On the thermodynamics of quantum liquids
Abstract
The thermodynamic characteristics of liquid ^{4}He and ^{3}He are determined in the temperature range where effects of the particle statistics can be neglected. Experimental data are used to determine the kinetic energies K_{4}^{0}(n) and K_{3}^{0}(n) of liquid ^{4}He and ^{3}He as functions of density n at T = 0 to an accuracy corresponding to small exchange effects. The potential energies V_{4}^{0}(n) and V_{3}^{0}(n) are indistinguishable to high accuracy and depend linearly on n. The kinetic energies K are inversely proportional to the atomic mass M, so that K_{4}^{0}(n)≅(3/4)K_{3}^{0}(n). A diffusion model of quantum nondegenerate liquids is proposed for liquid ^{4}He. A detailed comparison of theory and experiments reveals the existence of quantum scaling. With a suitable temperature scale, it is possible to obtain reduced thermodynamic characteristics of the quantum nondegenerate liquids that depend weakly on the density of the medium and the particle statistics.
 Publication:

Low Temperature Physics
 Pub Date:
 June 2014
 DOI:
 10.1063/1.4881196
 Bibcode:
 2014LTP....40..475L