Nonlinear conical diffraction in superhoneycomb lattice induced in a photorefractive crystal

We report nonlinear conical diffraction in the superhoneycomb lattice, which is an edge-centered honeycomb lattice, induced in a photorefractive crystal. This system is of special interest, as it represents a hybrid fermionic – bosonic physical system. When nonlinearity is imposed, conical diffraction from a fermionic Dirac cone will change from circular diffraction rings, formed by small hexagons, into a triangular arrangement of hexagons. But from the bosonic Dirac cone, conical diffraction changes into elliptic diffraction rings of different inner symmetries, with the outer ring intensity damped.