Large Energy Gaps in CaC₆ from Tunneling Spectroscopy: Possible Evidence of Strong-Coupling Superconductivity

Author

Cihan Kurter, Missouri University of Science and TechnologyFollow
Lutfi Ozyuzer
Daniel Mazur
John F. Zasadzinski
Daniel Rosenmann

Abstract

Tunneling in CaC₆ crystals reproducibly reveals superconducting gaps Δ of 2.3±0.2 meV that are ~40% larger than reported earlier. In an isotropic s -wave scenario, that puts CaC₆ into the class of very strongly coupled superconductors, since 2Δ k Tc ~4.6, implying that soft Ca phonons are primarily involved in the superconductivity. This conclusion explains the relatively large Ca isotope effect found recently for CaC₆, but it could also signal a strong anisotropy in the electron-phonon interaction.

Recommended Citation

C. Kurter et al., "Large Energy Gaps in CaC₆ from Tunneling Spectroscopy: Possible Evidence of Strong-Coupling Superconductivity," Physical review B: Condensed matter and materials physics, vol. 76, no. 22, pp. 220502-1 - 220502-4, American Physical Society (APS), Dec 2007.

The definitive version is available at https://doi.org/10.1103/PhysRevB.76.220502

Department(s)

Physics

International Standard Serial Number (ISSN)

1098-0121

Document Type

Article - Journal

Document Version

Final Version

File Type

text

Language(s)

English

Rights

© 2007 American Physical Society (APS), All rights reserved.

Publication Date

01 Dec 2007