Defect solitons supported by nonlocal PT symmetric superlattices

TL;DR

This paper explores the existence and stability of defect solitons in nonlocal PT symmetric superlattices, revealing how defect type and potential parameters influence soliton behavior and stability.

Contribution

It provides the first detailed analysis of defect solitons in nonlocal PT symmetric superlattices, highlighting stability conditions related to defect type and potential phase transition.

Findings

Stable in-phase solitons exist for positive or zero defects in the semi-infinite gap.

Out-of-phase solitons are stable for positive or zero defects in the first gap.

Solitons can be stable above phase transition points of PT potentials.

Abstract

The existence and stability of defect solitons supported by parity-time (PT) symmetric superlattices with nonlocal nonlinearity are investigated. In the semi-infinite gap, in-phase solitons are found to exist stably for positive or zero defects, but can not exist in the presence of negative defects with strong nonlocality. In the first gap, out-of-phase solitons are stable for positive or zero defects, whereas in-phase solitons are stable for negative defects. The dependence of soliton stabilities on modulation depth of the PT potentials is studied. It is interesting that solitons can exist stably for positive and zero defects when the PT potentials are above the phase transition points.