Pressure effects on the electronic structure, phonons, and superconductivity of noncentrosymmetric <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi mathvariant="normal">ThCoC</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:math>
Gabriel Kuderowicz, P. Wójcik, Bartłomiej Wiendlocha
Abstract
The electronic structure, phonons, electron-phonon coupling, and superconductivity are theoretically studied in the noncentrosymmetric superconductor $\mathrm{Th}\mathrm{Co}{\mathrm{C}}_{2}$ 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 $\ensuremath{\lambda}$ 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 $\ensuremath{\lambda}$ 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 $\mathrm{Th}\mathrm{Co}{\mathrm{C}}_{2}$.