Figure 10

The mean polariton number (a) and${\mathit{g}}_{\mathbf{2}}^{\mathbf{(}\mathbf{2}\mathbf{)}}$-function (b) of the central resonator in the strong driving regime,$\mathbf{\Omega }\mathbf{/}\mathit{\gamma }\mathbf{=}\mathbf{5}$, as a function of$\mathit{J}\mathbf{/}\mathit{\gamma }$and$\mathit{U}\mathbf{/}\mathit{\gamma }$. The plots show the results gained from equation (23). Due to the previously explained nature of our approach being a good approximation for lower tunneling strength, we are able to cover an additional regime compared to the Bogoliubov expansion, which broke down for higher values of the nonlinearity. (Compare with Fig. 8.)