The Single-Mode Approximation for Chern Bands

ORAL

Abstract

The single-mode approximation (SMA) provides a tool for studying the collective excitations and the stability of the many-body gap in fractional quantum Hall (FQH) systems. In the SMA, one considers trial excitations in the form of density operators projected to the relevant single-particle bands, which for FQH systems are Landau levels. We extend this analysis by considering projection to more general Chern bands. We find that the structure factor of a Chern band factors into universal/Landau level and non-universal/lattice pieces. This allows analytical study of collective excitation gap in fractional Chern insulator (FCI) states when perturbative expansion of the Chern bands is possible. We discuss connections between the SMA and quantum geometry of single-particle bands.

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Presenters

  • David Bauer

    Physics and Astronomy, University of California, Los Angeles

Authors

  • David Bauer

    Physics and Astronomy, University of California, Los Angeles

  • Fenner Harper

    Physics & Astronomy, University of California, Los Angeles, Physics and Astronomy, University of California, Los Angeles, Univ of California - Los Angeles

  • T.S. Jackson

    Physics and Astronomy, University of California, Los Angeles

  • Rahul Roy

    Physics & Astronomy, University of California, Los Angeles, Department of Physics and Astronomy, Univ of California - Los Angeles, Physics and Astronomy, University of California, Los Angeles, Univ of California - Los Angeles