Pressure effects on the electronic structure, phonons, and superconductivity of noncentrosymmetric ThCoC2

TL;DR

This study investigates how applying pressure up to 20 GPa affects the electronic structure, phonons, and superconductivity of ThCoC2, revealing increased electron-phonon coupling and critical temperature with pressure.

Contribution

It provides the first theoretical analysis of pressure effects on ThCoC2's electronic and superconducting properties, highlighting the role of spin-orbit coupling and electron-phonon interactions.

Findings

Electron-phonon coupling constant increases with pressure.

Critical temperature T_c rises from 2.5 K to 4 K under pressure.

Spin-orbit coupling effects are enhanced by pressure.

Abstract

The electronic structure, phonons, electron-phonon coupling, and superconductivity are theoretically studied in noncentrosymmetric superconductor ThCoC$_2$ as a function of pressure, in the pressure range 0 - 20 GPa. We found that the electronic band splitting induced by the spin-orbit coupling is enhanced under pressure. In spite of the overall stiffening of the crystal lattice, the electron-phonon coupling constant $\lambda$ increases with pressure, from 0.583 at 0 GPa to 0.652 at 20 GPa. If the isotropic Eliashberg electron-phonon coupling theory is used to simulate the effect on the critical temperature $T_c$, such an increase in $\lambda$ results in a substantial increase of $T_c$ from 2.5~K at 0 GPa to 4~K at 20 GPa. This shows that examining the effect of pressure offers a chance to resolve the pairing mechanism in ThCoC$_2$.