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