Laser Field Interactions with Atoms and Molecules

Man Mohan

A. C. Brown, Gabriel G. Balint‐Kurti, OS Vasyutinskii

André D. Bandrauk

Sergey Alyabyshev, Timur V. Tscherbul, Roman V. Krems

We present a rigorous study of low-temperature collisions of polar molecules and atoms in a microwave laser field. Our calculations show that inelastic relaxation of molecules in a microwave cavity may occur through collision-induced absorption of photons stimulated by the anisotropy of the atom-molecule interaction potential. Our results indicate that molecular collisions at temperatures below 1 K can be efficiently manipulated with microwave laser fields of moderate strength.

Sergey Alyabyshev, Roman V. Krems

We explore the effects of microwave laser fields on spin-changing transitions in collisions of polar molecules in a $^{2}\ensuremath{\Sigma}$ electronic state with atoms in the presence of a static magnetic field. We use the dressed-state formalism of quantum optics to describe the interaction of the radiation field with the collision complex and perform rigorous scattering calculations to study spin-changing transitions in collisions of CaH molecules with He atoms at temperatures below 1 K. Our calculations demonstrate that collision-induced spin relaxation of $^{2}\ensuremath{\Sigma}$ molecules is enhanced near avoided crossings between different Zeeman levels. We show that the positions of the avoided crossings can be modified by varying the frequency and the intensity of the microwave laser field and discuss the mechanisms of microwave field control of spin-dependent interactions in cold open-shell molecules.

Chong Ye, Libin Fu, Jie Liu

Abstract We propose a theoretical scheme to separate a molecular cloud from atoms in analogy to the spin Hall effect and to completely transfer Feshbach molecules to the ground state by applying a spatially modulated laser field to an atom–molecule mixed gas. In particular, the laser–molecule interaction induces a synthetic U (1) gauge potential for the dressed molecular dark state. Through numerical simulation, we demonstrate that such a gauge field leads to a spin Hall separation of atoms and molecules. In such a process, molecules can be transformed into the ground state completely.