Far-infrared signature of the superconducting gap in intercalated graphite CaC6

Abstract

Terahertz reflectance spectra of the Ca-intercalated graphite CaC6 reveal a superconducting gap below 11K. The gap signature lacks a sharp onset to full reflectivity at 2Delta, but rather shows a distribution of gap values consistent with an anisotropic gap. The experimental data were successfully fitted to the gap distribution obtained from density functional calculations by Sanna et al. (Phys.Rev. B75, 020511, 2007). The temperature dependence of the superconducting gap is characteristic for a BCS type superconductor.

References in corpus (13)

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Cited by in corpus (8)

• Pressure-induced Superconductivity in CaC2
• Role of Coulomb interaction in the superconducting properties of CaC6 and H under pressure
• Optical signature of sub-gap absorption in the superconducting state of Ba(Fe,Co)2As2
• Superconductivity in intercalated group-IV honeycomb structures
• Phononic Self energy effects and superconductivity in CaC${}_6$
• Raman scattering from the CaC6 superconductor in the presence of disorder
• Muon spin rotation study of the magnetic penetration depth in the intercalated graphite superconductor CaC6
• Signatures of superconducting gap inhomogeneities in optical properties