Selective Radiance in Super-Wavelength Atomic Arrays

A novel way to create efficient atom-light interfaces is to engineer collective atomic states that selectively radiate into a target optical mode by suppressing emission into undesired modes through destructive interference. While it is generally assumed that this approach requires dense atomic arrays with sub-wavelength lattice constants, here we show that selective radiance can also be achieved in arrays with super-wavelength spacing. By stacking multiple two-dimensional arrays we find super-wavelength mirror configurations where one can eliminate emission into unwanted diffraction orders while enhancing emission into the desired specular mode, leading to near-perfect reflection of weak resonant light. These super-wavelength arrays can also be functionalized into efficient quantum memories, with error probabilities on the order of ~1 for a trilayer with only around ~100 atoms per layer. Relaxing the previous constraint of sub-wavelength spacing could potentially ease the technical requirements for realizing efficient atom-light interfaces, such as enabling the use of tweezer arrays.