Edge State Wave-Functions and Velocities from Tunneling Spectroscopy

ORAL

Abstract

We perform momentum-conserving tunneling spectroscopy using a GaAs cleaved-edge overgrowth quantum wire to investigate adjacent quantum Hall edge states [1]. We use the wire modes with their distinct wave functions to probe each edge state and apply B-fields to modify the wave functions and their overlap. This reveals an intricate and rich tunneling conductance fan structure which is succinctly different for each of the wire modes. We self-consistently solve the Poisson-Schrödinger equations to simulate the spectroscopy, reproducing the striking fans in great detail, thus, confirming the calculations.
Finally, we extend this technique further by applying a finite bias voltage, allowing us to extract the edge state velocities from the slopes of the tunneling spectroscopy in a magnetic field. To obtain the proper velocities, it is important to independently measure the voltage dropped across the tunnel junction, which can differ up to a factor of two from the applied voltage. Overall, this establishes momentum-conserving tunneling spectroscopy as a powerful technique to probe edge states.
[1] T. Patlatiuk and C. P. Scheller et al., PRL 125, 087701, (2020)

*Supported by Swiss NSF, NCCR QSIT, SNI, European Microkelvin Platform (EMP), NSF, EPiQS, MRSEC, FAPESP, CNPq.

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Presenters

  • Taras Patlatiuk

    • University of Basel

Authors

  • Taras Patlatiuk

    • University of Basel

  • Christian Scheller

    • Physics, University of Basel
    • University of Basel

  • Daniel Hill

    • University of California, Los Angeles
    • Johns Hopkins University

  • Yaroslav Tserkovnyak

    • University of California, Los Angeles
    • Physics, UCLA
    • Department of Physics and Astronomy, University of California, Los Angeles

  • Carlos Egues

    • Instituto de Física de São Carlos, Universidade de São Paulo
    • University of Sao Paulo, Sao Carlos
    • Instituto de Física de São Carlos
    • Institute of Physics of São Carlos, University of São Paulo

  • Gilad Barak

    • Harvard University

  • Amir Yacoby

    • Department of Physics, Harvard University
    • Harvard University

  • Loren Pfeiffer

    • Princeton University
    • Princeton Institute for the Science and Technology of Materials (PRISM), Princeton University
    • Department of Electrical Engineering, Princeton University
    • Electrical Engineering, Princeton
    • Electrical Engineering, Princeton University
    • Princeton

  • Ken W. West

    • Princeton University
    • Princeton Institute for the Science and Technology of Materials (PRISM), Princeton University
    • Department of Electrical Engineering, Princeton University
    • Electrical Engineering, Princeton
    • Electrical Engineering, Princeton University
    • Princeton

  • Dominik Zumbuhl

    • University of Basel
    • Physics, University of Basel
    • Department of Physics, University of Basel