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arXiv · 1708.06116

Chiral response of twisted bilayer graphene

T. Stauber·T. Low·G. Gómez-Santos
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Abstract

We present an effective (minimal) theory for chiral two-dimensional materials. These materials possess an electro-magnetic coupling without exhibiting a topological gap. As an example, we study the response of doped twisted bilayers, unveiling unusual phenomena in the zero frequency limit. An in-plane magnetic field induces a huge paramagnetic response at the neutrality point and, upon doping, also gives rise to a substantial longitudinal Hall response. The system also accommodates nontrivial longitudinal plasmonic modes which are associated with a longitudinal magnetic moment, thus endowing them with a chiral character. Finally, we note that the optical activity can be considerably enhanced upon doping.

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T. Stauber, T. Low, G. Gómez-Santos. 2017-08-21. Chiral response of twisted bilayer graphene. https://doi.org/10.1103/physrevlett.120.046801

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