From matter-wave quantum emitters to polariton physics in an optical lattice

We present an overview of our group's recent work with a flexible, well-controlled platform for studies of radiative phenomena with matter waves. Starting from experiments to observe spontaneous emission into vacuum [1], we have explored the decay of matter-wave quantum emitters coupled to a tunable analog of a photonic crystal [2]. A theoretical analysis including multiband effects in an array of emitters achieves very good agreement with the full set of our data and allows us to extract a polaritonic band structure [3]. We have recently probed the presence of such matter-wave quasi-particles and studied their transport and interaction properties [4] which provides opportunities for studies of exciton-polariton physics.