Optical focusing of Bose-Einstein condensates

TL;DR

This paper presents a theoretical study of optical focusing of Bose-Einstein condensates onto surfaces, predicting nanometer-scale focus with high density, using a Gaussian variational method validated by numerical simulations.

Contribution

It introduces a Gaussian variational approach that accounts for interactions and losses, providing analytical predictions aligned with numerical results for focused BEC profiles.

Findings

Focused condensates of 10^5 atoms can reach ~10 nm widths.

Peak densities can exceed 10^5 atoms/μm^2.

Analytical results agree with numerical simulations.

Abstract

We theoretically investigate the optical focusing of a rubidium Bose-Einstein condensate onto a planar surface. Our analysis uses a Gaussian variational method that includes the effects of two-body atom-atom interactions and three-body recombination losses. The essential factors such as the width, peak density and atom loss rate of the focused BEC profile on the surface are investigated and compared to Gross-Pitaevskii numerical simulations. We find a reasonable agreement in the results between our analytical approach and the numerical simulations. Our analysis predicts that condensates of $10^5$ atoms could be focused down to $\sim 10$nm widths, potentially allowing nanometer-scale atomic deposition with peak densities greater than $10^5$ atoms/$\mu$m$^2$.