Collisional decoherence in the presence of ultrafast optical pulses - art.no. 053405

An expression for the van der Waals interaction between an active atom and a perturber atom is derived using an irreducible tensor representation. Thi s interaction leads to magnetic state decoherence in an ensemble of active atoms. The magnetic state decoherence can be suppressed by the application of ultrafast optical pulses. It is shown that the depolarization cross sect ion can be suppressed by as much as 40% with only four optical pulses durin g a single collision and that, for a large number of pulses, the cross sect ion is proportional to n(0)(-2/11) where n(0) is the number of pulses at th e Weisskopf radius. This paper generalizes our previous results in which th e collisional interaction was modeled as a square pulse.