CALCULATION OF POINT-CONTACT SPECTRA OF METALS WITH AN ENERGY-DEPENDENT DENSITY OF STATES

The influence of an energy-dependent electronic density of states (DOS) on the point-contact characteristics is studied within the framework of the standard ballistic point-contact theory. We calculate dV/dI vs. V characteristics numerically for the rase of an electronic DOS with a maximum near the Fermi-energy, as it is assumed to exist in heavy-fermion systems. Our calculations yield features as maxima and an asymmetry with respect to zero bias, which are indeed typical for heavy-fermion systems. In the case of dominating elastic scattering, as it is present in alloys, we find that dV/dI characteristics show an apporoximate image of the electronic DOS, 1. e. a <<negative>> of the DOS image of a dV/dI tunneling characteristic.