Anisotropic Composite Fermions and Fractional Quantum Hall Effect

ORAL

Abstract

We study the role of Fermi sea anisotropy on the transport properties of composite Fermions near Landau level filling factor $\nu=1/2$ in two-dimensional hole systems confined to GaAs quantum wells. By applying a parallel magnetic field, we tune the Fermi sea anisotropy and monitor the relative change of the transport scattering time along its principal directions. Interpreted in a simple Drude model, our results suggest that the scattering time is longer along the longitudinal direction of the Fermi sea. Furthermore, we find that the measured energy gap for the fractional quantum Hall state at $\nu=2/3$ decreases when anisotropy becomes significant.

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Authors

  • M A MUEED

    • Princeton University

  • Dobromir Kamburov

    • Princeton University

  • Sukret Hasdemir

    • Princeton University

  • Mansour Shayegan

    • Princeton University
    • Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544

  • Loren Pfeiffer

    • Princeton University
    • Dept. of Electrical Engineering, Princeton University, Princeton, NJ
    • Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544
    • Department of Electrical Engineering, Princeton University
    • Princeton

  • Ken West

    • Princeton University
    • Dept. of Electrical Engineering, Princeton University, Princeton, NJ
    • Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544
    • Princeton

  • Kirk Baldwin

    • Princeton University