Charge localization and reentrant superconductivity in a quasi-ballistic InAs nanowire coupled to superconductors

[EN] 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 o...

ver descrição completa

Detalhes bibliográficos
Autores: Estrada Saldaña, J.C., Žitko, R., Cleuziou, J.P., Lee, Eduardo J. H., Zannier, V., Ercolani, D., Sorba, L., Aguado, Ramón, De Franceschi, S.
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2019
País:España
Recursos:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/211321
Acesso em linha:http://hdl.handle.net/10261/211321
Access Level:acceso abierto
Palavra-chave:Semiconductor nanowires
Spin-orbit
Superconductors
Descrição
Resumo:[EN] 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.