Zero energy states clustering in an elemental nanowire coupled to a superconductor

Lauriane C Contamin; Lucas Jarjat; William Legrand; Audrey Cottet; Takis Kontos; Matthieu R Delbecq

doi:10.1038/s41467-022-33960-z

Zero energy states clustering in an elemental nanowire coupled to a superconductor

Nat Commun. 2022 Oct 19;13(1):6188. doi: 10.1038/s41467-022-33960-z.

Authors

Lauriane C Contamin^#¹, Lucas Jarjat^#¹, William Legrand¹, Audrey Cottet¹, Takis Kontos¹, Matthieu R Delbecq²

Affiliations

¹ Laboratoire de Physique de l'École normale supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris Cité, F-75005, Paris, France.
² Laboratoire de Physique de l'École normale supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris Cité, F-75005, Paris, France. matthieu.delbecq@ens.fr.

^# Contributed equally.

Abstract

Nanoelectronic hybrid devices combining superconductors and a one-dimensional nanowire are promising platforms to realize topological superconductivity and its resulting exotic excitations. The bulk of experimental studies in this context are transport measurements where conductance peaks allow to perform a spectroscopy of the low lying electronic states and potentially to identify signatures of the aforementioned excitations. The complexity of the experimental landscape calls for a benchmark in an elemental situation. The present work tackles such a task using an ultra-clean carbon nanotube circuit. Specifically, we show that the combination of magnetic field, weak disorder and superconductivity can lead to states clustering at low energy, as predicted by the random matrix theory predictions. Such a phenomenology is very general and should apply to most platforms trying to realize topological superconductivity in 1D systems, thus calling for alternative probes to reveal it.