There is still significant debate about the symmetry of the order parameter in the heavy-fermion superconductor UPd2Al3, with proposals for cos(k3), cos(2k3), sin(k3),and exp(i\phi) sin(k3). Here we analyze the tunneling spectroscopy of this compound and demonstrate that the experimental results by Jourdan et al are inconsistent with the last two order parameters, which are expected to show zero-bias conductance peaks. We propose a definitive tunneling experiment to distinguish between the first two order parameters.
@article{arxiv.cond-mat/0612402,
title = {Theory of tunneling spectroscopy in UPd2Al3},
author = {David Parker and Peter Thalmeier},
journal= {arXiv preprint arXiv:cond-mat/0612402},
year = {2009}
}