We present transport spectroscopy of sub-gap states in a bottom gated InAs nanowire coupled to a normal lead and a superconducting aluminium lead. The device shows clearly resolved sub-gap states which we can track as the coupling parameters of the system are tuned and as the gap is closed by means of a magnetic field. We systematically extract system parameters by using numerical renormalization group theory fits as a level of the quantum dot is tuned through a quantum phase transition electrostatically and magnetically. We also give an intuitive description of sub-gap excitations.
@article{arxiv.1609.03988,
title = {Tuning Yu-Shiba-Rusinov States in a Quantum Dot},
author = {Anders Jellinggaard and Kasper Grove-Rasmussen and Morten Hannibal Madsen and Jesper Nygård},
journal= {arXiv preprint arXiv:1609.03988},
year = {2016}
}