Scattering of the asymmetric $\phi^6$ kinks from a $\mathcal{PT}$-symmetric perturbation: Creation of multiple pairs of kink-antikink from phonons

TL;DR

This paper numerically studies how asymmetric $^6$ kinks interact with a localized $ ext{PT}$-symmetric defect, revealing velocity changes and the creation of multiple kink-antikink pairs from phonons depending on initial conditions.

Contribution

It introduces a numerical analysis of asymmetric $^6$ kinks interacting with $ ext{PT}$-symmetric defects, showing novel phenomena like pair creation from phonons.

Findings

Kinks from the gain side have decreased final velocity.

Multiple kink-antikink pairs can form from phonons.

Final velocities are unaffected when approaching from the loss side.

Abstract

Interaction of asymmetric $\phi^6$ kinks with a spatially localized $\mathcal{PT}$-symmetric perturbation is investigated numerically. It has been shown that when the kink (antikink) hits the defect from the gain side, a final velocity of the kink decreases (increases), while for the kink and antikink coming from the opposite direction their final velocities remain unchanged. It is also found that when the kink interacts with the defect from the gain side multiple pair of the kink-antikink are formed from small amplitude waves (phonons) in the final states depending on the initial velocity of the initial kink and parameter of the perturbation.