Photonic realization of PT-symmetric quantum field theories

A photonic realization of the quantum field theoretical Lee model, describing the strong coupling of two neutral fermions and a neutral scalar boson field, is proposed in the ghost regime, where the Lee Hamiltonian is non-Hermitian but PT symmetric. Our optical system, which is based on light transport in an engineered semi-infinite waveguide lattice, could provide an accessible laboratory system to simulate PT-symmetric quantum field theories and to visualize the appearance and role of ghost states in the dynamics.