Sub-gap spectroscopy of thermally excited quasiparticles in a Nb contacted carbon nanotube quantum dot

Abstract

We present electronic transport measurements of a single wall carbon nanotube quantum dot coupled to Nb superconducting contacts. For temperatures comparable to the superconducting gap peculiar transport features are observed inside the Coulomb blockade and superconducting energy gap regions. The observed temperature dependence can be explained in terms of sequential tunneling processes involving thermally excited quasiparticles. In particular, these new channels give rise to two unusual conductance peaks at zero bias in the vicinity of the charge degeneracy point and allow to determine the degeneracy of the ground states involved in transport. The measurements are in good agreement with model calculations.

5 pages, 4 figures

References in corpus (6)

• Quantum supercurrent transistors in carbon nanotubes
• Transport Through Andreev Bound States in a Graphene Quantum Dot
• Bends In Nanotubes Allow Electric Spin Control and Coupling
• Transport Measurement of Andreev Bound States in a Kondo-Correlated Quantum Dot
• Superconductivity-enhanced bias spectroscopy in carbon nanotube quantum dots
• Carbon Nanotube Quantum Dots with Nb Contacts

Cited by in corpus (3)

• Nb/InAs nanowire proximity junctions from Josephson to quantum dot regimes
• Thermally induced subgap features in the cotunneling spectroscopy of a carbon nanotube
• A particle conserving approach to AC-DC driven interacting quantum dots with superconducting leads