Vector periodic solitons for three-coupled nonlinear Schrödinger equations

Abstract

Under investigation in this paper are the three-coupled nonlinear Schrödinger (CNLS) equations, which govern the dynamics of solitonic excitations along three-spine [Formula: see text]-helical protein with inhomogeneous effect. The vector periodic solitons (VPSs) of three-CNLS equations have been obtained by a transformation that transforms the corresponding equations to the integrable mixed three-CNLS equations. The VPSs getting from two-bright-one-dark solitons are different to the ones from two-dark-one-bright solitons. The latter propagates on periodic wave background and the interspine interaction coefficient adjusts the oscillation period. Moreover, the different-type VPSs are reported through manipulating external inhomogeneity potential. And it shows that VPSs can transform into bright–bright–bright solitons in the special conditions. Dynamic behaviors of those solitons are discussed through graphic simulation.