Hybrid s-wave superconductivity in CrB$_2$
Abstract
In a metal with multiple Fermi pockets, the formation of s-wave superconductivity can be conventional due to electron-phonon coupling or unconventional due to spin fluctuations. We analyze the hexagonal diboride CrB, which is an itinerant antiferromagnet at ambient conditions and turns superconducting upon increasing pressure. While the high pressure behavior of T suggests conventional s-wave pairing, we find that spin fluctuations promoting unconventional s-wave pairing become important in the vicinity of the antiferromagnetic dome. As the symmetry class of the s-wave state is independent of its underlying mechanism, we argue that CrB is a realization of a hybrid s-wave superconductor where unconventional and conventional s-wave mechanisms team up to form a joint superconducting dome.
Cite
@article{arxiv.2211.01054,
title = {Hybrid s-wave superconductivity in CrB$_2$},
author = {Sananda Biswas and Andreas Kreisel and Adrian Valadkhani and Matteo Dürrnagel and Tilman Schwemmer and Ronny Thomale and Roser Valentí and Igor I. Mazin},
journal= {arXiv preprint arXiv:2211.01054},
year = {2023}
}