PT-symmetric non-Hermitian zigzag-edged ribbon of bilayer photonic graphene

• Published in: Results in physics 2022-03, Vol.34, p.105274, Article 105274
• Main Authors: Zhang, Lian-Lian, Li, Jia-Rui, Zhang, Di, Xu, Tong-Tong, Cui, Wei-Bin, Gong, Wei-Jiang
• Format: Article
• Language: English
• Subjects: Band structure; Bilayer photonic graphene; Edge states; symmetry; Zigzag-edged ribbon
• ISSN: 2211-3797; 2211-3797
• DOI: 10.1016/j.rinp.2022.105274

In this paper, we perform the theoretical investigation of the band structure of the non-Hermitian zigzag-edged ribbon of the bilayer photonic graphene by considering the presence of PT-symmetric imaginary potentials. It is found that such potentials cause the energies of edge states to display prominent features, manifested as their extensive distribution in the parameter region and the modification of topological properties. When interlayer level detuning is incorporated, PT symmetry is destroyed, but two new pairs of edge states have an opportunity to arise that can induce complex Dirac cones. All these results imply that PT-symmetric imaginary potentials are effective mechanisms to modify the band structure properties of the zigzag-edged ribbon of bilayer photonic graphene. •We study the band of the non-Hermitian zigzag-edged ribbon of the bilayer photonic graphene.•PT symmetry causes the energy band of this system to exhibit prominent features.•It shows the band-structure deformation around Dirac point and various edge states.•Strengthening PT-symmetric potentials induces one pair of edge states with purely real energies.•PT-symmetric potentials are effective to modify the band of bilayer photonic graphene ribbon.