Magnetic versus Nonmagnetic Mechanism for Thermal Boundary Conductances at Millikelvin Temperatures

Abstract

It is pointed out that, for the anomalous thermal boundary conductances between metal particles and liquid ³He observed at mK temperatures, randomly distributed spins near the surface and the soft mode of metal particles play a comparable role. This is concluded from the analysis of the recent measurements of boundary conductances by Osheroff and Richardson, where a novel magnetic field dependence has been found for the boundary between silver particles and liquid ³He in the mK region.