Tunable directional emission and collective dissipation with quantum metasurfaces

TL;DR

This paper explores how quantum metasurfaces made of atomic arrays can be engineered to produce tunable directional emission and collective dissipation, with potential applications in quantum information processing.

Contribution

It introduces a method to control emission directionality and collective dissipation in atomic arrays by optimizing geometry and atomic positioning, including entangled clusters and bilayers.

Findings

Optimal array geometries for directional emission identified

Efficient coupling achieved through specific atomic positions

Emission directionality controlled via dipole orientation

Abstract

Subwavelength atomic arrays, recently labeled as quantum metamaterials, have emerged as an exciting platform for obtaining novel quantum optical phenomena. The strong interference effects in these systems generate subradiant excitations that propagate through the atomic array with very long lifetimes. Here, we demonstrate that one can harness these excitations to obtain tunable directional emission patterns and collective dissipative couplings when placing judiciously additional atoms nearby the atomic array. For doing that, we first characterize the optimal array geometry to obtain directional emission patterns. Then, we characterize the best atomic positions to couple efficiently to the subradiant metasurface excitations, and provide several improvement strategies based on entangled atomic clusters or bilayers. Afterwards, we also show how the directionality of the emission pattern can be controlled through the relative dipole orientation between the auxiliary atoms and the one of the array. Finally, we benchmark how these directional emission patterns translate into to collective, anisotropic dissipative couplings between the auxiliary atoms by studying the lifetime modification of atomic entangled states.