Light-induced, fictitious magnetic trapping of cold alkali atoms using an optical tweezers-nanofiber hybrid platform

TL;DR

This paper introduces a novel light-induced magnetic trapping method for cold rubidium atoms using an optical nanofiber and tweezers, enabling precise control of atom position and trap characteristics for quantum technology.

Contribution

It demonstrates a new hybrid trapping scheme combining optical tweezers and nanofiber-guided fields to manipulate atom-surface distance and trap parameters.

Findings

Trap position tunable over hundreds of nanometers.

Trap depth and frequencies can be controlled via optical power adjustments.

Potential for studying atom-surface interactions and quantum interfaces.

Abstract

We present a magnetic trapping scheme for cold 87Rb atoms based on light-induced fictitious magnetic fields generated by the evanescent field of an optical nanofiber (ONF) integrated with an optical tweezers. We calculate and compare the trapping potentials for both Gaussian and Laguerre-Gaussian modes of the tweezers beam, combined with a quasi-linearly polarized ONF-guided field. Based on the optical powers in the tweezers and ONF modes, we analyze the trap depths and the positions of the potential minima from the nanofiber surface. We show that, by varying the optical powers in the two fields, the trap position can be tuned over several hundred nanometers, while simultaneously influencing the trap depth and trap frequencies. Such control over atom-surface position is essential for studying distance-dependent effects on atoms trapped near a dielectric surface and optimizing atom-photon interfaces for quantum technology applications.