Optical investigations of the electrodynamics of UPd2Al3

Abstract

We have investigated the electrodynamic response of UPd2Al3. At low temperatures, we observe the formation of a low-frequency narrow resonance, which indicates the development of the many-body coherent state. We do not find any evidence of a gap absorption associated to a spin density wave state below the antiferromagnetic phase transition at TN = 14 K, which would develop as a consequence of a Fermi surface instability.