Daniel Gonçalves (ICFO)

We explore the combination of sub-wavelength, two-dimensional atomic arrays and
Rydberg interactions as a powerful platform to realize strong, coherent interactions
between individual photons with high fidelity. In particular, the spatial ordering of the
atoms guarantees efficient atom-light interactions without the possibility of scattering
light into unwanted directions, for example, allowing the array to act as a perfect mirror
for individual photons. In turn, Rydberg interactions enable single photons to alter the
optical response of the array within a potentially large blockade radius, which can
effectively punch a large “hole” for subsequent photons. We show that such a system
enables a coherent photon-photon gate or switch, with an error scaling that is
significantly better than the best known scaling in a disordered ensemble.