Exact solution for spontaneous emission in the presence of N atoms
F.W. Cummings, Ali Dorri · Physical Review A · 1983
$N$ two-level "atoms" are considered in interaction with a single-mode resonant electromagnetic field. The exact solution is given nonrelativistically for all times for the case of spontaneous emission, when only one atom is initially excited. The solution is given for the general case of the $N$ atoms in inequivalent mode positions.