Mercury chalcogenides is a class of materials that exhibit diverse structural phases under pressure, hosting exotic physical properties, including topological phases and chiral phonons. In particular, recent experimental results on HgS reports a new superconducting phase at 21 GPa, whose origin is unknown. In this letter we theoretically investigate the pressure-induced structural phase transition in HgS and the emergence of superconductivity in the rock salt phase. Remarkably, we discover that the rock salt phase hosts a two-gap superconducting phase originating from distinct Fermi surfaces. The unusually high critical temperature of 11 K emerges naturally within this multiband scenario, highlighting the role of interband coupling beyond isotropic approximation. These results place HgS among the few systems where multiband superconductivity is observed.
@article{arxiv.2507.21869,
title = {Multi-Gap superconductivity in HgS under pressure},
author = {Pietro Maria Forcella and Cesare Tresca and Antonio Sanna and Gianni Profeta},
journal= {arXiv preprint arXiv:2507.21869},
year = {2025}
}