Superconducting Tunneling Spectroscopy of a Carbon Nanotube Quantum Dot

TL;DR

This paper presents superconducting tunneling spectroscopy of a carbon nanotube quantum dot, revealing detailed electronic states and scattering processes through enhanced spectroscopic features enabled by a superconducting probe.

Contribution

It introduces a three-probe technique with a superconducting tunnel probe to study quantum dot conductance and excited states in detail.

Findings

Enhanced signals of elastic and inelastic co-tunneling observed

Evidence of inelastic scattering processes inside the quantum dot

Mapping of conductance changes related to band structure and excited states

Abstract

We report results on superconducting tunneling spectroscopy of a carbon nanotube quantum dot. Using a three-probe technique that includes a superconducting tunnel probe, we map out changes in conductance due to band structure, excited states, and end-to-end bias. The superconducting probe allows us to observe enhanced spectroscopic features, such as robust signals of both elastic and inelastic co-tunneling. We also see evidence of inelastic scattering processes inside the quantum dot.