Relaxation of Cs atomic polarization at surface coatings characterized by X-ray photoelectron spectroscopy

TL;DR

This study investigates how surface coatings like paraffin and DLC affect cesium vapor spin relaxation, revealing that coating quality and coverage are crucial for anti-relaxation performance, with paraffin coatings showing some effectiveness.

Contribution

It provides detailed surface composition analysis of paraffin coatings via XPS and links coating imperfections to spin relaxation effectiveness, offering insights into surface preparation for atomic polarization.

Findings

High paraffin and low Cs coverage improve anti-spin relaxation.

Surface imperfections in coatings correlate with reduced effectiveness.

DLC films did not demonstrate expected anti-relaxation effects.

Abstract

Paraffin coatings on glass slides were investigated through both X-ray photoelectron spectroscopy (XPS) and spin relaxation measurement for cesium (Cs) vapor. The components of the glass substrate, such as silicon (Si) and oxygen (O), existed in the XPS spectra of the coated slides, indicating the imperfection of the prepared paraffin coatings. The substrate was not observed after the annealing of the coatings in Cs vapor, which is known as a `ripening' process for spin relaxation measurement. We found a general trend that effective anti-spin relaxation performance requires high paraffin and low Cs coverage on the surface. We also examined a type of diamond-like carbon (DLC) film, anticipating the effect of anti-spin relaxation; our attempts have failed to date.