Stability limits for arrays of kinks in two-component nonlinear systems

Interaction between separated solitons in two-component models may give rise to competing repulsion and attraction forces with different spatial scales, as each component produces its own scale and its own sign of the interaction. We demonstrate, in terms of the known generalized Ginzburg-Landau equation for the order parameter u with an additional term ∼u*, that this effect gives rise to a minimum spacing at which periodic arrays of the Bloch-wall (BW) kinks are stable. This minimum spacing diverges as the control parameters approaches a critical value at which the BW merges with the Néel-wall kink and loses its stability, which may be naturally interpreted as a collapse of the generalized Eckhaus stability band at the critical point.