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Optically induced flat bands in twisted bilayer graphene

Katz, Or and Refael, Gil and Lindner, Netanel H. (2020) Optically induced flat bands in twisted bilayer graphene. Physical Review B, 102 (15). Art. No. 155123. ISSN 2469-9950. doi:10.1103/PhysRevB.102.155123. https://resolver.caltech.edu/CaltechAUTHORS:20201016-153328923

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Abstract

Twisted bilayer graphene at the magic twist angle features flat energy bands, which lead to superconductivity and strong correlation physics. These unique properties are typically limited to a narrow range of twist angles around the magic angle with a small allowed tolerance. Here, we report on a mechanism that enables flattening of the band structure using coherent optical illumination, leading to emergence of flat isolated Floquet-Bloch bands. We show that the effect can be realized with relatively weak optical beams at the visible-infrared range (below the material bandwidth) and persist for a wide range of small twist angles, increasing the allowed twist tolerance by an order of magnitude. We discuss the conditions under which these bands exhibit a nonzero Chern number. These optically induced flat bands could potentially host strongly correlated nonequilibrium electronic states of matter.


Item Type:Article
Related URLs:
URLURL TypeDescription
https://doi.org/10.1103/PhysRevB.102.155123DOIArticle
https://journals.aps.org/prb/abstract/10.1103/PhysRevB.102.155123PublisherArticle
https://arxiv.org/abs/1910.13510arXivDiscussion Paper
ORCID:
AuthorORCID
Lindner, Netanel H.0000-0003-1879-3902
Alternate Title:Floquet flat-band engineering of twisted bilayer graphene
Additional Information:© 2020 American Physical Society. Received 19 November 2019; revised 7 September 2020; accepted 14 September 2020; published 16 October 2020. We are grateful to F. von Oppen for helpful comments and to S. Fang for helpful discussions. N.H.L. and O.K. acknowledge financial support from the European Research Council (ERC) under the European Union Horizon 2020 Research and Innovation Programme (Grant Agreement No. 639172). We acknowledge support from the IQIM, an NSF Physics Frontier Center funded by Gordon and Betty Moore Foundation. We are grateful for support from ARO MURI W911NF-16-1-0361 “Quantum Materials by Design with Electromagnetic Excitation” sponsored by the U.S. Army, as well as NSF grant 1839271. G.R. is also grateful for support from the Simons Foundation and the Packard Foundation. This work was performed, in part, at Aspen Center for Physics, which is supported by National Science Foundation Grant No. PHY-1607611.
Group:Institute for Quantum Information and Matter
Funders:
Funding AgencyGrant Number
European Research Council (ERC)639172
Institute for Quantum Information and Matter (IQIM)UNSPECIFIED
Gordon and Betty Moore FoundationUNSPECIFIED
Army Research Office (ARO)W911NF-16-1-0361
NSFDMR-1839271
Simons FoundationUNSPECIFIED
David and Lucile Packard FoundationUNSPECIFIED
NSFPHY-1607611
Issue or Number:15
DOI:10.1103/PhysRevB.102.155123
Record Number:CaltechAUTHORS:20201016-153328923
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20201016-153328923
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:106127
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:16 Oct 2020 22:51
Last Modified:16 Nov 2021 18:50

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