A facile approach to calculating superconducting transition temperatures in the bismuth solid phases

TL;DR

This paper presents an ab initio method to predict superconducting transition temperatures in bismuth phases, achieving close agreement with experimental data and providing insights into their electronic and vibrational properties.

Contribution

It introduces a computational approach combining electronic and vibrational calculations with BCS theory to accurately predict Tc in various bismuth phases, including unconfirmed superconductors.

Findings

Predicted Tc values closely match experimental measurements for Bi-I, Bi-II, Bi-III, and Bi-V.

Predicted Tc for Bi-IV is 4.25 K, suggesting potential superconductivity.

The approach effectively links electronic and vibrational properties to superconductivity in bismuth.

Abstract

All solid phases of bismuth under pressure, but one, have been experimentally found to superconduct. From Bi-I to Bi-V, avoiding Bi-IV, they become superconductors and perhaps Bi-IV may also become superconductive. To investigate the influence of the electronic properties N(E) and the vibrational properties F({\omega}) on their superconductivity we have ab initio calculated them for the corresponding experimental crystalline structures, and using a BCS approach have been able to determine their critical temperatures Tc obtaining results close to experiment: For Bi-I (The Wyckoff Phase) we predicted a transition temperature of less than 1.3 mK and a year later a Tc of 0.5 mK was measured; for Bi-II Tc is 3.9 K measured and 3.6 K calculated; Bi-III has a measured Tc of 7 K and 6.5 K calculated for the structure reported by Chen et al., and for Bi-V Tc ~ 8 K measured and 6.8 K calculated. Bi-IV has not been found to be a superconductor but we have recently predicted a Tc of 4.25 K.