Soliton interactions and transformations in hard-sphere colloids

Here we investigate collisions of bistable solitons in the model of colloidal media and demonstrate that the solitons can undergo transformations during their interactions. Moreover, we reveal that the interaction of two solitons from different branches is phase-independent and always repulsive, a surprising result in the view of all previous studies. We provide a simple physical explanation of this phenomenon. We show that the interaction between the solitons is effectively incoherent, and each of the solitons ´feels´ the other one as an effective attractive potential. However, a soliton reflection from a narrow, deep, attractive potential wells or defects has been already reported for different systems. It was shown that if the soliton velocity falls below a certain threshold, repulsive interaction between the soliton and an attractive potential can occur.