Kondo effect in defect-bound quantum dots coupled to <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>NbSe</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:math>

Abstract

We report the fabrication of a van der Waals tunneling device hosting a defect-bound quantum dot coupled to ${\mathrm{NbSe}}_{2}$. We find that upon application of a 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 ${\mathrm{NbSe}}_{2}$, 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 an effective platform for investigating the interplay of Kondo screening and superconducting pairing in unconventional superconductors.

Locations

• Physical review. B./Physical review. B - View
• arXiv (Cornell University) - View - PDF