Comment on "Measuring the enhancement factor of the hyperpolarized Xe in nuclear magnetic resonance gyroscopes"

TL;DR

This paper critically examines a recent claim of a significantly higher enhancement factor in Cs-$^{129}$Xe SEOP, highlighting inconsistencies and lack of detailed methodology that cast doubt on the original findings.

Contribution

The authors provide a critical commentary questioning the validity of the reported enhancement factor measurement and emphasize the need for clearer experimental details.

Findings

The reported enhancement factor is likely inaccurate due to mischaracterization.

The original experimental methodology lacks sufficient detail for validation.

The discrepancy calls for further rigorous investigation.

Abstract

Z. Xu, et al. [Phys. Rev. A 103, 023114 (2021)], have reported a measurement for the enhancement factor $\kappa$, which characterizes the overlap of the electron wavefunction with the noble-gas nucleus in Cs-$^{129}$Xe spin-exchange optical pumping (SEOP), that is more than an order of magnitude higher than previous experimental results and theoretical estimates. There is no plausible proposed physical basis for this discrepancy. As the authors repeatedly mischaracterize the nature and properties of the enhancement factor and do not completely describe their experimental technique, there is little reason to accept or consider this result in its current form in the context of future relevant work on Cs-Xe SEOP and its applications.