Interferometric measurements to test non-Abelian properties of e/4 charges in the fractional quantum Hall state at 5/2

ORAL

Abstract

The excitations of charge e/4 at 5/2 filling factor are proposed to obey non-Abelian statistics. To test this, interferometry at fractional quantum Hall states can be performed that controllably braids edge currents around localized charges. We have conducted these measurements in a large number of interferometers of different sizes, also using multiple designs of high quality 2D electron heterostructures. We observe properties of the interference measurements at 5/2 that are specifically consistent with non-Abelian e/4. In particular, magnetic field sweeps around 5/2 show interference oscillations with frequency spectra that are consistent in detail with non-Abelian e/4 properties. Four frequency spectra peaks are observed corresponding to both e/4 and e/2 charges; importantly a rapid non-Abelian e/4 component is seen that is split due to beating between the two e/4 braiding processes. We review these results and their observation in a range of interferometer dimensions and in different heterostructure designs.

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Authors

  • Robert Willett

    Alcatel-Lucent/Bell Labs

  • Michael Manfra

    Purdue University Dept. of Physics, Purdue University, Department of Physics and Astronomy, and School of Materials Engineering, and School of Electrical and Computer Engineering, Purdue University

  • 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

  • Kirill Shtengel

    Univ of California - Riverside, University of California, Riverside, University of California - Riverside

  • Chetan Nayak

    University of California, Santa Barbara, and Microsoft Q