Understanding the origin of superconducting dome in electron-doped MoS$_2$ monolayer

TL;DR

This study uses first-principles calculations to explore the superconducting dome in electron-doped MoS$_2$ monolayer, revealing phase stability, transition temperature behavior, and the role of charge density waves and structural transitions.

Contribution

It provides a detailed theoretical explanation for the origin of the superconducting dome in doped MoS$_2$, linking phase transitions and charge density waves to superconductivity.

Findings

Superconducting dome successfully recreated across doping range.

Doping increases $T_c$ until CDWs and structural transitions reduce it.

Dynamically stable phases identified in phase diagram.

Abstract

We investigate the superconducting properties of molybdenum disulphide (MoS$_2$) monolayer across a broad doping range, successfully recreating the so far unresolved superconducting dome. Our first-principles findings reveal several dynamically stable phases across the doping-dependent phase diagram. We observe a doping-induced increase in the superconducting transition temperature $T_c$, followed by a reduction in $T_c$ due to the formation of charge density waves (CDWs), polaronic distortions, and structural transition from the H to the 1T$'$ phase. Our work reconciles various experimental observations of CDWs in MoS$_2$ with its doping-dependent superconducting dome structure, which occurs due to the $1\times 1$ H to $2\times 2$ CDW phase transition.