Hyperfine interaction in the Autler-Townes effect II: control of two-photon selection rules in the Morris-Shore basis

Abstract

We investigated the absence of certain bright peaks in Autler-Townes laser excitation spectra of alkali metal atoms. Our research revealed that these dips in the spectra are caused by a specific architecture of adiabatic (or ``laser-dressed'') states in hyperfine (HF) components. The dressed states' analysis pinpointed several cases where constructive and destructive interference between HF excitation pathways in a two-photon excitation scheme limits the available two-photon transitions. This results in a reduction of the conventional two-photon selection rule for the total angular momentum $F$, from $\Delta F=0,\pm 1$ to $\Delta F\equiv 0$. Our discovery presents practical methods for selectively controlling the populations of unresolvable HF $F$-components of $n{s}_{1/2}$ Rydberg states in alkali metal atoms. Using numerical simulations with sodium and rubidium atoms, we demonstrate that by blocking the effects of HF interaction with a specially tuned auxiliary control laser field, the deviations from the ideal selectivity of the HF components population can be lower than $0.01\%$ for Na and $0.001\%$ for Rb atoms.

20 pages, 14 figures, to be submitted to PRA. Changelog: * added missing ORCID iDs; * Notation used in figures 4,6 is now consistent with the rest of the manuscript: Pump paser -> S-laser; * corrected typos, more precise language througout the paper; * improved legibility of labels in figures 4-8