Abstract
We examine state mixing in a dense, cold Rydberg gas. Cold Rb atom clouds in an optical dipole trap are excited into Rydberg levels using narrow-bandwidth laser pulses. For , two atoms excited to states can be converted to and product states via a Förster resonance. We find, unexpectedly, that up to 50% of the Rydberg atoms are detected in such product states after only 100 ns of interaction time. The experiment is modeled using many-body quantum simulations. To reproduce the mixing fractions measured near Förster resonances, we use an exact, nonperturbative many-atom Hamiltonian in which product states are treated on an equal basis with the laser-excited Rydberg level. Simplified many-body interaction models based on sums over pairwise atomic potentials cannot reproduce the measured mixing fractions.
- Received 28 August 2008
DOI:https://doi.org/10.1103/PhysRevA.79.043420
©2009 American Physical Society