Defect solitons in defective PT potentials with real part of dual-frequency lattices

TL;DR

This paper investigates the stability and existence of defect solitons in defective parity-time potentials with dual-frequency lattices, revealing how defect type influences soliton stability in different spectral gaps.

Contribution

It provides new insights into how positive and negative defects affect the stability regions of defect solitons in PT potentials with dual-frequency lattices.

Findings

Positive defects stabilize certain symmetric/antisymmetric solitons in the semi-infinite gap.

Negative defects allow stable symmetric/antisymmetric solitons in the first gap.

All antisymmetric solitons are unstable in the semi-infinite gap regardless of defect type.

Abstract

We address the properties of defect solitons (DSs) in defective parity-time potentials with real part of dual-frequency lattices. The impact of defect on stability regions of DSs was considered. For positive defects, DSs whose real/imaginary parts are symmetric/antisymmetric (SA) functions of position are always stable in the semi-infinite gap and nonexistent in the first gap. While for negative defects, in semi-infinite gap, the SADSs are stable in most of their existence region besides low power region, but in the first gap, all the SADSs are stable. The ASDSs are unstable in the whole semi-infinite gap regardless of defects, but can be stable in the low power region for positive defects.