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arXiv · 1804.09676

Hybridization of sub-gap states in one-dimensional superconductor/semiconductor Coulomb islands

E. C. T. O'Farrell·A. C. C. Drachmann·M. Hell·A. Fornieri·A. M. Whiticar·E. B. Hansen·S. Gronin·G. C. Gardener·C. Thomas·M. J. Manfra·K. Flensberg·C. M. Marcus·F. Nichele
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Abstract

We present measurements of one-dimensional superconductor-semiconductor Coulomb islands, fabricated by gate confinement of a two-dimensional InAs heterostructure with an epitaxial Al layer. When tuned via electrostatic side gates to regimes without sub-gap states, Coulomb blockade reveals Cooper-pair mediated transport. When sub-gap states are present, Coulomb peak positions and heights oscillate in a correlated way with magnetic field and gate voltage, as predicted theoretically, with (anti) crossings in (parallel) transverse magnetic field indicating Rashba-type spin-orbit coupling. Overall results are consistent with a picture of overlapping Majorana zero modes in finite wires.

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E. C. T. O'Farrell, A. C. C. Drachmann, M. Hell, A. Fornieri, A. M. Whiticar, E. B. Hansen, S. Gronin, G. C. Gardener, C. Thomas, M. J. Manfra, K. Flensberg, C. M. Marcus, F. Nichele. 2018-04-25. Hybridization of sub-gap states in one-dimensional superconductor/semiconductor Coulomb islands. https://doi.org/10.1103/physrevlett.121.256803

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