We present results for a multichannel tunneling model that describes point-contact spectra between a metallic tip and a superconducting heavy-fermion system. We calculate tunneling spectra both in the normal and superconducting state. In point-contact and scanning tunneling spectroscopy many heavy-fermion materials, like CeCoIn5, exhibit an asymmetric differential conductance, dI/dV, combined with a strongly suppressed Andreev reflection signal in the superconducting state. For Andreev reflection to occur a junction has to be in the highly transparent limit. Here we focus on the opposite limit, namely that of low transparency leading to BCS-like dI/dV curves. We discuss the consequences of a multichannel tunneling model for CeCoIn5 assuming itinerant electron bands and localized f electrons.
@article{arxiv.1009.3054,
title = {Tunneling limit of heavy-fermion point contacts},
author = {Mikael Fogelstrom and Matthias J. Graf},
journal= {arXiv preprint arXiv:1009.3054},
year = {2011}
}