Interaction of light with planar lattices of atoms: Reflection, transmission and cooperative magnetometry

TL;DR

This paper investigates how light interacts with two-dimensional atomic lattices, revealing collective phenomena like super-atom behavior, narrow resonances, and a new cooperative magnetometry technique that surpasses single-atom limitations.

Contribution

It introduces a super-atom model for atomic lattices, analyzes their spectral response, and proposes a cooperative magnetometry protocol leveraging collective narrow linewidths.

Findings

Super-atom model accurately describes lattice optical response.

Lattice arrays can be used to create a highly sensitive magnetometer.

Resonance linewidths are significantly narrower due to collective interactions.

Abstract

We study strong light-mediated resonant dipole-dipole interactions in two-dimensional planar lattices of cold atoms. We provide a detailed analysis for the description of the dipolar point emitter lattice plane as a "super-atom", whose response is similar to electromagnetically-induced transparency, but which exhibits an ultra-narrow collective size-dependent subradiant resonance linewidth. The super-atom model provides intuitively simple descriptions for the spectral response of the array, including the complete reflection, full transmission, narrow Fano resonances, and asymptotic expressions for the resonance linewidths of the collective eigenmodes. We propose a protocol to transfer almost the entire radiative excitation to a single correlated subradiant eigenmode in a lattice and show that the medium obtained by stacked lattice arrays can form a cooperative magnetometer. Such a magnetometer utilizes similar principles as magnetometers based on the electromagnetically-induced transparency. The accuracy of the cooperative magnetometer, however, is not limited by the single-atom resonance linewidth, but the much narrower collective linewidth that results from the strong dipole-dipole interactions.