Doppler- and recoil-free laser excitation of Rydberg states via three-photon transitions

TL;DR

This paper presents a three-photon laser excitation scheme for Rydberg states that eliminates recoil and Doppler effects, resulting in narrower spectral lines and longer coherence times, enhancing quantum gate fidelity and spectroscopic precision.

Contribution

The paper introduces a novel three-photon excitation method with a star-like geometry that reduces Doppler and recoil effects in Rydberg atom excitation.

Findings

Narrower spectral lines compared to one- and two-photon methods.

Longer coherence times in both cold and hot Rb vapors.

Potential improvements in quantum gate fidelity and spectroscopic accuracy.

Abstract

Three-photon laser excitation of Rydberg states by three different laser beams can be arranged in a star-like geometry that simultaneously eliminates the recoil effect and Doppler broadening. Our analytical and numerical calculations for a particular laser excitation scheme 5S_{1/2}->5P_{3/2}->6S_{1/2}->nP in Rb atoms have shown that compared to the one- and two-photon laser excitation this approach provides much narrower line width and longer coherence time for both cold atom samples and hot vapors, if the intermediate one-photon resonances of the three-photon transition are detuned by more than respective single-photon Doppler widths. This method can be used to improve fidelity of Rydberg quantum gates and precision of spectroscopic measurements in Rydberg atoms.