2005/02/21 by I. O. Vakarchuk, Vakarchuk, I. O.
Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Cold Atom Physics and Bose-Einstein Condensates #FOS: Physical sciences #Quantum Physics (quant-ph) #Quantum, superfluid, helium dynamics #quant-ph
paper · pdf · doi:10.48550/arxiv.quant-ph/0502127
28 pages
arxiv created 2005/02/21 · openalex publication_date 2005/02/21 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
A new method is proposed for the calculation of full density matrix and thermodynamic functions of a many-boson system. Explicit expressions are obtained in the pair correlations approximation for an arbitrary temperature. The theory is self-consistent in the sence that the calculated properties at low temperatures coincide with that of Bogoliubov theory and in the high-temperature limit lead to the results for classical non-ideal gas in the random phase approximation. The phase transition is also revealed as a concequence of Bose-Einstein condensation deformed by interatomic interactions. All the final formulae are written solely via the liquid structure factor taken as a source information instead of the interatomic potential and, therefore, interconnect only observable quantities. This gives also a possibility to study such a strongly non-ideal system as liquid He-4.