2001/08/31 by Eric Braaten, H.‐W. Hammer, H. -W. Hammer +1 · 3 citations
Physics and Astronomy · #Atomic and Subatomic Physics Research #Cold Atom Physics and Bose-Einstein Condensates #Quantum, superfluid, helium dynamics #cond-mat #hep-ph #nucl-th
paper · pdf · doi:10.1103/physrevlett.88.040401
published as Phys.Rev.Lett. 88 (2002) 040401 · 8 pages, RevTex, 1 ps figure, uses epsf.tex, minor changes, references added
openalex publication_date 2002/01/01 · arxiv created 2002/02/01 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We study a dilute Bose gas of atoms whose scattering length a is large compared to the range of their interaction. We calculate the energy density E of a homogeneous Bose-Einstein condensate (BEC) to second order in the low-density expansion, expressing it in terms of a and a second parameter Lambda* that determines the low-energy observables in the three-body sector. The second-order correction to E has a small imaginary part that reflects the instability due to three-body recombination. In the case of a trapped BEC with large negative a, we calculate the coefficient of the three-body mean-field term in E in terms of a and Lambda*. It can be very large if there is an Efimov state near threshold.