Characterising a tunable, pulsed atomic beam using matter-wave interferometry

TL;DR

This paper presents the creation and detailed characterization of a tunable, spin-polarized atomic beam of metastable argon, using matter-wave interferometry to measure velocity, velocity spread, Van der Waals interactions, and spin polarization.

Contribution

It introduces a method to precisely characterize a tunable atomic beam, including velocity, interactions, and spin polarization, with novel application of matter-wave interferometry.

Findings

Beam velocity determined with <1% precision

Van der Waals coefficient measured as 1.84±0.17 a.u.

Achieved 96% spin polarization in the beam

Abstract

We describe the creation and characterisation of a velocity tunable, spin-polarized beam of slow metastable argon atoms. We show that beam velocity can be determined with a precision below 1 \% using matter-wave interferometry. The profile of the interference pattern was also used to determine the velocity spread of the beam, as well as Van der Waals co-efficient for the interaction between the metastable atoms and the multi-slit silicon nitride grating. The Van der Waals co-efficient was determined to be $C_3$=1.84$\pm$0.17\,a.u., in good agreement with values derived from spectroscopic data. Finally, the spin polarization of the beam produced during acceleration of the beam was also measured, demonstrating a spatially uniform spin polarization of 96 \% in the m=+2 state.