Pressure-induced superconductivity up to 13.1 K in the pyrite phase of palladium diselenide PdS e2

The evolution of electrical transport properties, the electronic band structure, and lattice dynamics of PdSe2 is studied under high pressure. The emergence of superconductivity is reported in the high-pressure pyrite-type phase of PdSe2. In this transition-metal dichalcogenide, the critical temperature of superconductivity rapidly increases with pressure up to 13.1 K. Ab initio electronic band structure calculations indicate the presence of Dirac and nodal-line fermions in the vicinity of the Fermi energy protected by the pyrite structure symmetry, which can lead to interesting superconducting states. Raman spectroscopy shows a direct correlation between critical temperature and bonding strength of Se-Se dumbbells in PdSe2, underlining the crucial role of bonding for tuning the superconductivity.