Analysis of Strong-Coupling Parameters for Superfluid 3He
arXiv:cond-mat/0606786 · doi:10.1007/s10909-007-9420-z
Abstract
Superfluid $^{3}$He experiments show strong deviation from the weak-coupling limit of the Ginzburg-Landau theory, and this discrepancy grows with increasing pressure. Strong-coupling contributions to the quasiparticle interactions are known to account for this effect and they are manifest in the five $β$-coefficients of the fourth order Ginzburg-Landau free energy terms. The Ginzburg-Landau free energy also has a coefficient $g_{z}$ to include magnetic field coupling to the order parameter. From NMR susceptibility experiments, we find the deviation of $g_{z}$ from its weak-coupling value to be negligible at all pressures. New results for the pressure dependence of four different combinations of $β$-coefficients, $β$_{345}, $β$_{12}, $β$_{245}, and $β$_{5} are calculated and comparison is made with theory.
6 pages, 2 figures, 1 table. Manuscript prepared for QFS2006