Date: Monday, October 12

Presenter: Dr. Jonathan Weinsten
Host: Dr. Daniel Steck

Cryogenically-cooled atoms and molecules for nonlinear
optics and cold chemistry

We use laser ablation and cryogenic helium buffer-gas cooling to produce cold (~4 K) atoms
and molecules.

We are able to create high optical density (OD > 100) samples of ytterbium atoms for use in
nonlinear opticsexperiments: electromagnetically-induced transparency (EIT), stopped light,
and single-photon generation.Traditional EIT experiments using alkali atoms rely on coherence
between the light field and the atom'selectron spin. By using ground-state
Yb-173 (J=0, I=5/2) we can create and use coherence between thelight field and pure
nuclear spin states.

We also produce cold samples of atoms and molecules to study cold chemistry, with an
emphasis ontunneling-driven reactions and on using spin-symmetry to control reaction rates.