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arXiv · 2008.00134

Topological charge pumping in excitonic insulators

Zhiyuan Sun·Andrew J. Millis
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Abstract

We show that in excitonic insulators with $s$-wave electron-hole pairing, an applied electric field (either pulsed or static) can induce a $p$-wave component to the order parameter, and further drive it to rotate in the $s+ip$ plane, realizing a Thouless charge pump. In one dimension, each cycle of rotation pumps exactly two electrons across the sample. Higher dimensional systems can be viewed as a stack of one dimensional chains in momentum space in which each chain crossing the fermi surface contributes a channel of charge pumping. Physics beyond the adiabatic limit, including in particular dissipative effects is discussed.

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Zhiyuan Sun, Andrew J. Millis. 2020-08-01. Topological charge pumping in excitonic insulators. https://doi.org/10.1103/physrevlett.126.027601

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