Floquet flat-band engineering of twisted bilayer graphene

ORAL

Abstract

Twisted Bilayer Graphene at the magic twist angle features flat energy bands, which lead to superconducitvity and strong correlation physics. These unique properties are typically limited to an extremely narrow range of twist angles around the magic angle. Here we demonstrate that coherent optical irradiation could lead to emergence of flat isolated Floquet-Bloch bands at a wide range of small twist angles. At small twist angles larger than 1°, these bands exhibit non-trivial topology and a non-zero chern number. We show that the effect can potentially be realized with relatively weak optical beams at the visible-infrared range, potentially allowing for realization of optically tuned flat bands.

*N.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-16-61-0361 “Quantum Materials by Design with Electroma-netic Excitation" sponsored by the U.S. Army. This work was performed in part at Aspen Center for Physics, which is supported by National Science Foundation grant PHY-1607611.

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Presenters

  • Or Katz

    • Technion - Israel Institute of Technology

Authors

  • Or Katz

    • Technion - Israel Institute of Technology

  • Gil Refael

    • Caltech
    • Institute for Quantum Information and Matter, California Institute of Technology
    • Institute of Quantum Information and Matter and Department of Physics, California Institute of Technology, Pasadena, California 91125, USA

  • Netanel Lindner

    • Technion - Israel Institute of Technology