Superfluid density and viscosity of ³He-A and B

Abstract

The authors have used a torsion pendulum to measure the superfluid density and viscosity of liquid 3 He at pressures of 18.2, 26.0 and 29.7 bar. It was found that rho s in the A-phase is not reproducible; the range of variation is about a factor of two, and large amplitudes tend to give low rho s , as would be expected for orientation of the l-vector by flow. In the B-phase, rho s is about 20% greater than any value found in the A-phase at the same reduced temperature. The viscosity below about 0.9 T c is almost independent of pressure at a given value of (T/T c ); it is slightly lower in the B-phase than in the A-phase.