Abstract: The dressed states of the single atom-cavity system were described and Hilbert space was truncated t-photon transition process. By solving the master equation of the system, we calculated the energy level shift caused by two-photon resonance transition, and calculated the second-order correlation function of photon, which confirmed the existence of photon anti-bunching effect under given parameters.

Key words: photon blockade, correlation function, anti-bunching effect, J-C model