Erasing odd-parity states in a semiconductor quantum dot coupled to a superconductor

ORAL

Abstract

Andreev bound states (ABS) exhibit many similarities to Majorana bound states (MBS). It would be of interest to study ABS in the system where MBS may emerge. The knowledge of ABS in a single dot is also crucial to understand more complicated systems, such as an artificial NbTiN /InSb dot chain that emulates a 1D Kitaev model. Here we study the erasing of odd-parity ABS in a quantum dot with gate-tunable superconducting coupling. The dot is defined in an InSb nanowire/NbTiN superconductor hybrid system. Fine gates are used to tune the coupling, the barrier and the chemical potential. In weak coupling regime, a parity-changing pattern of ABS is observed inside the Coulomb diamonds. In strong coupling regime, the ABS pattern opens a gap and the odd-parity regime is ‘erased’ from the pattern. We study this transition with different source-drain bias, map the phase boundary between even/odd states in magnetic fields and compare it to a finite-size Majorana nanowire.

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Presenters

  • Po Zhang

    • Department of Physics and Astronomy, University of Pittsburgh
    • University of Pittsburgh

Authors

  • Po Zhang

    • Department of Physics and Astronomy, University of Pittsburgh
    • University of Pittsburgh

  • Hao Wu

    • Department of Physics and Astronomy, University of Pittsburgh
    • University of Pittsburgh
    • Physics, Univ of Pittsburgh

  • Zhaoen Su

    • Department of Physics and Astronomy, University of Pittsburgh

  • Rok Zitko

    • Department of Theoretical Physics, Jozef Stefan Institute

  • Eduardo Lee

    • Department of Condensed Matter Physics, Universidad Autonoma de Madrid

  • Diana Car

    • Applied Physics, Eindhoven University of Technology
    • Eindhoven University of Technology
    • TU Eindhoven

  • Sébastien Plissard

    • LAAS CNRS
    • LAAS Toulouse

  • Moira Hocevar

    • Institut NEEL CNRS
    • Institut Néel CNRS

  • Sasa Gazibegovic

    • Applied Physics, Eindhoven University of Technology
    • Eindhoven University of Technology
    • Applied Physics, Eindhoven Univ. of Technology
    • Department of Applied Physics, Eindhoven University of Technology
    • TU Eindhoven
    • Eindhoven University of Technology, Department of Applied Physics

  • Roy Op het Veld

    • Applied Physics, Eindhoven University of Technology
    • Eindhoven University of Technology
    • Applied Physics, Eindhoven Univ. of Technology

  • Ghada Badawy

    • Applied Physics, Eindhoven University of Technology
    • Eindhoven University of Technology
    • Applied Physics, Eindhoven Univ. of Technology

  • Erik P. A. M. Bakkers

    • Applied Physics, Eindhoven University of Technology
    • Eindhoven University of Technology
    • Applied Physics, Eindhoven Univ. of Technology
    • Department of Applied Physics, Eindhoven University of Technology
    • TU Eindhoven
    • Eindhoven University of Technology, Department of Applied Physics
    • Physics, TU Eindhoven

  • Sergey M Frolov

    • University of Pittsburgh
    • Department of Physics and Astronomy, University of Pittsburgh
    • Physics, Univ of Pittsburgh