An array of radiatively coupled emitters is an exciting new platform for generating, storing, and manipulating quantum light. However, the simultaneous positioning and tuning of multiple lifetime-limited emitters into resonance remains a significant challenge.  We reported the creation of superradiant and subradiant entangled states in pairs of lifetime-limited and sub-wavelength-spaced organic molecules by permanently shifting them into resonance with laser-induced tuning [1]. The molecules are embedded as defects in an organic nanocrystal. The pump light redistributes charges in the nanocrystal and dramatically increases the likelihood of resonant molecules. The frequency spectra, lifetimes, and second-order correlation agree with a simple quantum model. This scalable tuning approach with organic molecules provides a pathway for observing collective quantum phenomena in sub-wavelength arrays of quantum emitters.

[1] C Lange, E Daggett, V Walther, L Huang, and JD Hood, Nature Physics (2024)