Detection of Majorana non-locality in hybrid dot-nanowire systems II: Experiments

ORAL

Abstract

The spatial non-locality nature of Majorana bound states (MBS) is the key ingredient for their topological protection. While several tunneling experiments have reported Majorana signatures in the form of a zero- bias conductance peak, a demonstration of non-local Majoranas as opposed to local Andreev levels coalescing near zero energy is still lacking. Here we demonstrate that a local transport measurement can be used to quantify the degree of Majorana non-locality associated to a zero-bias peak. This seemingly contradicting result can be achieved by measuring the sensitivity of the zero-energy state to a local perturbation created by a gate-tunable quantum dot located at the end of a nanowire, which simultaneously acts as a tunnel spectroscopic probe. The degree of sensitivity is then connected to the Majorana wavefunction overlap using theoretical tools [1]. Using this approach, we observed zero-bias peaks from low to high degree of wavefunction non-locality [2]. The first part of this talk (I) will focus on theory aspects while the second part (II) will present the experimental data.
[1] E. Prada, R. Aguado and P. San-Jose, Phys. Rev. B 96, 085418 (2017)
[2] M. T. Deng, S. Vaitiekenas, E. Prada, P. San-Jose, J. Nygard,1 P. Krogstrup, R. Aguado and C. M. Marcus, in preparation.

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Presenters

  • Mingtang Deng

    • Center for quantum devices, Niels Bohr Institute
    • Lund University, Department of solid state physics

Authors

  • Mingtang Deng

    • Center for quantum devices, Niels Bohr Institute
    • Lund University, Department of solid state physics

  • Ramon Aguado

    • Materials Science Factory, ICMM, CSIC
    • Materials Science Factory, ICMM, CSIC - Madrid
    • Materials Science Factory, Instituto de Ciencia de Materiales de Madrid (ICMM), CSIC

  • Saulius Vaitiekenas

    • Center for quantum devices, Niels Bohr Institute
    • Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen

  • Elsa Prada

    • IFIMAC and Universidad Autonoma de Madrid, UAM
    • Universidad Autonoma de Madrid

  • Pablo San-Jose

    • Materials Science Factory, ICMM, CSIC
    • Materials Science Factory, ICMM, CSIC - Madrid
    • Materials Science Factory, Instituto de Ciencia de Materiales de Madrid (ICMM), CSIC

  • Jesper Nygard

    • Center for quantum devices, Niels Bohr Institute
    • Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute
    • Center for Quantum Devices and Station-Q Copenhagen, Niels Bohr Institute, University of Copenhagen
    • Center for Quantum Devices, Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen
    • Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen
    • Center of Quantum Devices and Nano-Science Center, Niels Bohr Institute, University of Copenhagen

  • Charles Marcus

    • Center for Quantum Devices and Station Q, University of Copenhagen
    • Center for quantum devices, Niels Bohr Institute
    • Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute
    • University of Copenhagen