Full Optical Control of Topological Transitions in Polariton Chern   Insulator Analog
  Exciton-polariton lattices allow to implement topologically protected photonic edge states at optical frequencies. Taking advantage of the interacting character of polaritons, we show that several topological phases, belonging to the Quantum Anomalous Hall family, can occur in polariton graphene with the TE-TM spin-orbit coupling and an effective Zeeman field. This Zeeman field can be entirely controlled by the non-linearity of the macro-occupied mode created by circularly polarized resonant pumping. The topological phases found are distinct from the ones of normal graphene in presence of a combination of Rashba and Zeeman field. 
O.Bleu, D. D. Solnyshkov, G. Malpuech
cond-mat.mes-hall