Observation of single- and two-photon beating between independent Raman scattering

TL;DR

This paper demonstrates the observation of single- and two-photon beating between independent Raman scattering fields, revealing phase and dephasing effects influenced by atomic temperature, with implications for quantum interference studies.

Contribution

It reports the first observation of single- and two-photon beating in independent Raman fields and links dephasing to atomic temperature, advancing understanding of quantum interference in Raman processes.

Findings

Single-photon beating observed in a single realization.

Two-photon beating signal recovered via correlation measurement.

Dephasing depends on atomic medium temperature.

Abstract

By using spontaneous Raman processes in the high gain regime, we produce two independent Raman Stokes fields from an atomic ensemble. Temporal beating is observed between the two directly generated Stokes fields in a single realization. The beat frequency is found to be a result of an AC Stark frequency shift effect. However, due to the spontaneous nature of the process, the phases of the two Stokes fields change from one realization to another so that the beat signal disappears after average over many realizations. On the other hand, the beat signal is recovered in a two-photon correlation measurement, showing a two-photon interference effect. The two-photon beat signal enables us to obtain dephasing information in the Raman process. The dephasing effect is found to depend on the temperature of the atomic medium.