A semiconductor nanowire with strong spin-orbit coupling in proximity to a superconductor is predicted to display Majorana edge states emerging under a properly oriented magnetic field. The experimental investigation of these exotic states requires assessing the one-dimensional (1D) character of the nanowire and understanding the superconducting proximity effect in the presence of a magnetic field. Here, we explore the quasi-ballistic 1D transport regime of an InAs nanowire with Ta contacts. Fine-tuned by means of local gates, the observed plateaus of approximately quantized conductance hide the presence of a localized electron, giving rise to a lurking Coulomb blockade effect and Kondo physics. When Ta becomes superconducting, this local charge causes an unusual, reentrant magnetic field dependence of the supercurrent, which we ascribe to a 0 - p transition. Our results underline the relevant role of unintentional charge localization in the few-channel regime where helical subbands and Majorana quasi-particles are expected to arise.
Titolo: | Charge localization and reentrant superconductivity in a quasi-ballistic InAs nanowire coupled to superconductors | |
Autori: | ||
Data di pubblicazione: | 2019 | |
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Digital Object Identifier (DOI): | http://dx.doi.org/10.1126/sciadv.aav1235 | |
Handle: | http://hdl.handle.net/11384/81808 | |
Appare nelle tipologie: | 1.1 Articolo in rivista |