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

摘要

We demonstrate the control of He-4(2(3)S(1))-Li-7(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. nbsp;Published under an exclusive license by AIP Publishing.