Kerr-nonlinearity enhanced conventional photon blockade in a second-order nonlinear system.

The conventional photon blockade (CPB) for high-frequency mode is investigated in a second-order nonlinear system with Kerr nonlinearity. By solving the master equation and calculating the zero-delay-time second-order correlation function g(0), we obtain that strong photon antibunching can be achieved in this scheme. The optimal condition for strong antibunching is also calculated analytically and discussed in detail. We find that the Kerr nonlinearity can largely enhance the CPB effect in the high-frequency mode, and this scheme is not sensitive to the reservoir temperature. In addition, when compared with the linear coupled system, the system has obvious advantages in CPB implementation.