Quasiclassical theory of vortices in3He-B

We report weak-coupling numerical calculations of the order parameter and the free energy of isolated vortices in superfluid³He in the framework of the quasiclassical theory of superfluid Fermi-liquids. Unlike earlier work with the Ginzburg-Landau theory, our results are not restricted to the vicinity ofT_c. We show that Fermi-liquid effects play an important role at lower temperatures. It appears there is a transition from the double core vortex to an A-phase-core vortex at the vapor pressure just above 0.5T_c.