Dynamics of resonant energy transfer in a cold Rydberg gas
Physikalisches Institut der Universität Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
Revised: 3 March 2006
Published online: 15 June 2006
We investigate excitation transfer and migration processes in a cold gas of rubidium Rydberg atoms. Density-dependent measurements of the resonant population exchange for atoms initially excited into the 32P3/2(|mJ|=3/2) state are compared with a Monte Carlo model for coherent energy transfer. The model is based on simulations of small atom subensembles involving up to ten atoms interacting via coherent pair processes. The role of interatomic mechanical forces due to the resonant dipole-dipole interaction is investigated. Good agreement is found between the experimental data and the predictions of the model, from which we infer that atomic motion has negligible influence on the energy transfer up to Rydberg densities of 108 cm-3, that the system has to be described in terms of many-body dynamics, and that the energy transfer preserves coherence on microsecond timescales.
PACS: 32.80.Pj – Optical cooling of atoms; trapping / 32.80.Rm – Multiphoton ionization and excitation to highly excited states / 34.20.Cf – Interatomic potentials and forces
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2006