A Nonequilibrium Quantum Field Theory Description of the Bose-Einstein Condensate

Abstract

We study the detailed out of equilibrium time evolution of a homogeneous Bose-Einstein condensate.We consider a nonrelativistic quantum theory for a self-interacting complex scalar field, immersed in a thermal bath, as an effective microscopic model for the description of the Bose-Einstein condensate. This approach yields the following main results:(i) the interaction between fluctuations proves to be crucial in the mechanism of instability generation; (ii) there are essentially two regimes in the $k$-space, with a crossover for $k^2/2m\sim 2\lambda |{\varphi }_0{|}^2$, where, in our notation, $\lambda$ is the coupling constant and $|{\varphi }_0{|}^2$ is the condensate density; (iii) a set of coupled equations that determines completely the nonequilibrium dynamics of the condensate density as a function of the temperature and of the total density of the gas.

4 pages, 1 figure, RevTex Final version to appear in the Physical Review Letters

References in corpus (3)

• The transition temperature of the dilute interacting Bose gas
• Bogoliubov dispersion relation and the possibility of superfluidity for weakly-interacting photons in a 2D photon fluid
• Bose-Einstein condensation and superfluidity of a weakly-interacting photon gas in a nonlinear Fabry-Perot cavity

Cited by in corpus (9)

• Finite Temperature Models of Bose-Einstein Condensation
• Transition Temperature for Weakly Interacting Homogeneous Bose Gases
• Asymptotically Improved Convergence of Optimized Perturbation Theory in the Bose-Einstein Condensation Problem
• Nonequilibrium Dynamics of Coupled Quantum Systems
• Equilibration Time Scales in Homogeneous Bose-Einstein Condensate Dynamics
• Isotropisation of flat homogeneous universes with scalar fields
• Nonequilibrium Precursor Model for the Onset of Percolation in a Two-Phase System
• Beyond Gross-Pitaevskii Mean Field Theory
• Bosonic binary mixtures with Josephson-type interactions