Fragile topology and flat-band superconductivity in the strong-coupling regime

ORAL

Abstract

Recent theoretical works unveiled that crystalline symmetries can stabilize topologically fragile Bloch bands that challenge our very notion of topology: one can trivialize these bands through the addition of trivial Bloch bands. Here, we show via auxiliary-field Monte Carlo simulations how fragile topology enhances the superfluid weight and hence the superconducting critical temperature. This feature is particularly relevant in flat-band systems where the conventional contribution to the superfluid weight vanishes and might explain the high transition temperature observed in magic-angle twisted bilayer graphene.

*Swiss National Supercomputing Centre, Swiss National Science Foundation, the NCCR QSIT, European Research Council under the Grant Agreement No. 771503, Department of Energy Grant No. DE-SC0016239, the Schmidt Fund for Innovative Research, Simons Investigator Grant No. 404513, the Packard Foundation, the National Science Foundation EAGER Grant No. DMR-1643312, NSF-MRSEC No. DMR-1420541, BSF Israel US foundation No. 2018226, ONR No. N00014-20-1-2303, and the Princeton Global Network Funds.

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Presenters

  • Valerio Peri

    • Department of Physics, ETH Zurich

Authors

  • Valerio Peri

    • Department of Physics, ETH Zurich

  • Zhida Song

    • Department of Physics, Princeton University
    • Princeton University
    • Physics, Princeton University

  • Andrei B Bernevig

    • Department of Physics, Princeton University
    • Princeton University
    • Princeto University, Princeton, USA
    • Physics, Princeton University

  • Sebastian Huber

    • Department of Physics, ETH Zurich
    • Institute for Theoretical Physics, ETH Zurich
    • ETH Zurich
    • Physics, ETH Zurich