KINETIC ENERGY AND HEAT CAPACITY OF LIQUID $^4$He

摘要

A new method is proposed for the description of the thermodynamic properties of liquid helium-4 in a wide temperature range, including $lambda$-transition. The density matrix of interacting Bose-particles is used in the approximation of pair correlations [I. O. Vakarchuk, J. Phys. Stud. {f 8}, 223 (2004)]. We obtained the expressions for the kinetic and potential energy and also for the pair structure factor. All the final formulae are written solely via the liquid structure factor extrapolated to $T=0$ taken as a source information instead of the interatomic potential. We calculated the dependence on temperature for the kinetic and potential energy, pair structure factor, and heat capacity. In the domain of low temperatures $0.