulator is not directly linked to topological invariants of the full Floquet bands.
我们报告了使用弗洛凯散射理论对弗洛凯拓扑绝缘体的直流电导和量子霍尔响应进行的模拟。我们的结果表明，一旦与未受光照的引线之间的不完美匹配程度降低，激光诱导的边缘态就会导致量子霍尔平台。然而，霍尔平台的大小与给定能量下所有边缘态的数量和手性并不像通常那样直接相关。相反，这些平台由那些增加时间平均态密度的边缘态主导。因此，弗洛凯拓扑绝缘体的直流量子霍尔电导与完整弗洛凯能带的拓扑不变量没有直接联系。
