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arXiv · 1506.08687

Optical Hall conductivity of a Floquet Topological Insulator

Hossein Dehghani·Aditi Mitra
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Abstract

Results are presented for the optical Hall conductivity of a Floquet topological insulator (FTI) for an ideal closed quantum system, as well as an open system in a nonequilibrium steady-state with a reservoir. The steady-state, even for the open system, is strongly dependent on the topological phase of the FTI, with certain phases showing a remarkable near-cancellation from pockets of Berry-curvature of opposite signs, leading to a suppressed low-frequency Hall conductivity, that also shows an anomalous temperature dependence, by increasing as the temperature of the reservoir is increased. Such a behavior is in complete contrast to heating, and arises because of a strong modification of the effective system-reservoir coupling by the laser. The Berry curvature of the Floquet modes is time-dependent, and its frequency components are found to control the main features of the high-frequency Hall conductivity.

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Hossein Dehghani, Aditi Mitra. 2015-10-27. Optical Hall conductivity of a Floquet Topological Insulator. https://doi.org/10.1103/physrevb.92.165111

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