Superconductivity and electron self-energy in tungsten-sulfur-hydride monolayer

Abstract

Hydrogen-rich structures have recently gained attention as a candidate for room-temperature superconductors. Hydrogen has high phonon frequencies and can be an ideal component for superconductors if it also exhibits strong electron–phonon coupling. In bulk materials, this has been achieved only under very high pressure. Two-dimensional hydrogen-decorated materials can also be expected to become superconductors. Recently, it was shown that a Janus MoSH monolayer can be synthesized (Lu et al 2017 Nat. Nanotechnol. 12 744–9), and a theoretical investigation of this MoSH monolayer claimed that T c = 28.58 K at atmospheric pressure (Liu et al 2022 Phys. Rev. B 105 245420). In this work, we propose that tungsten sulfur hydride (WSH) is also a superconducting Janus monolayer. The Tc is carefully calculated with very high resolution via the Eliashberg spectral function and the electron self-energy. We find that WSH is a conventional BCS superconductor with T c = 12.2 K at ambient pressure. For practical applications, sensitive dependence on substrate is inferred. We also reported the electron self-energy of WSH, which can be compared directly with future measurements from angle-resolved photoelectron spectroscopy.