The Atomic Lighthouse Effect

TL;DR

This paper explores how magnetic field gradients can locally steer light in cold atomic clouds, revealing a lighthouse-like deflection effect that varies with optical density and collective atomic interactions.

Contribution

It introduces the atomic lighthouse effect, demonstrating how local Zeeman tuning influences light deflection, especially in the single-scattering regime and in dense atomic samples.

Findings

Maximum deflection occurs in the single-scattering regime.

Collective effects reduce deflection in dense samples.

Linewidth increase diminishes magnetic field's steering efficiency.

Abstract

We investigate the deflection of light by a cold atomic cloud when the light-matter interaction is locally tuned via the Zeeman effect using magnetic field gradients. This "lighthouse" effect is strongest in the single-scattering regime, where deviation of the incident field is largest. For optically dense samples, the deviation is reduced by collective effects, as the increase in linewidth leads to a decrease of the magnetic field efficiency.