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

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.