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arXiv · 2103.14365

Analysis of nonresonant effects in the two-photon spectroscopy of helium

T. Zalialiutdinov·A. Anikin·D. Solovyev
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Abstract

In the present paper, we study nonresonant corrections for experimental measurements of the transition frequencies in the helium atom. Having attracted more attention, such effects can make a significant contribution to experiments based on one- and two-photon atomic spectroscopy. The quantum interference effects in the measurements of $2^3S_1-n^3D_1$ ($ n=3,\,4,\,5 $) transition frequencies based on Doppler-free two-photon spectroscopy, are considered as a possible source of current discrepancy between the experimental and theoretical data. We demonstrate that line profile asymmetry caused by the quantum interference of fine sub-levels of the $ ^3D_{J} $ $ (J=1,2,3) $ state can reach tenths of a megahertz for different experimental conditions. Thus, previously unaccounted nonresonant corrections should be taken in next-generation experimental measurements of transitions frequencies in helium. However, they could not completely eliminate the current imbalance in the study of helium spectra and the question is still open.

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T. Zalialiutdinov, A. Anikin, D. Solovyev. 2021-03-26. Analysis of nonresonant effects in the two-photon spectroscopy of helium. https://doi.org/10.1088/1361-6455/ac232c

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