Collective inhibition of light scattering from atoms into an optical cavity at a magic frequency

TL;DR

This paper reports the discovery of a magic frequency in cold rubidium atoms where light scattering into an optical cavity is suppressed due to quantum interference, revealing new control over atom-photon interactions.

Contribution

The study identifies a new magic frequency in ${}^{87}$Rb atoms where both Rayleigh and Raman scattering are suppressed by quantum interference in a strongly coupled atom-cavity system.

Findings

Scattering into the cavity is suppressed at 185 MHz below the F=2→F'=3 transition.

Both Rayleigh and Raman scattering are extinguished at the magic frequency.

A separate magic frequency around -506 MHz suppresses only Raman scattering.

Abstract

We report on the observation of a new magic frequency within the hyperfine structure of the D2 line of ${}^{87}$Rb atoms at which the scattering of light into a high-finesse cavity is suppressed by an interplay between quantum interference and the strong collective coupling of atoms to the cavity. Scattering from a cloud of laser-driven cold atoms into the cavity was measured in a polarization sensitive way. We have found that both the Rayleigh and Raman scattering processes into the near-resonant cavity modes are extinguished at 185 MHz below the F=2$\leftrightarrow$F'=3 transition frequency. This coincidence together with the shape of the observed spectral dip imply that the effect relies on a quantum interference in the polariton excitations of the strongly coupled combined atom-photon system. We have also demonstrated the existence of a magic frequency around -506 MHz, where only the Raman scattering is suppressed due to a quantum interference effect at the single-atom level.