Thermal-Conductivity Measurements of the Proximity Effect

Abstract

The thermal conductivities $K_{\mathrm{es}}$ and $K_{\mathrm{en}}$ in the superconducting and normal states have been measured for four InBi films with Mn layers on each side. The slope of $\frac{K_{\mathrm{es}}}{K_{\mathrm{en}}}$ vs $t$ remains finite as $t\to 1$, as expected for gapless systems. The results indicate that there are states near the Fermi level, probably localized near the boundaries, which remain available at all temperatures.