A team of our scientists from the Quantum Technology Group in their research studied the interaction between light and matter in a system where a cloud of cold atoms is located inside an optical cavity, while excitation comes from an optical frequency comb—a source containing a large number of discrete, equally spaced frequencies.
The research was entirely conducted at the Institute of Physics, and the paper was published in the journal Physical Review Research.
Unlike standard experiments where one or only a few resonant cavity modes are considered, it is shown here that atoms can simultaneously affect a large number of longitudinal modes (on the order of a hundred). This influence manifests as a shift in the resonant frequencies of the modes and a change in light transmission through the cavity.
Crucially, these shifts are not the result of independent contributions from individual atoms, but arise from their joint, collective response to the electromagnetic field in the cavity. In other words, the system behaves as a whole in which the atoms and light modes are interconnected, and in certain regimes, it exhibits nonlinear behavior. One such phenomenon is optical bistability, where the system can stably exist in two different states under identical external conditions.
The importance of this work lies in the significant expansion of experimental possibilities in the study of light-matter interaction by introducing simultaneous access to a large number of frequency components within the same optical cavity. On this platform, it is possible to study collective phenomena under well-controlled conditions, with the possibility of precise tuning of frequencies, excitation strength, and properties of the atomic cloud.
Such an approach represents a further step toward researching many-body physics in an expanded context and the analysis of collective excitations. Systems of this kind have the potential to serve as a platform for modeling more complex quantum systems, as well as for developments in precision spectroscopy and the control and manipulation of atoms and molecules.
The full paper is available at the link: doi.org/10.1103/fy4n-mj4d
