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arXiv · 2507.21869

Multi-Gap superconductivity in HgS under pressure

Pietro Maria Forcella·Cesare Tresca·Antonio Sanna·Gianni Profeta
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Abstract

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.

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Pietro Maria Forcella, Cesare Tresca, Antonio Sanna, Gianni Profeta. 2025-07-31. Multi-Gap superconductivity in HgS under pressure. https://doi.org/10.1103/sp9k-yjh7

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