Electron transmission between normal and heavy electron metallic phases in a Kondo lattice system

The interface between a heavy electron coherent metallic phase and an incoherent normal metal phase is discussed. The Fermi momentum mismatch between the two phases causes the carriers to scatter at the interface. The interface conductance is a monotonous increasing function of conduction electron density, n_c, and is less than 60% of that of a clean heavy fermion metal at half-filling ($n_c=1$) and can be measured experimentally. Interface experiments can be used as probe of the nature of the homogenous heavy-fermion state and provide important information on the effects of inhomogeneities in heavy-fermion alloys.