2011/01/23 by Murányi, F., Bendele, M., Khasanov, R. +4
#FOS: Physical sciences #Superconductivity (cond-mat.supr-con)
paper · doi:10.48550/arxiv.1101.4386
Muon spin rotation (muSR) experiments were performed on the intercalated graphite CaC6 in the normal and superconducting state down to 20 mK. In addition, AC magnetization measurements were carried out resulting in an anisotropic upper critical field Hc2, from which the coherence lengths xiab(0)=36.3(1.5) nm and xic(0)=4.3(7) nm were estimated. The anisotropy parameter gammaH= Hc2ab/Hc2c increases monotonically with decreasing temperature. A single isotropic s-wave description of superconductivity cannot account for this behaviour. From magnetic field dependent muSR experiments the absolute value of the in-plane magnetic penetretion depth lambdaab=78(3) nm was determined. The temperature dependence of the superfluid density rhos(T) is slightly better described by a two-gap than a single-gap model.