Antiferromagnetism and the node structure of the superconducting order parameter of UPd_2Al_3

摘要

The node structure of the superconducting order parameter of the heavy-fermion system UPd_2Al_3 is analyzed within the weak-coupling theory. A pairing interaction induced by the exchange of antiferromagnetic spin excitations is assumed as suggested by recent inelastic neutron scattering experiments and tunneling spectroscopy. The multi-sheeted Fermi surface is taken into account. Based on a model susceptibility for the simple antiferromagnetic structure of UPd_2Al_3, line nodes result at the rim of the magnetic Brillouin zone.