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