Zero sound and the melting curve of 3He

Abstract

We have analyzed data from existing accurate pressure and molar volume measurements of 3He along the melting curve to determine explicit entropy contributions of the liquid and solid phases. Below 300 mK there is a significant discrepancy between the melting curve data of Grilly 1 and Halperin, et al . 2 The resolution of this problem is the subject of this paper. We find that zero sound makes an important contribution to the liquid entropy and that the superfluid 3He A-transition temperature must be shifted upward.