Ultrasonic Attenuation in UPt3
Published Web Locationhttps://doi.org/10.1103/physrevlett.53.1009
We report measurements of the ultrasonic absorption in UPt3 through the superconducting transition. The attenuation varies as T2 at low temperature and is inconsistent with the identification of UPt3 as a singlet superconductor. Our results can be well explained by assuming that UPt3 is an anisotropic (triplet) superconductor in a polarlike state, where the gap vanishes along a line on the Fermi surface. © 1984 The American Physical Society.