Inductive Skin Depth Measurements in the Heavy-Electron Superconductor UPt ₃

Abstract

We report radio frequency, r.f., skin depth, δi, measurements in the anisotropic superconductor UPt3. For the r.f. field h||c-axis δi has a weaker low-temperature dependence than the T2 behavior of the d.c. penetration depth reported by Gross et al. A similar temperature dependence is obtained for two other geometries h||a-axis, j||b-axis and h||a-axis, j||c-axis. In addition we report a frequency dependence to the skin depth at temperatures much less than Tc. These results are interpreted as evidence for Bogoliubov quasi-particle–hole contribution to the shielding currents in an anisotropic superconductor.