Subwavelength-width optical tunnel junctions for ultracold atoms

TL;DR

This paper introduces a novel optical method to create ultranarrow potential barriers for ultracold atoms, enabling advanced control for quantum simulations and information processing.

Contribution

It presents a new approach to generate subwavelength optical barriers using nonlinear atomic responses and dark resonances, surpassing diffraction limits.

Findings

Barrier widths approach tens of nanometers

Technique enables precise control of atomic tunneling

Potential applications in quantum information protocols

Abstract

We propose a new method for creating far-field optical barrier potentials for ultracold atoms with widths that are narrower than the diffraction limit and can approach tens of nanometers. The reduced widths stem from the nonlinear atomic response to control fields that create spatially varying dark resonances. The subwavelenth barrier is the result of the geometric scalar potential experienced by an atom prepared in such a spatially varying dark state. The performance of this technique, as well as its applications to the study of many-body physics and to the implementation of quantum information protocols with ultracold atoms, are discussed, with a focus on the implementation of tunnel junctions.