Resonance interaction of light with molecules and the energy spin method

Alexander A. Ivanov, V. V. Parail, T. K. Soboleva

William G. Tobias, Kyle Matsuda, Jun-Ru Li +5 more

Microscopic control over polar molecules with tunable interactions enables the realization of distinct quantum phenomena. Using an electric field gradient, we demonstrated layer-resolved state preparation and imaging of ultracold potassium-rubidium molecules confined to two-dimensional planes in an optical lattice. The rotational coherence was maximized by rotating the electric field relative to the light polarization for state-insensitive trapping. Spatially separated molecules in adjacent layers interact through dipolar spin exchange of rotational angular momentum; by adjusting these interactions, we regulated the local chemical reaction rate. The resonance width of the exchange process vastly exceeded the dipolar interaction energy, an effect attributed to thermal energy. This work realized precise control of interacting molecules, enabling electric field microscopy on subwavelength scales and allowing access to unexplored physics in two-dimensional systems.

Philippe Lalanne

Lange, Christian M

Quantum light-matter interactions form the basis of many quantum technologies and much fundamental research. Organic molecules are an impressive platform for the generation of quantum light, both as single photon emitters and as collective systems. In this work, I investigate quantum light-matter interactions with molecules of dibenzoterrylene in crystals of anthracene. I outline methods to grow dibenzoterrylene-doped anthracene crystals, and I characterize the optical properties of cryogenically cooled molecules. I prepare collective systems composed of pairs of molecules interacting through their free-space electromagnetic fields. I demonstrate a method to tune interacting molecules into resonance to form superradiant and subradiant collective states. Finally, I present a platform for solid-state cavity QED based on molecules of dibenzoterrylene coupled to a nanophotonic cavity. This demonstration establishes a route toward scalable deterministic photon generation with molecules. I also tune pairs of cavity-coupled molecules into resonance to form distributed collective states, opening the door to cavity-mediated many-body interactions.

Hermann Haken, Hans Christoph Wolf

Olivier Émile, Fabien Bretenaker, A. Le Floch

The existence of a novel resonance in the modulation of the fluorescence light emitted by an atom or a molecule when coherently excited by a rapidly rotating linearly polarized light beam is predicted. Such resonances are experimentally observed due to a transfer of coherence from light to atoms or molecules, via either stimulated emission or absorption of light, without having to shift the positions of the levels by an external perturbation. These resonances directly permit the measurement of energy level lifetimes, even in the case where usual magnetic resonance methods would require the use of large magnetic fields.