Fast and efficient preparation of 1D chains and dense cold atomic clouds

TL;DR

This paper presents a new experimental platform for rapidly preparing 1D chains and dense clouds of cold rubidium atoms, enabling advanced studies of structured and disordered atomic systems with high control and density.

Contribution

The authors introduce a novel setup combining high-resolution optics, a controllable telescope, and enhanced loading techniques to efficiently produce large atomic chains and dense clouds in free space.

Findings

Achieved preparation of 1D atomic chains with up to 100 atoms.

Created dense atomic clouds with peak densities of 10^15 atoms/cm^3.

Enabled studies of light-induced interactions in dense atomic samples.

Abstract

We report the efficient and fast ($\sim 2\mathrm{Hz}$) preparation of randomly loaded 1D chains of individual $^{87}$Rb atoms and of dense atomic clouds trapped in optical tweezers using a new experimental platform. This platform is designed for the study of both structured and disordered atomic systems in free space. It is composed of two high-resolution optical systems perpendicular to each other, enhancing observation and manipulation capabilities. The setup includes a dynamically controllable telescope, which we use to vary the tweezer beam waist. A D1 $\Lambda$-enhanced gray molasses enhances the loading of the traps from a magneto-optical trap. Using these tools, we prepare chains of up to $\sim 100$ atoms separated by $\sim 1 \mathrm{\mu m}$ by retro-reflecting the tweezer light, hence producing a 1D optical lattice with strong transverse confinement. Dense atomic clouds with peak densities up to $n_0 = 10^{15}\:\mathrm{at}/\mathrm{cm}^3$ are obtained by compression of an initial cloud. This high density results into interatomic distances smaller than $\lambda/(2\pi)$ for the D2 optical transitions, making it ideal to study light-induced interactions in dense samples.