Bloch polaritons in arrayed two-level atoms: collective emission and anomalous transport

We present a unified and transparent theoretical framework for two longstanding phenomena in light-matter systems: collective emission and anomalous transport. Although both subjects have been extensively studied, we revisit them using a field-theoretical approach that solves the dressed Bloch wave functions of photons and electrons in an irradiated array of two-level atoms. This treatment reveals that the evolution of emission with irradiation frequency-from subradiance to superradiance-is directly encoded in the dressed photon momentum, which captures radiative decay and coherence. At the same time, photon-mediated interactions give rise to unconventional transport responses, including near-zero and even negative resistivity, whose microscopic origin can be consistently explained through the self-energy of the dressed electron. Framed in terms of Bloch polaritons, our results establish a direct link between radiative decay, cooperative interference, and transport anomalies, providing fresh insights into engineered light-matter platforms with tunable emission and transport properties.