Coherence Transfer in a Penning Ionizing Collision

Abstract

Modulation of the intensity of light emitted by ${\mathrm{Sr}}^{+}\left({}_{}{}^2{}_{}{}^{}P_{\frac{3}{2}}^{}{}_{}{}^{}\right)$ ions at the resonance frequency of metastable helium atoms has been observed, demonstrating that coherence has been transferred in the Penning collision. The coherent excitation of the Penning ions suggests that the techniques of "coherence spectroscopy" such as level-crossing and Hanle experiments can be extended to excited states of Penning ions which are currently inaccessible by means of optical excitation.