Quantum decay rates trigger a phase transition in superradiance

Raphael Holzinger at the University of Innsbruck, Nico S. Bassler at TU Darmstadt, and colleagues have developed a method to model Dicke superradiance with multiple, competing decay channels and to tune the rates of those channels. Their symbolic quantum-trajectory construction yields closed time-domain solutions, predicting the behavior of superradiance as finite combinations of exponential terms regardless of the number of emitters or decay rates involved. The work unifies existing single-channel dynamics and provides a tool for experiments using engineered reservoirs with multiple decay paths, where the team finds that a ground-state distribution resembles a first-order phase transition when channel-rate ratios equal unity. Researchers have demonstrated a method to predict the behavior of Dicke superradiance, a collective emission of light from multiple excited atoms, when influenced by two or more competing decay pathways, each with independently tunable rates. The work provides closed-form solutions describing the system’s evolution, meaning the populations and observable properties can be calculated at any point in time without complex numerical simulations, regardless of the number of emitting atoms.…