Exploring waveguide QED and collective radiative dynamics with matter waves

Super- and subradiance are usually well described by assuming instantaneous photon-mediated dissipative interactions. However, this obscures the dynamical role that radiation can play in spatially extended systems. In this talk, I discuss recent experiments [1] with a platform of matter-wave quantum emitters [2] in which the carriers of interactions are not photons but slow atomic matter waves. This allows access to novel aspects of Dicke physics in waveguide QED. By preparing arrays of emitters with atomic excitations in timed-Dicke (superfluid) and fully inverted (Mott insulating) initial states that are radiatively coupled to a 1D bath, we observe near-perfect subradiance and directional superradiance, examine non-Markovian effects arising from propagation delays, and directly detect the formation of coherence across the emitters. By merging concepts of quantum optics, atomic physics, and condensed matter physics, our work provides both fundamental insights and novel connections between fields.

[1] Y. Kim, A. Lanuza, and D. Schneble, Nature Physics 21, 70 (2025)

[2] L. Krinner, M. Stewart, A. Pazmino, J. Kwon and D. Schneble, Nature 559, 589 (2018)