Theoretical Study of Pressure-Induced Superconductivity in Palladium Chalcogenides*

The pressure-induced superconductivity observed in palladium chalcogenides is not fully understood. Although insulating at ambient conditions, increasing isotropic pressure in PdSe₂ and PdS₂ leads to metallic phases, followed by structural transitions. These materials eventually become superconductors at higher pressure. In PdSe₂, the critical temperature is directly correlated with the bonding strength of Se-Se dumbbells, suggesting phonon mediated superconductivity[1]. However, the opposite is observed in PdS₂[2]. In order to understand the pairing mechanism in these emerging superconducting materials, we investigate the different transition temperatures using first-principles density functional theory and test the phonon mediated pairing hypothesis by calculating the superconducting dome.
[1] ElGhazali et al., Phys. Rev. B 96, 060509(R) (2017)
[2] ElGhazali et al., Phys. Rev. B 100, 014507 (2019)