Proof of principle for a high sensitivity search for the electric dipole moment of the electron using the metastable a(1)[^3\Sigma^+] state of PbO

TL;DR

This paper demonstrates experimental techniques with high sensitivity for measuring Zeeman and Stark effects in PbO's metastable state, paving the way for a more sensitive search for the electron's electric dipole moment.

Contribution

The development of experimental methods enabling high-sensitivity Zeeman and Stark effect measurements in PbO's metastable state for electron EDM searches.

Findings

Observation of Zeeman quantum beats with shot-noise limited extraction

High counting rates and long coherence times achieved

Potential to improve electron EDM sensitivity by over two orders of magnitude

Abstract

The metastable a(1)[^3\Sigma^+] state of PbO has been suggested as a suitable system in which to search for the electric dipole moment (EDM) of the electron. We report here the development of experimental techniques allowing high-sensitivity measurements of Zeeman and Stark effects in this system, similar to those required for an EDM search. We observe Zeeman quantum beats in fluorescence from a vapor cell, with shot-noise limited extraction of the quantum beat frequencies, high counting rates, and long coherence times. We argue that improvement in sensitvity to the electron EDM by at least two orders of magnitude appears possible using these techniques.