Superfluid 3He 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.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Materials Science(all)
- Condensed Matter Physics