Collectively Enhanced Universal Photon Blockade

High-purity and bright single-photon sources are important for quantum information processing and precision measurement. We propose a collectively enhanced universal photon-blockade scheme in a multi-emitter two-photon Tavis–Cummings system. Independent coherent drives of the cavity and collective emitter enable destructive interference between two-photon excitation pathways, while collective coupling supplies level anharmonicity. Full-quantum master-equation simulations, the Holstein–Primakoff approximation, and a non-Hermitian probability-amplitude analysis yield the optimal conditions: cavity resonance together with phase and amplitude matching. Compared with a purely collective blockade, the proposed scheme lowers $g^{(2)}(0)$, and essentially preserves the single-photon population. As the emitter number $N$ increases, the optimal point remains at ${\mathrm{\Delta }}_c=0$, while the minimum correlation follows $g_{\min }^{}(0)\propto N^{-2}$. By contrast, unconventional photon blockade shifts away from resonance as $N$ increases, limiting its purity improvement and brightness. In the weak-drive regime, universal blockade obeys $g^{(2)}(0)\propto {\epsilon }_a^2$, owing to a higher-order bypass through the three-excitation manifold. The drive strength therefore provides an additional purity–brightness control, although the interference mechanism makes the scheme more sensitive to dissipation-rate mismatch. Our results establish a scalable route to bright, high-purity, and tunable single-photon emission in multi-emitter cavity-QED systems.