Title: Interactions of solitons and solitary waves with a PT-symmetric defect in nonlinear Kelin-Gordon models
Abstract: In this talk, we describe the interaction of solitons and solitary waves in the nonlinear Klein-Gordon (NKG) equations with a spatially localised parity-time-symmetric perturbation with a balanced gain and loss.
We will demonstrate that when a kink passes the defect, it almost restores its initial momentum and energy.
The only effect of the interaction with the defect is a phase shift of the kink. For the breather, the scattering outcomes are particularly intriguing; it can either split into a kink-antikink pair or lose a part of its energy.
Additionally, we found that when the kink interacts with the defect from the gain side, multiple pairs of the kink–antikink are formed from small-amplitude waves (phonons) in the final states, depending on the initial velocity of the kink and parameter of the perturbation. Some features of these interactions are analytically demonstrated using the collective variable method.