Intensity-field correlation of single-atom resonance fluorescence

TL;DR

This paper presents an experimental measurement of the intensity-field correlation in resonance fluorescence from a single trapped Ba+ ion, revealing non-classical behavior and wave-particle duality at the single-atom level.

Contribution

It introduces a novel measurement of the field of a radiating dipole in a single atom, demonstrating non-classical correlations and wave-particle duality.

Findings

Direct measurement of the dipole field of a single atom.

Observation of strong non-classical intensity-field correlations.

Demonstration of wave-particle duality at the single-photon level.

Abstract

We report measurements of an intensity-field correlation function of the resonance fluorescence of a single trapped Ba+ ion. Detection of a photon prepares the atom in its ground state and we observe its subsequent evolution under interaction with a laser field of well defined phase. We record the regression of the resonance fluorescence source field. This provides a direct measurement of the field of the radiating dipole of a single atom and exhibits its strong non-classical behavior. In the experimental setup an interference measurement is conditioned on a fluorescence photon detection. The third-order correlation function thus recorded demonstrates an aspect of wave-particle duality at the single-atom, single-photon level.