Ultracold molecule assembly with photonic crystals

Abstract

Photoassociation (PA) is a powerful technique to synthesize molecules directly and continuously from cold and ultracold atoms into deeply bound molecular states. In freespace, however, PA efficiency is constrained by the number of spontaneous decay channels linking the initial excited molecular state to a sea of final (meta)stable rovibronic levels. Here, we propose a novel scheme based on molecules strongly coupled to a guided photonic mode in a photonic crystal waveguide that turns PA into a powerful tool for near deterministic formation of ultracold molecules in their ground rovibrational level. Our example shows a potential ground state molecule production efficiency 90% > , and a saturation rate 10 6 > molecules per second. By combining state-of-the-art cold atomic and molecular physics with nanophotonic engineering, our scheme presents a novel experimental package for trapping, cooling, and optically manipulating ultracold molecules, thus opening up new possibilities in the direction of ultracold chemistry and quantum information.

Cavity-controlled formation of ultracold molecules

“…The parameters g max , Γ, C max are derived for the transitions between vibrational states of the (1) 3 Π g and a 3 Σ u potentials in Rb 2 . Here, d el ≈3×10 −29 C m, see [6,18].…”

“…We make use of the fact that strong confinement of the electromagnetic field modes around a molecule can control its spontaneous emission and thus its final quantum state. Our scheme is related to previous proposals for a molecular matter-wave amplifier in an optical cavity [5] or for coupling atoms to broadband photonic crystal waveguides [6].…”

Resonator-assisted single molecule quantum state detection

“…1(b), in which a single-photon, short-range photoassociation has been utilized for ground state molecule synthesis directly from cold atoms [30]. Using an optical cavity or a photonic crystal waveguide to radiatively enhance the synthesis efficiency has recently been discussed [31,32]. These recent developments makes Rb 2 a good candidate to demonstrate resonator-enhanced single molecule detection.…”

Integrating two-photon nonlinear spectroscopy of rubidium atoms with silicon photonics

“…In recent years, several phenomena such as chiral transport of the photons and their interactions have been studied in a hybrid system of cold atoms interfaced with optical fibers [16][17][18][19][20][21], and photonic crystal waveguides and cavities [22][23][24][25]. Although progress on the miniaturization of cold atom experiments has been reported [26], combining them in cavity networks is still a challenge.…”