Electronic structure and superconductivity of BiS2-based compounds LaO1-xFxBiS2

TL;DR

This study uses density-functional perturbation theory to analyze the electronic structure, phonon spectra, and superconductivity of BiS2-based compounds, confirming their conventional electron-phonon superconducting nature with results matching experiments.

Contribution

It provides a detailed first-principles investigation of the superconducting mechanism in BiS2-based compounds, specifically LaO1-xFxBiS2, highlighting the role of electron-phonon coupling.

Findings

Electron-phonon coupling constant lambda = 0.8

Predicted Tc = 9.1 K matches experimental data

Confirmed conventional electron-phonon superconductivity

Abstract

Using the density-functional perturbation theory with structural optimization, we investigate the electronic structure, phonon spectra, and superconductivity of BiS2-based layered compounds LaO1-xFxBiS2. For LaO0.5F0.5BiS2, the calculated electron-phonon coupling constant is equal to lambda = 0.8, and obtained Tc = 9.1 K is very close to its experimental value, indicating that it is a conventional electron-phonon superconductor.