Soliton interaction in logarithmically saturable media

An analysis, based on the variational approach, is carried out of the interaction between two fully coherentsolitons as well as two partially coherent soliton stripes in a medium with logarithmic nonlinearity.For the coherent case, it is found that the interaction can be both attractive and repulsive depending onthe relative phase. The different interaction scenarios involve a bound system where the distancebetween the solitons oscillates with various magnitude of the oscillation amplitude, including total coalescence,and another where the solitons separate asymptotically. The effect of partial coherence on thesoliton interaction is also studied by analyzing the interaction between two partially coherent solitonstripes. It is found that the strength as well as the character (attractive/repulsive) of the interactionchanges for decreasing coherence. Thus, the general interaction properties of solitons in logarithmic nonlinearmedia are qualitatively similar to those of solitons in nonlinear Kerr media