# A model for superconducting sulfur hydrides

## TL;DR

This paper proposes a multi-band BCS model for sulfur hydride superconductors, incorporating strong coupling effects and isotope shifts to better understand their high critical temperatures.

## Contribution

It introduces a novel multi-band BCS model that accounts for strong coupling and isotope effects in sulfur hydride superconductors.

## Key findings

- The model describes properties of H3S superconductors.
- Strong coupling effects significantly influence isotope coefficients.
- The model aligns with experimental observations of high T_c in sulfur hydrides.

## Abstract

Due to the value of the isotope shift in sulfur hydrides, a phonon-mediated pairing scenario of superconductivity is generally accepted for these high-temperature superconductors which is consistent with the Bardeen-Cooper-Schrieffer (BCS) framework. Knowing that a large electronic density of states enhances $T_c$, generalized Fermi surface topologies are used to increase it. A multi-band model within the BCS framework is proposed in this work for the description of sulfur hydride superconductors. This model is used to describe some properties of the $H_3S$ superconductor. Strong coupling effects are taken into account with the effective McMillan approximation and the isotope coefficient is evaluated as function of the coupling parameter as well as other relevant parameters of the model.