We report the fabrication of a van der Waals tunneling device hosting a defect-bound quantum dot coupled to NbSe2. We find that upon application of magnetic field, the device exhibits a zero-bias conductance peak. The peak, which splits at higher fields, is associated with a Kondo effect. At the same time, the junction retains conventional quasiparticle tunneling features at finite bias. Such coexistence of a superconducting gap and a Kondo effect are unusual, and are explained by noting the two-gap nature of the superconducting state of NbSe2, where a magnetic field suppresses the low energy gap associated with the Se band. Our data shows that van der Waals architectures, and defect-bound dots in them, can serve as a novel and effective platform for investigating the interplay of Kondo screening and superconducting pairing in unconventional superconductors.
@article{arxiv.2212.04571,
title = {Kondo Effect in Defect-bound Quantum Dots Coupled to NbSe$_2$},
author = {T. R. Devidas and Tom Dvir and Enrico Rossi and Hadar Steinberg},
journal= {arXiv preprint arXiv:2212.04571},
year = {2023}
}