English

Superconductivity in kagome metals due to soft loop-current fluctuations

Superconductivity 2026-05-22 v2 Strongly Correlated Electrons

Abstract

We demonstrate that soft fluctuations of translation symmetry-breaking loop currents provide a mechanism for unconventional superconductivity in kagome metals that naturally addresses the multiple superconducting phases observed under pressure. Focusing on the rich multi-orbital character of these systems, we show that loop currents involving both vanadium and antimony orbitals generate low-energy collective modes that couple efficiently to electrons near the Fermi surface and mediate attractive interactions in two distinct unconventional pairing channels. While loop-current fluctuations confined to vanadium orbitals favor chiral d+idd+id superconductivity, which spontaneously breaks time-reversal symmetry, the inclusion of antimony orbitals stabilizes an s±s^{\pm} state that is robust against disorder. We argue that these two states are realized experimentally as pressure increases and the antimony-dominated Fermi surface sheet undergoes a Lifshitz transition.

Keywords

Cite

@article{arxiv.2507.16892,
  title  = {Superconductivity in kagome metals due to soft loop-current fluctuations},
  author = {Daniel J. Schultz and Grgur Palle and Asimpunya Mitra and Yong Baek Kim and Rafael M. Fernandes and Jörg Schmalian},
  journal= {arXiv preprint arXiv:2507.16892},
  year   = {2026}
}

Comments

13 + 16 pages; 6+10 figures

R2 v1 2026-07-01T04:14:00.766Z