We theoretically investigate the flow of electromagnetic waves in complex honeycomb photonic lattices with local PT symmetries. Such PT structure is introduced via a judicious arrangement of gain and loss across the honeycomb lattice, characterized by a gain and loss parameter γ. We found a class of conical diffraction phenomena where the formed cone is brighter and travels along the lattice with a transverse speed proportional to √γ.
Ramezani, Hamidreza, et al. “Exceptional-Point Dynamics in Photonic Honeycomb Lattices with PT Symmetry.” Physical Review A, vol. 85, no. 1, American Physical Society, Jan. 2012, p. 013818, doi:10.1103/PhysRevA.85.013818.
Physical Review A