Compressible and incompressible phases in lattice fractional quantum Hall systems

ORAL

Abstract

We study lattice fractional quantum Hall (FQH) systems in the presence of local potential traps using the exact diagonalization technique. By implementing an array of local potential traps, we show that the system undergoes a series of phase transitions. As the strength of potential traps is increased, the FQH state turns into a compressible metallic state, and then into a topologically trivial insulator. We present the phase diagram as well as convincing numerical evidences which we use to identify these phases and phase transitions, including the energy spectrum, the fidelity metric, the Chern number, and the entanglement spectrum. In addition, we also compare the topological trivial insulator observed in our systems with Anderson insulators, which are expected in ordinary fractional quantum Hall systems in 2D electron gases in the presence of strong impurities.

*This work is supported by DARPA-QuEST, Microsoft Q, and CNAM.

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Authors

  • Shuo Yang

    • Condensed Matter Theory Center, Department of Physics, University of Maryland, College Park, MD 20742

  • Kai Sun

    • University of Maryland
    • Condensed Matter Theory Center, University of Maryland, College Park
    • Condensed Matter Theory Center, Department of Physics, University of Maryland, College Park
    • Condensed Matter Theory Center, Department of Physics, University of Maryland, College Park, MD 20742
    • University of Maryland, College Park

  • Sankar Das Sarma

    • Department of Physics, University of Maryland
    • Condensed Matter Theory Center, Dept. of Physics, University of Maryland
    • Condensed Matter Theory Center, University of Maryland, College Park
    • Condensed Matter Theory Center, Department of Physics, University of Maryland, College Park
    • University of Maryland, College Park
    • Condensed Matter Theory Center, Department of Physics, University of Maryland, College Park, MD 20742
    • Condensed Matter Theory Center, Department of Physics, University of Maryland, College Park, Maryland 20742, USA
    • CMTC, UMD, College Park