Optically induced flat bands in twisted bilayer graphene
- Creators
- Katz, Or
- Refael, Gil
-
Lindner, Netanel H.
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.
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.Attached Files
Published - PhysRevB.102.155123.pdf
Submitted - 1910.13510.pdf
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Additional details
- Alternative title
- Floquet flat-band engineering of twisted bilayer graphene
- Eprint ID
- 106127
- Resolver ID
- CaltechAUTHORS:20201016-153328923
- 639172
- European Research Council (ERC)
- Institute for Quantum Information and Matter (IQIM)
- Gordon and Betty Moore Foundation
- W911NF-16-1-0361
- Army Research Office (ARO)
- DMR-1839271
- NSF
- Simons Foundation
- David and Lucile Packard Foundation
- PHY-1607611
- NSF
- Created
-
2020-10-16Created from EPrint's datestamp field
- Updated
-
2021-11-16Created from EPrint's last_modified field
- Caltech groups
- Institute for Quantum Information and Matter