Spin-Polarized 3He–HeII Mixtures in the Static Fluctuation Approximation

Abstract

We have used the so-called static fluctuation approximation (SFA) to calculate the thermodynamic properties of spin-polarized 3He–HeII mixtures at low temperature, T < 0.025 K. This approximation is based on the replacement of the square of the local-field operator with its mean value. A closed set of nonlinear integral equations is derived for spin-up and spin-down systems. This set is solved numerically by an iteration method for a realistic interhelium potential. The mean internal energy per unit volume, the pressure, the entropy per unit volume, and the specific heat per unit volume increase with increasing temperature. The mean internal energy per unit volume, the pressure increase with increasing spin polarization; while the entropy per unit volume and the specific heat per unit volume are weakly–dependent on spin polarization.