Nonlinear Zeeman effect in photoassociation spectra of $^{40}$Ca near the $^3$P$_1$+$^1$S$_0$ asymptote

TL;DR

This paper models the nonlinear Zeeman effect in calcium photoassociation spectra near a specific asymptote, revealing significant shifts at low magnetic fields and refining molecular dispersion coefficients.

Contribution

It introduces a coupled-channel model to accurately predict nonlinear Zeeman effects and corrects previous measurements of molecular dispersion coefficients.

Findings

Nonlinear Zeeman shifts reach several kHz at a few mT.

The coupled-channel model accurately reproduces experimental spectra.

Corrected dispersion coefficients for specific molecular states.

Abstract

We present calculations of the Zeeman effect of narrow photoassociation lines of $^{40}$Ca near the $^3$P$_1$ + $^1$S$_0$ asymptote. Using a coupled-channel model we find a nonlinear Zeeman effect that even at low fields of a few mT amounts to several kHz. With this model we analyze previous measurements and give corrected long range dispersion coefficients of the $^3\Pi_{u}$ and $^3\Sigma^+ _{u}$ states.