Abstract

The pressure effects on the electron-phonon coupling (EPC) in superconducting $\mathrm{Ca}{\mathrm{C}}_{6}$ have been extensively studied using first-principles calculations within the rigid muffin-tin approximation. It is found that pairing electrons are mainly attributed to the Ca $3d$ electrons mediated by Ca low-lying, in-plane phonon vibrations. An increase in mean square of the EPC matrix element $⟨{I}^{2}⟩$ and a decrease in Ca low-lying phonon frequency with increasing pressure are mainly responsible for the experimental observation of enhanced superconducting transition temperature. Furthermore, Mulliken population analysis suggests that the pressure-induced charge transfers from Ca to the graphite layers might mainly contribute to the softening behavior of Ca in-plane phonons.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.