PT-symmetric non-Hermitian AB-stacked bilayer honeycomb photonic lattice

We theoretically investigate the band structure of the parity-time ( P T )-symmetric non-Hermitian bilayer honeycomb photonic lattice by considering the co-existence of onsite energy detuning and P T -symmetric imaginary potentials. It is found that P T symmetry causes the system’s energy spectra to display salient features, which include various energy-band degeneracies and deformation of the band structure in the vicinity of the Dirac point. Also, the P T -symmetry breaking can be modulated by introducing strain to the system. The findings in this work can help in understanding the band structures of P T -symmetric bilayer honeycomb photonic-lattice systems.