Two-gap superconductivity in a Janus MoSeLi monolayer

Abstract: Two-dimensional (2D) lithium-decorated materials have emerged as a significant area of study since the prediction of superconductivity in lithium-decorated graphene at temperatures around 8.1 K, with experimental evidence observed at Tc = 5.9 K. Following earlier studies, this paper focuses on the hexagonal Janus MoSeLi monolayer as a promising candidate for Li-decorated 2D materials. Our research reveals that lithium substitution on a selenium layer of MoSe2 can produce a hexagonal Janus MoSeLi monolayer, which exhibits metallic behavior with potential phonon-mediated superconductivity with a critical temperature Tc of 4.5 K. Additionally, by solving the anisotropic gap equations derived from Migdal-Eliashberg theory, we found that the Janus MoSeLi monolayer exhibits two-gap superconductivity. This finding underscores the potential of hexagonal Janus MoSeLi as a significant Li-decorated 2D material for exploring two-dimensional superconductivity and sets the stage for further investigations into new families of Janus transition-metal chalcogenides.