Title: Oral: Non-Markovian Quantum Emitter Interactions via a Structured Reservoir

Waveguides enable efficient coupling between distant quantum emitters, with nanophotonic structures facilitating engineerable photonic dispersion properties. Dispersion engineering can decrease the speed of light by several orders of magnitude compared to free space, allowing for long-ranged interactions between quantum emitters and exotic many-body light-matter interactions. In such regimes, the dynamics of quantum emitters becomes non-Markovian owing to the memory effects of the slow electromagnetic fields mediating the interaction.

We explore the collective behavior of two distant quantum emitters coupled through a waveguide with nonlinear dispersion properties. We demonstrate the modifications to collective dynamics beyond regular superradiance and subradiance phenomena and discuss the effects of dispersion engineering on the onset of collective behavior. Such waveguide mediated non-Markovian collective atom-field interactions are relevant to distributed quantum sensing and metrology protocols and quantum networks.