On the Theory of LiquidHe3

Abstract

The difficulties raised by the elementary interpretation of the recently observed temperature variation of the nuclear paramagnetic susceptibility of liquid ${\mathrm{He}}^3$ as an ideal antisymmetric fluid type of degeneration phenomenon are discussed. The susceptibility data are then shown to lead to a direct and rigorous evaluation of the entropy of spin disorder and the associated heat capacity. The observed enormous total entropy of liquid ${\mathrm{He}}^3$ at low temperatures is thus explained to be overwhelmingly entropy of spin disorder. The spin heat capacity is about half of the observed total heat capacity at the lowest temperature of observations. It should tend to become the dominant part of the total liquid heat capacity below this temperature. The maximum of the spin heat capacity at low enough temperatures may become observable indirectly through the total heat capacity of the liquid.