We solved the problem of soliton dynamics in the presence of relaxation. We demonstrate that the spontaneous emission of atoms is strongly suppressed due to nonlinearity. The spatial shape of the soliton is well preserved.
We investigate propagation of a slow-light soliton in Λ-type media such as atomic vapours and Bose–Einstein condensates. We show that the group velocity of the soliton monotonically decreases with the intensity of the controlling laser field, which decays exponentially after the laser is switched off. The shock wave of the vanishing controlling field overtakes the slow soliton and stops it, while the optical information is recorded in the medium in the form of spatially localized polarization. In the strongly nonlinear regime we find an explicit exact solution describing the whole process.
We investigate propagation of slow-light solitons in atomic media described by the nonlinear Λ-model. Under a physical assumption, appropriate to the slow light propagation, we reduce the Λ-scheme to a simplified nonlinear model, which is also relevant to 2D dilatonic gravity. Exact solutions describing various regimes of stopping slow-light solitons can then be readily derived.