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arXiv · 1910.04654

Topological charge pumping by sliding moir\'{e} pattern

Manato Fujimoto·Henri Koschke·Mikito Koshino
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Abstract

We study the adiabatic topological charge pumping driven by interlayer sliding in the moir\'{e} superlattices. We show that, when we slide a single layer of the twisted bilayer system relatively to the other, a moir\'{e} pattern flow and a quantized transport of electrons occurs. When the Fermi energy is in a spectral gap, the number of pumped charges in the interlayer sliding process is quantized to a sliding Chern number, which obeys a Diophantine equation analogous to the quantum Hall effect. We apply the argument to the twisted bilayer graphene, and find that energy gaps above and below the nearly-flat bands has non-zero sliding Chern numbers. When the Fermi energy is in either of those gaps, the slide-driven topological pumping occurs perpendicularly to the sliding direction.

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Manato Fujimoto, Henri Koschke, Mikito Koshino. 2019-10-10. Topological charge pumping by sliding moir\'{e} pattern. https://doi.org/10.1103/physrevb.101.041112

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