New kink-antikink solitons of the pair-transition-coupled nonlinear Schrödinger equations

Abstract

This work presents three new types of coupled periodic waves in a two-component Bose-Einstein condensates (BEC) with pair-transition effects, which all degenerate to distinctive optical shock-wave pairs in the long-wave limit. The newly obtained kink-antikink soliton waveforms exist in two distinct types and are allowable in the repulsive nonlinear interaction case. The analytical nonautonomous periodic wave and kink-antikink solitons for the pair-transition-coupled nonlinear Schrödinger (NLS) equations with varying coefficients of nonlinearity, diffraction, pair-transition effects, gain/loss, and harmonic potential are obtained by similarity transformation. As an important application, the nonlinear tunneling effects of these constructed chirped nonautonomous kink-antikink solitons are discussed when they pass through nonlinear barrier and nonlinear well. The results indicate that the kink-antikink solitons form valleys or form peaks as they pass through nonlinear barriers or nonlinear wells, respectively.