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Resonant Processes and Exciton Propagation in a Frozen Gas

J. S. Frasier·V. Celli
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Abstract

We present numerical simulations of a theory of resonant processes in a frozen gas of excited atoms interacting via dipole-dipole potentials that vary as $r^{-3}$, where $r$ is the interatomic separation. The simulations calculate time-dependent averages of transition amplitudes and transition probabilities for a single atom in a given state interacting resonantly with a uniformly distributed random gas of atoms in a different state. The averages are over spatial configurations of the gas atoms, which are held fixed while the resonant interaction creates a Frenkel exciton that can travel from atom to atom. We check that the simulations reproduce previously known exact results when the exciton is not allowed to propagate [Phys. Rev. A 59, 4358 (1999)]. Further, we develop an approximation for the average transition amplitude that compares well with the numerical results for a wide range of values of the system parameters.

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J. S. Frasier, V. Celli. 2000-09-12. Resonant Processes and Exciton Propagation in a Frozen Gas. https://arxiv.org/abs/cond-mat/0008433

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