Excitation of E1-forbidden atomic transitions with electric, magnetic, or mixed multipolarity in light fields carrying orbital and spin angular momentum [Invited]

摘要

Photons carrying a well-defined orbital angular momentum have been proven to modify spectroscopic selection rules in atomic matter. Excitation profiles of electric quadrupole transitions have been measured with single trapped Ca-40(+) ions for varying polarizations. We further develop the photo-absorption formalism to study the case of arbitrary alignment of the beam's optical axis with respect to the ion's quantization axis and mixed multipolarity. Thus, predictions for MI-dominated Ar-40(13+), E3-driven Yb-171(+) and Yb-172(+), and B-like Ne-20(5+) are presented. The latter case displays novel effects, coming from the presence of a strong photon-magnetic dipole coupling. (C) 2019 Optical Society of America