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arXiv · 1712.07972

Probing electron-hole components of subgap states in Coulomb blockaded Majorana islands

Esben Bork Hansen·Jeroen Danon·Karsten Flensberg
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Abstract

Recent tunneling spectroscopy experiments in semiconducting nanowires with proximity-induced superconductivity have reported robust zero-bias conductance peaks. Such a feature can be compatible with the existence of topological Majorana bound states (MBSs) and with a trivial Andreev bound state (ABS) near zero energy. Here, we argue that additional information, that can distinguish between the two cases, can be extracted from Coulomb-blockade experiments of Majorana islands. The key is the ratio of peak heights of consecutive conductance peaks give information about the electron and hole components of the lowest-energy subgap state. In the MBS case, this ratio goes to one half for long wires, while for short wires with finite MBS overlap it oscillates a function of Zeeman energy with the same period as the MBS energy splitting. We explain how the additional information might help to distinguish a trivial ABS at zero energy from a true MBS and show case examples.

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Esben Bork Hansen, Jeroen Danon, Karsten Flensberg. 2018-01-16. Probing electron-hole components of subgap states in Coulomb blockaded Majorana islands. https://doi.org/10.1103/physrevb.97.041411

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