Thermal conductivity of superconducting tunnelling junctions

The first measurements are presented of thermal conductivity of superconducting tunneling junctions. Point contact junctions were established between a GaAs (Zn) point and a superconducting Nb base. A dielectric tip was used made of GaAs (Cr). It is concluded that electrons carry the heat across these type of junctions, in the same way they do in a bulk superconductor, and the the acoustical mismatch at the interface is not affected by the superconducting transition of the base metal. (author)