Abstract
We present an effective (minimal) theory for chiral two-dimensional materials. These materials possess an electromagnetic 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 that 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 and our general approach would enable systematic exploration of 2D material heterostructures with optical activity.
Original language | English (US) |
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Article number | 046801 |
Journal | Physical review letters |
Volume | 120 |
Issue number | 4 |
DOIs | |
State | Published - Jan 25 2018 |
Bibliographical note
Funding Information:We acknowledge interesting discussions with Luis Brey. This work has been supported by Spain’s MINECO under Grants No. MDM-2014-0377, No. FIS2017-82260-P, No. FIS2015-64886-C5-5-P, and No. FIS2014-57432-P, and by the Comunidad de Madrid under Grant No. S2013/MIT-3007 MAD2D-CM. T. L. acknowledges support by the National Science Foundation, NSF/EFRI Grant No. EFRI-1741660.
Publisher Copyright:
© 2018 American Physical Society.