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, H.; Kottos, Tsampikos; Kovanis, Vassilios; and Christodoulides, Demetrios N., "Exceptional-point dynamics in photonic honeycomb lattices with PT symmetry" (2012). Physics and Astronomy Faculty Publications and Presentations. 300.
Physical Review A