2003/05/31 by Jens O Andersen, J. U. Andersen · 4 citations
Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Physics of Superconductivity and Magnetism #Quantum, superfluid, helium dynamics #cond-mat.other #hep-ph #nucl-th
paper · pdf · doi:10.1103/revmodphys.76.599
published as Rev.Mod.Phys.76:599,2004 · 44 pages, 20 Postscript figures. Revised version. Expanded by 7 pages and 4 figs. Updated section on T_c and updated list of references. Discussion on atomic potentials and effective field theory added. Revised version accepted for publication in Review of Modern physics
arxiv created 2004/02/10 · openalex publication_date 2004/07/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
This article reviews recent advances in the theory of the three-dimensional dilute homogeneous Bose gas at zero and finite temperature. Effective-field-theory methods are used to formulate a systematic perturbative framework that can be used to calculate the properties of a system at T=0. The perturbative expansion of these properties is essentially an expansion in the gas parameter √na3, where a is the s-wave scattering length and n is the number density. In particular, the leading quantum corrections to the ground-state energy density, the condensate depletion, and long-wavelength collective excitations are rederived in an efficient and economical manner. Nonuniversal effects are also discussed. These effects are higher-order corrections that depend on properties of the interatomic potential other than the scattering length, such as the effective range. The article critically examines various approaches to the dilute Bose gas in equilibrium at finite temperature. These include the Bogoliubov approximation, the Popov approximation, the Hartree-Fock-Bogoliubov approximation, the \ensuremathΦ-derivable approach, optimized perturbation theory, and renormalization-group techniques. The article ends with a look at recent calculations of the critical temperature of the dilute Bose gas, which include 1/N techniques, lattice simulations, self-consistent calculations, and variational perturbation theory.