Quantum-metric-induced quantum Hall conductance inversion and reentrant transition in fractional Chern insulators

ORAL

Abstract

The quantum metric of single-particle wave functions in topological flat bands plays a crucial role in determining the stability of fractional Chern insulating (FCI) states. Here, we unravel that the quantum metric causes the many-body Chern number of the FCI states to deviate sharply from the expected value associated with partial filling of the single-particle topological flat band. Furthermore, the variation of the quantum metric in momentum space induces band dispersion through interactions, affecting the stability of the FCI states. This causes a reentrant transition into the Fermi liquid from the FCI phase as the interaction strength increases.

*The work at LANL is partially supported by the U.S. Department of Energy (DOE) National Nuclear Security Administration under Contract No. 89233218CNA000001 through the Laboratory Directed Research and Development Program and was performed, in part, at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the DOE Office of Science, under user Proposals No. 2018BU0010 and No. 2018BU0083. The work at University of Michigan is partially supported by the Air Force Office of Scientific Research through the Multidisciplinary University Research Initiative, Award No. FA9550-23-1-0334, and the Office of Naval Research Multidisciplinary University Research Initiatives Awards No. N00014- 20-1-2479, No. N00014-21-1-2770, and by the Gordon and Betty Moore Foundation Award No. N031710.

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Publication: Phys. Rev. Research 6, L032063

Presenters

  • Ang-Kun Wu

    • Los Alamos National Laboratory

Authors

  • Ang-Kun Wu

    • Los Alamos National Laboratory

  • Siddhartha Sarkar

    • University of Michigan
    • Max Planck Institute for Physics of Complex Systems

  • Xiaohan Wan

    • University of Michigan

  • Kai Sun

    • University of Michigan

  • Shizeng Lin

    • Los Alamos National Laboratory (LANL)
    • Los Alamos National Lab
    • Los Alamos National Laboratory
    • LANL