Anisotropic gap of superconducting CaC6: A first-principles density functional calculation

A. Sanna; G. Profeta; A. Floris; A. Marini; E. K. U. Gross; S. Massidda

doi:10.1103/PhysRevB.75.020511

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Anisotropic gap of superconducting CaC6: A first-principles density functional calculation

A. Sanna, G. Profeta, A. Floris, A. Marini, E. K. U. Gross, S. Massidda

DOI 10.1103/PhysRevB.75.020511 · Physical Review B

T1

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Abstract

We report first-principles calculations of the superconducting properties of CaC6, obtained within the density functional theory of superconductivity. We find a moderately anisotropic gap which is larger on the Fermi surface sheet with interlayer and Ca character compared with isotropic calculations. Our calculated anisotropy improves the agreement with specific heat experiments and is consistent with recent tunneling experiments. In contrast to MgB2, we do not find multigap superconductivity but, instead, a continuous spread of gap values.

Source-reported materials — not catalogue approval

Formula	Reported Tc (K)	Pressure (GPa)	Type
CaC6 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	11.5	Pressure not reported	unknown
YbC6 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	6.5	Pressure not reported	unknown
CaC6 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	9.4	Pressure not reported	unknown