Nuclear Magnetic Relaxation in the Heavy-Fermion Superconductor UPt₃

Abstract

The nuclear magnetic relaxation rate, 1/ T 1 , of 195 Pt in a normal and superconducting state was measured. In the normal state, 1/ T 1 is proportional to T , indicating the Fermi liquid nature of the system. In the superconducting state, 1/ T 1 has no enhancement just below the transition temperature and varies in proportion to T 3 at low temperatures. These results indicate the existence of an anisotropic superconducting energy gap, which vanishes at lines on the Fermi surface.