Sub-Recoil Transverse Momentum Width in a Cold Ytterbium Atomic Beam

TL;DR

This paper reports the creation of a slow ytterbium atomic beam with an exceptionally narrow transverse momentum width, enabling high-precision interferometry and advancing continuous angular rate measurements with cold alkaline-earth-like atoms.

Contribution

It introduces a novel momentum filtering technique using a metastable state to produce a narrow transverse momentum distribution in ytterbium beams.

Findings

Achieved a transverse momentum width of 0.44 times the photon recoil.

Generated a flux of approximately 6.7 million atoms per second.

Demonstrated efficient quasi-Bragg diffraction for interferometry.

Abstract

We demonstrate the generation of a slow ytterbium atomic beam with a transverse momentum width of $0.44(6)$ times the photon recoil associated with Bragg diffraction, and a flux of $6.7(9) \times 10^6$ atoms/s. This is achieved by applying momentum filtering through a long-lived metastable state to atoms prepared in a slow beam via two-dimensional transverse laser cooling. The resulting narrow momentum distribution enables efficient quasi-Bragg diffraction, which we exploit to realize a Bragg interferometer. These results mark a significant step toward continuous, high-precision, and magnetically insensitive angular rate measurements using cold alkaline-earth(-like) atomic beams.