Dicke superradiance in arrays of multilevel atoms*

We investigate Dicke superradiance with multilevel atoms. Dicke superradiance is a dissipative many-body phenomenon where excited atoms collectively emit a short intense burst of light. While this is well understood for two-level systems in a cavity, our work involves extended arrays in free space. In previous work, we showed that Dicke superradiance generically occurs for two-level systems in arrays, provided that the distance between them is sufficiently small. Here, we consider atoms that can decay into multiple states and show that a superradiant burst can be emitted on all transitions. We develop constraints on the relative rates of each transition and on the geometry of the atomic ensemble, and show that the intensity emitted in certain directions features a superradiant burst in arrays of large interatomic spacing. Our results provide a guide to explore this many-body phenomenon in state-of-the-art experimental setups.