2008/10/03 by Monique Combescot, M. Combescot, David W. Snoke +1 · 33 citations
Physics and Astronomy · #Bose–Einstein condensate #Boson #Cold Atom Physics and Bose-Einstein Condensates #Composite number #Fermion #Identical particles #Materials science #Physics #Quantum #Quantum mechanics #Quantum, superfluid, helium dynamics #Strong Light-Matter Interactions #Superposition principle #Theoretical physics #cond-mat.other
paper · pdf · doi:10.1103/physrevb.78.144303
published in Physical Review B 78(14) (American Physical Society)
arxiv created 2008/10/03 · openalex publication_date 2008/10/27 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
It is known that elementary bosons condense in a unique state, not so much because this state has the lowest free-particle energy but because it costs a macroscopic amount of energy to put the particles into different states which can then interact through quantum particle exchanges. Since individual exchanges between the two fermions of a composite boson are ignored when composite particles are replaced by elementary bosons, it is of importance to reconsider the exchange-energy argument for the stability of the Bose-Einstein condensate in the case of composite bosons. We do this here in the light of the new many-body theory which allows us to take exactly into account all possible exchanges between the fermionic components of the composite bosons. We confirm that the condensate of composite bosons occupies a single state, this state being moreover pure: a coherent superposition of states close in energy is shown to be less favorable for both elementary and composite bosons.