Signatures of single site addressability in resonance fluorescence spectra

TL;DR

This paper investigates how resonance fluorescence spectra can reveal single-site addressability in optical lattices, showing that asymmetries in the spectrum indicate laser targeting only one atom due to dipole interactions.

Contribution

It demonstrates that spectral asymmetries serve as signatures of single-site laser addressing, advancing methods for precise atomic control in optical lattice experiments.

Findings

Single site addressing causes spectral asymmetry.

Dipole-dipole interactions influence fluorescence spectra.

Spectral shape can verify laser targeting accuracy.

Abstract

Pioneering methods in recent optical lattice experiments allow to focus laser beams down to a spot size that is comparable to the lattice constant. Inspired by this achievement, we examine the resonance fluorescence spectra of two-level atoms positioned in adjacent lattice sites and compare the case where the laser hits only one atom (single site addressing) with cases where several atoms are illuminated. In contrast to the case where the laser hits several atoms, the spectrum for single site addressing is no longer symmetric around the laser frequency. The shape of the spectrum of fluorescent light can therefore serve as a test for single site addressing. The effects we find can be attributed to a dipole-dipole interaction between the atoms due to mutual exchange of photons.