Tailoring cooperative emission in molecules: superradiance and subradiance from first-principles simulations

Cooperative optical effects provide a pathway to both the amplification (superradiance) and the supression (subradiance) of photon emission from electronically excited states. These captivating phenomena offer a rich variety of possibilities for photonic technologies aimed at electromagnetic energy manip- ulation, including lasers and high-speed emitting devices in the case of superradiance, or optical energy storage in that of sub- radiance. The employment of molecules as the building pieces in these developments requires a precise understanding of the roles of separation, orientation, spatial distribution and applied fields, which remains challenging for theory and experiments. These questions are addressed here through ab initio quantum dynamics simulations of collective emission on the basis of a novel semiclassical formalism and time-dependent DFT. By es- tablishing the configurations leading to decoherence and how the fine-tuning of a pulse can accumulate or release optical energy in H2 arrays, this report provides fundamental insight toward the design of real superradiant and subradiant devices.