Method for generating a photonic NOON state with quantum dots in coupled nanocavities

We propose a method to generate path-entangled NOON-state photons from quantum dots and coupled nanocavities. In the systems we considered, cavity mode frequencies are tuned close to the biexciton two-photon resonance. Under appropriate conditions, the system can have the target NOON state in the energy eigenstate, as a consequence of destructive quantum interference. The NOON state can be generated by a resonant laser excitation. This method, first introduced for a two-photon NOON state ($N=2$), can be extended toward a higher NOON state ($Ng2$) based on our recipe, which is applied to the case of $N=4$ as an example.