Universal Photon Blockade

Photon blockades are traditionally classified into conventional and unconventional types, depending on distinct physical mechanisms. Regarding the cavity decay rate κ, the conventional photon blockade takes place under strong nonlinearity condition (g>κ), whereas the unconventional photon blockade occurs in the regime of weak nonlinearity (g<κ). We here propose how to derive an optimal condition for photon blockade utilizing a two-photon Jaynes-Cummings model. Under this condition, the equal-time second-order correlation function reaches its minimum, leading to photon antibunching in both conventional and unconventional photon blockade regimes (g>κ and g<κ), even in g∼κ. This characteristic is termed universal photon blockade. By comparing it with the conventional and the unconventional photon blockades in the weak-driving limit, the advantages of universal photon blockade are revealed. Our proposal paves an avenue towards the future study of photon blockades and has potential applications in generating antibunched photons.