Fig. 1. Model of a two-atom cavity QED system

Fig. 2. Average photon number and two-photon excitation spectrum in cavity

Fig. 3. Second order correlation function of cavity field varies with the detuning of laser field frequency and cavity frequency

Fig. 4. Relationship between diatomic excitation probability and cavity leakage rate with different ϕ

Fig. 5. Relationship between scaling factor of diatomic excitation probability and single atomic excitation probability and cavity leakage rate with different ϕ