arXiv:quant-ph/0305125 · Physical Review A
Cooperative fluorescence effects for dipole-dipole interacting systems with experimentally relevant level configurations
Volker Hannstein, Gerhard C. Hegerfeldt
Abstract
The mutual dipole-dipole interaction of atoms in a trap can affect their fluorescence. Extremely large effects were reported for double jumps between different intensity periods in experiments with two and three ${\mathrm{Ba}}^{+}$ ions for distances in the range of about ten wave lengths of the strong transition while no effects were observed for ${\mathrm{Hg}}^{+}$ at 15 wavelengths. In this theoretical paper we study this question for configurations with three and four levels, which model those of ${\mathrm{Hg}}^{+}$ and ${\mathrm{Ba}}^{+},$ respectively. For two systems in the ${\mathrm{Hg}}^{+}$ configuration we find cooperative effects of up to 30% for distances around one or two wavelengths, about 5% around ten wavelengths, and, for larger distances in agreement with experiments, practically none. This is similar for two V systems. However, for two four-level configurations, which model two ${\mathrm{Ba}}^{+}$ ions, cooperative effects are practically absent, and this latter result is at odds with the experimental findings for ${\mathrm{Ba}}^{+}.$