Spin-state-controlled chemi-ionization reactions between metastable helium atoms and ground-state lithium atoms

Abstract

We demonstrate the control of ${}^4$He(2${}^3$S${}_1$)-${}^7$Li(2${}^2$S${}_{1/2}$) chemi-ionization reactions by all-optical electron-spin-state preparation of both atomic species prior to the collision process. Our results demonstrate that chemi-ionization is strongly suppressed (enhanced) for non-spin-conserving (spin-conserving) collisions at thermal energies. These findings are in good agreement with a model based on spin angular momentum coupling of the prepared atomic states to the quasi-molecular states. Small deviations from the model indicate the contribution of the ${}^4{\Sigma }^{+}$ channel to the reaction rate which is in violation of spin conservation.

References in corpus (10)

• Ultracold dense samples of dipolar RbCs molecules in the rovibrational and hyperfine ground state
• Ultracold Dipolar Gas of Fermionic ${}^{23}$Na${}^{40}$K Molecules in their Absolute Ground State
• Creation of ultracold ${}^{87}$RbCs molecules in the rovibrational ground state
• Observation of Quantum Effects in sub Kelvin Cold Reactions
• A Degenerate Bose-Fermi Mixture of Metastable Atoms
• Observation of orbiting resonances in He(3S1) + NH3 Penning ionization
• Energy dependent stereodynamics of the Ne(${}^3$P${}_2$)+Ar reaction
• Ultracold mixtures of metastable He and Rb: scattering lengths from ab initio calculations and thermalization measurements
• Quantum-State Controlled Penning Ionization Reactions between Ultracold Alkali and Metastable Helium Atoms
• Preparation of individual magnetic sub-levels of ${}^4$He($2^3$S${}_1$) in a supersonic beam using laser optical pumping and magnetic hexapole focusing