2008/06/30 by D. H. Santamore, Eddy Timmermans · 2 citations
Physics and Astronomy · #Bose–Einstein condensate #Boson #Cold Atom Physics and Bose-Einstein Condensates #Compressibility #Condensed matter physics #Equation of state #Fermi gas #Fermion #Instability #Phase (matter) #Physics #Physics of Superconductivity and Magnetism #Quantum electrodynamics #Quantum mechanics #Quantum, superfluid, helium dynamics #Spin (aerodynamics) #Spinodal #Thermodynamics #cond-mat.stat-mech #physics.atom-ph
paper · pdf · doi:10.1103/physreva.78.013619
published as Phys. Rev. A 78, 013619 (2008) · 16 pages, 6 figures, typo corrected
arxiv created 2008/07/03 · openalex publication_date 2008/07/17 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We develop a diagrammatic perturbation treatment to calculate the zero-temperature equation of state of the dilute gas mixture of a single spin component Bose-Einstein condensate (BEC) and a normal Fermi gas of indistinguishable (single spin) fermion particles. We find that the mean-field description breaks down near the mechanical instability related to the phase separation phenomenon. Our analysis shows that the instability is caused by the competition of the usual short-range and fermion-mediated boson-boson interactions, which result in a boson compressibility that diverges. In the low BEC-density limit, we show that the diagrammatic analysis simplifies, we sum part of the higher-order diagrams, and we discuss the effects of other higher-order contributions.