Abstract
In this tutorial we present an introduction to some theoretical methods of quantum field theory applied to the description of a trapped Bose–Einstein condensate. First of all, we give a brief account of the main characteristics of the phenomenon of condensation and present the many-body Hamiltonian of the system. We outline some of the most important approaches used in the characterization of a condensed Bose gas, including the mean-field theory and the Hartree–Fock–Bogoliubov method. Finally we illustrate the use of these techniques addressing some important issues in quantum atom optics. We characterize the quantum state of a Bose–Einstein condensate (BEC) at zero temperature. We also describe a process of Beliaev coupling between quasiparticles using a method that includes terms beyond the usual Bogoliubov approach.
Original language | English |
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Pages (from-to) | R33-R59 |
Journal | Journal of Optics B: Quantum and Semiclassical Optics |
Volume | 6 |
Issue number | 9 |
DOIs | |
Publication status | Published - 2004 |
Keywords
- article are in colour,atom lasers,bec,bose,bose einstein condensation,entanglement,matter waves,nite temperature eld,nonlinear optics,only in the electronic,parametric down conversion,quasiparticle methods,some gures in this,squeezing,theory,theory of quantized elds