Single atom in a superoscillatory optical trap

TL;DR

This paper demonstrates a novel optical trapping technique using superoscillations to create subwavelength hotspots, enabling precise single-atom manipulation beyond traditional diffraction limits.

Contribution

It introduces a superoscillatory optical trap that allows continuous tuning from a standard focus to a subwavelength hotspot, surpassing diffraction constraints.

Findings

Successfully trapped a single ultracold atom in a superoscillatory hotspot.

Achieved continuous tuning of the trap size from diffraction-limited to subwavelength.

Potential applications in quantum simulation and single-molecule studies.

Abstract

Optical tweezers have become essential tools to manipulate atoms or molecules at a single particle level. However, using standard diffracted-limited optical systems, the transverse size of the trap is lower bounded by the optical wavelength, limiting the application range of optical tweezers. Here we report trapping of single ultracold atom in an optical trap that can be continuously tuned from a standard Airy focus to a subwavelength hotspot smaller than the usual Abbe's diffraction limit. The hotspot was generated using the effect of superoscillations, by the precise interference of multiple free-space coherent waves. We argue that superoscillatory trapping and continuous potential tuning offer not only a way to generate compact and tenable ensembles of trapped atoms for quantum simulators but will also be useful in single molecule quantum chemistry and the study of cooperative atom-photon interaction within subwavelength arrays of quantum emitters.