Quantum interfaces with multilayered superwavelength atomic arrays

TL;DR

This paper explores multilayered superwavelength atomic arrays as quantum interfaces, showing that adding layers can suppress scattering losses and enhance atom-photon coupling efficiency through destructive interference, with practical implications for quantum memory.

Contribution

It introduces a multilayer atomic array design that reduces scattering losses and improves quantum light-matter coupling efficiency via destructive interference between layers.

Findings

Adding layers suppresses scattering losses through destructive interference.

Optimal efficiency occurs at small diffraction angles and interlayer separations.

Coupling inefficiency scales as N^{-1} with atom number per layer.

Abstract

We consider quantum light-matter interfaces comprised of multiple layers of two-dimensional atomic arrays, whose lattice spacings exceed the wavelength of light. While the coupling of light to a single layer of such a ``superwavelength" lattice is considerably reduced due to scattering losses to high diffraction orders, we show that the addition of layers can suppress these losses through destructive interference between the layers. Mapping the problem to a 1D model of a quantum interface wherein the coupling efficiency is characterized by a reflectivity, we analyze the latter by developing a geometrical optics formulation, accounting for realistic finite-size arrays. We find that optimized efficiency favors small diffraction-order angles and small interlayer separations, and that the coupling inefficiency of two layers universally scales as $N^{-1}$ with the atom number per layer $N$. We validate our predictions using direct numerical calculations of the scattering reflectivity and the performance of a quantum memory protocol, demonstrating high atom-photon coupling efficiency. We discuss the utility of our technique for applications in tweezer atomic arrays platforms.