Collision Dynamics of Topologically Pumped Solitons

Abstract

Soliton pumping enables controlled transport of localized wave packets through the interplay between nonlinearity and band topology. Interactions between such wave packets provide an additional means to manipulate their localization and subsequent motion. Here, we investigate collisions of solitons in a driven bichromatic lattice, where solitons associated with bands of opposite Chern numbers are pumped toward one another. For intracomponent collisions, the soliton that dominates the collision survives as a localized outgoing wave packet, while the weaker one can lose its distinct localized identity. For intercomponent collisions, attractive interaction produces spatial locking, whereas repulsive interaction induces redistribution toward the lowest band and reverses the motion of the initially excited-band wave packet. Remarkably, for collisions between vector solitons with comparable initial intensities, the difference between their internal relative phases controls the collision outcome, favoring capture for in-phase preparation and re-separation for out-of-phase preparation. These results connect nonlinear scattering with subsequent topological pumping and identify initial intensity, intercomponent interaction, and relative phase as control parameters for manipulating localized transport within the same pumping protocol.