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arXiv · 2002.02611

Current-induced reversal of anomalous Hall conductance in twisted bilayer graphene

Ying Su·Shi-Zeng Lin
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Abstract

It is observed experimentally that the sign of the Hall resistance can be flipped by a dc electric current in the twisted bilayer graphene (TBG) at 3/4 filling of the four-fold degenerate conduction flat bands. The experiment implies a switching of the valley polarization (VP) and topology in TBG. Here we present a theory on the current-induced switching of VP and topology. The presence of current in the bulk causes {the} redistribution of {electron occupation} in bands near the Fermi energy, which then deforms and shifts the band dispersion due to the Coulomb interaction. Above a critical current, the original occupied and empty bands can be swapped resulting in the switching of VP and topology.

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Ying Su, Shi-Zeng Lin. 2020-02-07. Current-induced reversal of anomalous Hall conductance in twisted bilayer graphene. https://doi.org/10.1103/physrevlett.125.226401

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