2004/06/25 by Thomas Gasenzer
Chemistry · Physics and Astronomy · #Adiabatic process #Atomic physics #Bose–Einstein condensate #Cold Atom Physics and Bose-Einstein Condensates #Context (archaeology) #Excited state #Physics #Population #Quantum mechanics #Quantum optics and atomic interactions #Scattering #Spectroscopy and Laser Applications #cond-mat.other
paper · pdf · doi:10.1103/physreva.70.043618
published as Phys. Rev. A 70, 043618 (2004) · 27 pages revtex, 16 figures
arxiv created 2004/06/25 · openalex publication_date 2004/10/20 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
A dynamical many-body theory of single color photoassociation in a Bose-Einstein condensate is presented. The theory describes the time evolution of a condensed atomic ensemble under the influence of an arbitrarily varying near-resonant laser pulse, which strongly modifies the binary scattering properties. In particular, when considering situations with rapid variations and high light intensities the approach described in this article leads, in a consistent way, beyond standard mean-field techniques. This allows one to address the question of limits to the photoassociation rate due to many-body effects which has caused extensive discussions in the recent past. Both the possible loss rate of condensate atoms and the amount of stable ground-state molecules achievable within a certain time are found to be stronger limited than according to mean-field theory. By systematically treating the dynamics of the connected Green's function for pair correlations the resonantly driven population of the excited molecular state as well as scattering into the continuum of noncondensed atomic states are taken into account. A detailed analysis of the low-energy stationary scattering properties of two atoms modified by the near resonant photoassociation laser, in particular of the dressed state spectrum of the relative motion prepares for the analysis of the many-body dynamics. The consequences of the finite lifetime of the resonantly coupled bound state are discussed in the two-body as well as in the many-body context. Extending the two body description to scattering in a tight trap reveals the modifications to the near resonant adiabatic dressed levels caused by the decay of the excited molecular state.