SURFACE SUPERCONDUCTIVITY AND H-C3 IN UPT3

Ginzburg-Landau (GL) theory is used to study surface superconductivity for UPt3 for various order parameter symmetries (OPS), and H-c3 is fo und for all principal directions of the surface normal (n) over cap an d the field [1]. Assuming specular reflection, and allowing for reorie ntation of the antiferromagnetic symmetry breaking field in the models with E(1g), E(2g), E(1u), or E(2u) symmetry, the experiments of Kelle r et al. [2] with (n) over cap = <(alpha)over cap> can be qualitativel y explained for all OPS except possibly A(1u) + B-1u. The implied GL p arameters then predict qualitatively different and OPS dependent behav ior for (n) over cap = <(alpha)over cap> and (n) over cap = (c) over cap. Study of H-c3 for these surfaces would give strong clues about th e OPS of UPt3.