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

The electronic structure, phonons, electron-phonon coupling, and superconductivity are theoretically studied in the noncentrosymmetric superconductor ThCoC2 as a function of pressure in the pressure range 0 to 20 GPa. We find 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 ?? 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 Tc, such an increase in ?? results in a substantial increase of Tc 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 ThCoC2.

Automated summary

In this study, the electronic structure, phonons, electron-phonon coupling, and superconductivity of the noncentrosymmetric superconductor ThCoC2 were theoretically investigated as a function of pressure. The results showed that pressure can enhance the electronic band splitting induced by spin-orbit coupling and increase the electron-phonon coupling constant Λ despite the overall stiffening of the crystal lattice. Furthermore, simulation results using the isotropic Eliashberg electron-phonon coupling theory revealed that the critical temperature Tc significantly increased with the increase in Λ, offering a chance to resolve the pairing mechanism in ThCoC2.