A subwavelength atomic array switched by a single Rydberg atom

Enhancing light-matter coupling at the level of single quanta is essential for numerous applications in quantum science. The cooperative optical response subwavelength atomic arrays has been found to open new pathways such strong couplings, while simultaneously offering access multiple spatial modes light field. Efficient single-mode free-space reported, but control over outgoing fields remained elusive. Here, we demonstrate an atomically thin mirror formed by a array atoms free space using controlled ancilla atom excited Rydberg state. switching behavior admixture small fraction mirror, and consequently dipolar interactions with ancilla. Driving Rabi oscillations on atom, coherent transmission reflection array. These results represent step towards realization metasurfaces, demonstration atom-photon entanglement deterministic engineering states light.