# Dipolar and scalar $^{3}$He-$^{129}$Xe frequency shifts in stemless cells

## TL;DR

This study investigates how cell shape affects nuclear spin frequency shifts in a $^{3}$He-$^{129}$Xe comagnetometer, identifying an optimal aspect ratio to cancel dipolar effects and measuring a scalar collisional frequency shift consistent with theory.

## Contribution

It demonstrates how to control dipolar frequency shifts via cell geometry and accurately measures the scalar $^{3}$He-$^{129}$Xe collisional frequency shift.

## Key findings

- Optimal aspect ratio cancels dipolar effects in cylindrical cells.
- Measured scalar collisional frequency shift with enhancement factor $oxed{-0.011 extpm0.001}$.
- Results agree with theoretical predictions.

## Abstract

We study nuclear spin frequency shifts in a $^{3}$He-$^{129}$Xe comagnetometer caused by spin polarization of $^{3}$He. We use stemless cylindrical cells to systematically vary the cell geometry and separately measure the cell shape-dependent and shape-independent frequency shifts. We find that a certain aspect ratio for a cylindrical cell cancels the dipolar effects of $^3$He magnetization in the regime of fast spin diffusion. Using this control we observe a scalar $^{3}$He-$^{129}$Xe collisional frequency shift characterized by an enhancement factor $\kappa_{\text{HeXe}} = -0.011\pm0.001$ in excellent agreement with theoretical calculation.