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arXiv · 2110.15254

Isospin and momentum polarized orders in bilayer graphene

Zhiyu Dong·Margarita Davydova·Olumakinde Ogunnaike·Leonid Levitov
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Abstract

Electron bands in the untwisted bilayer graphene flatten out in a transverse electric field, offering a promising platform for correlated electron physics. We predict that the spin/valley isospin magnetism, resembling that seen in moir\'{e} bands, coexists with momentum-polarized phases occurring via a ``flocking transition'' in momentum space. This transition results in the electron momentum distribution being spontaneously displaced relative to the $K$ and $K'$ valley centers. These phases feature unusual observables such as persistent currents in the ground state. Momentum-polarized carriers ``sample'' the Berry curvature of the conduction band, resulting in a unique behavior of the anomalous Hall conductivity and other effects that do not occur in previously studied systems.

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Zhiyu Dong, Margarita Davydova, Olumakinde Ogunnaike, Leonid Levitov. 2021-10-28. Isospin and momentum polarized orders in bilayer graphene. https://doi.org/10.1103/physrevb.107.075108

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