Photon molecules in atomic gases trapped near photonic crystal waveguides

TL;DR

This paper explores creating photon molecules in atomic gases near photonic crystal waveguides by engineering atomic interactions via the waveguide's dispersion, enabling novel photon-photon bound states.

Contribution

It introduces a new method for inducing atomic interactions through photonic crystal waveguides, leading to the formation of photon molecules with potential for advanced quantum optics applications.

Findings

Demonstrated formation of photon bound states in atomic gases near photonic crystal waveguides.

Showed that dispersion engineering allows control over interaction strength and range.

Predicted the emergence of molecular-like potentials for photons.

Abstract

Realizing systems that support robust, controlled interactions between individual photons is an exciting frontier of nonlinear optics. To this end, one approach that has emerged recently is to leverage atomic interactions to create strong and spatially non-local interactions between photons. In particular, effective interactions have been successfully created via interactions between atoms excited to Rydberg levels. Here, we investigate an alternative approach, in which atomic interactions arise via their common coupling to photonic crystal waveguides. This technique takes advantage of the ability to separately tailor the strength and range of interactions via the dispersion engineering of the structure itself, which can lead to qualitatively new types of phenomena. As an example, we discuss the formation of correlated transparency windows, in which photonic states of a certain number and shape selectively propagate through the system. Through this technique, we show in particular that one can create molecular-like potentials that lead to molecular bound states of photon pairs.