Edge state spectroscopy in GaAs quantum wires

ORAL

Abstract

We probe the integer quantum Hall edge states in a GaAs/AlGaAs 2D electron gas at low electron temperature Te ≈ 10mK using an adjacent, tunnel coupled quantum wire. The tunnelling current peaks when energy and momentum conservation are fulfilled. A vector magnetic field provides a momentum kick to the tunnelling electrons and allows for spectroscopic imaging of more than the first ten Landau level edge states with nanometer real space resolution and down to magnetic fields around 10 mT where nbulk ≈ 500. Upon increasing the field, these states are compressed towards the sample edge, until eventually they become magnetically depopulated and move back into the bulk. In addition the spectroscopy experiment reveals spin splitting, fermi-level pinning, demonstrates the chiral nature of the current carrying edge states, and allows us to extract the exchange interaction in the quantum Hall regime. Theoretical predictions using both, an analytical model and numerical solutions from a single particle Schrödinger solver for hard wall confined Landau levels show excellent agreement with the experiment over the entire range of magnetic field.

*This work was supported by the Swiss NSF, NCCR QSIT, the Swiss Nanoscience Institute.

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Presenters

  • Taras Patlatiuk

    • Univ of Basel

Authors

  • Taras Patlatiuk

    • Univ of Basel

  • C. Scheller

    • Department of Physics, Univ of Basel
    • Univ of Basel

  • D. Hill

    • Univ of California - Los Angeles

  • Yaroslav Tserkovnyak

    • University of California, Los Angeles
    • Physics, University of California Los Angeles
    • Department of Physics and Astronomy, Univ of California - Los Angeles
    • Physics and Astronomy, University of California, Los Angeles
    • Univ of California - Los Angeles
    • Physics and Astronomy, Univ of California - Los Angeles
    • Physics and Astronomy, University of California Los Angeles
    • Department of Physics and Astronomy, University of California, Los Angeles
    • Physics, Univ of California - Los Angeles
    • Department of Physics and Astronomy, University of California Los Angeles

  • Amir Yacoby

    • Harvard University
    • Department of Physics, Harvard University
    • Physics, Harvard University
    • Physics, Harvard Univ
    • Harvard Univ
    • School of Applied Sciences and Engineering, Harvard University

  • Loren Pfeiffer

    • Electrical Engineering, princeton university
    • Department of Electrical Engineering, Princeton University
    • Princeton University
    • Princeton Univ
    • Electrical Engineering, Princeton Univ
    • EE, Princeton University

  • K West

    • Electrical Engineering, princeton university
    • Department of Electrical Engineering, Princeton University
    • Princeton University
    • Univ of Basel
    • Princeton Univ
    • Electrical Engineering, Princeton Univ
    • EE, Princeton University

  • Dominik Zumbuhl

    • Department of Physics, University of Basel
    • Univ of Basel
    • Department of Physics, Univ of Basel
    • Departement of Physics, University of Basel
    • Physics Department, Univ of Basel