Non local inelastic lifetime in micro-ohm tunneling junctions

By quenched condensation onto amorphous Sb ultrathin Cu films were prepared in the thickness range of a few atomic layers. They exhibit very short inelastic lifetimes. We investigated, whether their inelastic electronic lifetime is affected by coupling them to thick Cu films with much longer inelastic lifetimes. Our measurements show, that for sufficiently strong electronic coupling the inelastic lifetime of the ultra-thin Cu film is enhanced and finally becomes comparable to the inelastic lifetime of the thick Cu film. We also measured the Coulomb anomaly in the temperature dependence of the resistance. Our films confirm previous results, that the dynamical Coulomb interaction seems not to be long ranged, as expected.