BCS theory of p + h - wave superconductivity

– Recently the superconducting gap functions of the skutterudite PrOs4Sb12 have been proposed [K. Maki et al, Europhys. Lett. 68, 720 (2004)]. The superconductivity is spin-triplet and consists of at least 2 distinct phases in a magnetic field, which bears some resemblance to superfluid 3 He. Here we present our analysis of the thermodynamic properties of these two superconducting states within the weak-coupling BCS theory. The superfluid density of the B phase is compared with recent experimental data. Introduction. – Superconductivity in the cubic heavy-fermion (HF) skutterudite PrOs 4 Sb 12 was discovered in 2002 by Bauer et al [1–3], and since that time many experimental and theoretical studies of this compound have been reported. This superconductivity possesses several unusual characteristics: two distinct phases (the A phase and B phase) in a magnetic field, nodal superconductivity with point nodes, and triplet pairing with chiral symmetry breaking [6–8]. As to the phase diagram, it is still very controversial. We show here in Fig. 1 the recent result by Measson et al [9]. We have shown recently that all the magnetothermal conductivity data [4,7] are consistent with p+h-wave superconductivity with