Interactions and superconductivity in heavily doped MoS2

TL;DR

This paper investigates the microscopic mechanisms behind the recently observed superconductivity in heavily doped MoS2, highlighting the roles of valley structure, Coulomb screening, and electron-phonon interactions in forming a novel phase with sign-changing order parameters.

Contribution

It introduces a detailed analysis of how valley-dependent interactions and screening effects enable a unique superconducting phase in doped MoS2, resembling high-temperature superconductors.

Findings

Superconductivity in doped MoS2 involves sign-changing order parameters across valleys.

Valley structure and Coulomb screening are crucial for the emergence of this phase.

Weak electron-phonon interactions contribute to the unconventional pairing mechanism.

Abstract

We analyze the microscopic origin and the physical properties of the superconducting phase recently observed in MoS$_2$. We show how the combination of the valley structure of the conduction band, the density dependence of the screening of the long range Coulomb interactions, the short range electronic repulsion, and the relative weakness of the electron-phonon interactions, makes possible the existence of a phase where the superconducting order parameter has opposite signs in different valleys, resembling the superconductivity found in the pnictides and cuprates.