A simple method for characterization of the magnetic field in an ion trap using Be+ ions

TL;DR

This paper presents a straightforward optical method using stimulated Raman spectroscopy with Be+ ions to determine and minimize magnetic fields in ion traps, enhancing precision in ion-based experiments.

Contribution

It introduces a simple, non-resonant optical technique for magnetic field characterization in ion traps, avoiding RF radiation and enabling precise magnetic field measurements.

Findings

Resolution of 0.04 G achieved.

Able to determine magnetic vector and field gradient.

Method applicable to precision spectroscopy of molecular ions.

Abstract

We demonstrate a simple method for the determination of the magnetic field in an ion trap using laser-cooled Be+ ions. The method is not based on magnetic resonance and thus does not require delivering radiofrequency (RF) radiation to the trap. Instead, stimulated Raman spectroscopy is used, and only an easily generated optical sideband of the laser cooling wave is required. The d.c. magnetic vector, averaged over the Be+ ion ensemble, is determined. Furthermore, the field strength can be minimized and an upper limit for the field gradient can be determined. The resolution of the method is 0.04 G at present. The relevance for precision rovibrational spectroscopy of molecular hydrogen ions is briefly discussed.