Unconventional photon blockade from bimodal driving and dissipations in coupled semiconductor microcavities

We propose an unconventional photon blockade scheme in coupled semiconductor microcavities embedded in a nonlinear Kerr medium in the presence of photon leakage and bimodal driving on two cavity modes, which consists of two spatially overlapping single-mode semiconductor cavities with cross-Kerr nonlinearity and two-photon tunneling. A detailed analysis is derived for the exact optimal conditions for strong photon antibunching with weak Kerr nonlinearities. It is very important to find the transition of the structures of the solution for the optimal detuning from the quartic equation to the cubic equation when changing the two complex driving fields appropriately. The transition originates from the second driving field that compensates the numbers of interference paths reaching a two-photon state. This unconventional photon blockade can be realized by coupled photonic crystal cavities filled with a nonlinear Kerr medium. This implies that nonlinear Kerr medium systems can be used to generate tunable single-photon sources by tuning the strength and relative phase of two complex driving fields under weak Kerr nonlinearity.