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
