# Isotope shift of nuclear magnetic resonances in 129Xe and 131Xe caused by spin-exchange pumping by alkali metal atoms

**Authors:** V.I. Petrov, A.S. Pazgalev, and A.K. Vershovskii

arXiv: 1906.06556 · 2026-04-28

## TL;DR

This study investigates the isotope shifts in NMR frequencies of xenon isotopes 129Xe and 131Xe polarized by alkali metal atoms, revealing that inhomogeneous magnetic fields significantly influence the shifts.

## Contribution

The paper presents a numerical model explaining the isotope shift in xenon NMR frequencies, aligning well with experimental data and highlighting the role of local magnetic field averaging.

## Key findings

- Isotope shift is mainly due to incomplete averaging of inhomogeneous magnetic fields.
- The numerical model qualitatively and quantitatively matches experimental results.
- Inhomogeneous magnetic fields significantly affect NMR frequency shifts in xenon isotopes.

## Abstract

The effect of isotope shifts of nuclear magnetic resonance (NMR) frequency in xenon isotopes 129Xe and 131Xe polarized by optically-oriented alkali metal atoms is not only of fundamental interest, but also of practical significance since it is the main factor limiting the accuracy of a whole class of prospective navigation and metrological devices. We have studied the parametric dependences of the isotope shift and have shown that this effect is largely due to incomplete averaging of a inhomogeneous local magnetic field by two xenon isotopes. A numerical model has been derived, which qualitatively describes the effect of isotope frequency shift and provides a good quantitative agreement with the experiment.

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Source: https://tomesphere.com/paper/1906.06556