Nanofiber-Based Double-Helix Dipole Trap for Cold Neutral Atoms

TL;DR

This paper proposes a novel nanofiber-based double-helix optical trap for cold atoms, enabling flexible, one-dimensional confinement and potential modulation for advanced cold-atom experiments.

Contribution

It introduces a simple method to create a double-helix trapping potential inside an optical nanofiber using three laser fields, with tunable geometry.

Findings

Achieves one-dimensional confinement of cesium atoms at microkelvin temperatures.

Demonstrates modulation of the double-helix geometry by varying nanofiber diameter.

Provides a feasible experimental setup for complex cold-atom trapping configurations.

Abstract

A double-helix optical trapping potential for cold atoms can be straightforwardly created inside the evanescent field of an optical nanofiber. It suffices to send three circularly polarized light fields through the nanofiber; two counterpropagating and far red-detuned with respect to the atomic transition and the third far blue-detuned. Assuming realistic experimental parameters, the transverse confinement of the resulting potential allows one to reach the one-dimensional regime with cesium atoms for temperatures of several \muK. Moreover, by locally varying the nanofiber diameter, the radius and pitch of the double-helix can be modulated, thereby opening a realm of applications in cold-atom physics.