Improving sensitivity to magnetic fields and electric dipole moments by using measurements of individual magnetic sublevels

TL;DR

This paper proposes using measurements of individual magnetic sublevels to enhance the sensitivity of atomic magnetic field and electric dipole moment measurements, reducing noise and mitigating systematic shifts.

Contribution

It introduces a method to improve measurement sensitivity by analyzing populations of magnetic sublevels, including strategies to counteract systematic shifts.

Findings

Measurement sensitivity is improved by a factor of 1/√(2F(F+1)) when using m=0 sublevel initialization.

Combining populations in even or odd sublevels makes measurements independent of certain systematic shifts.

Optimal sensitivity is achievable with superposition states when tensor Stark shift dominates over transverse magnetic fields.

Abstract

We explore ways to use the ability to measure the populations of individual magnetic sublevels to improve the sensitivity of magnetic field measurements and measurements of atomic electric dipole moments (EDMs). When atoms are initialized in the $m=0$ magnetic sublevel, the shot-noise-limited uncertainty of these measurements is $1/\sqrt{2F(F+1)}$ smaller than that of a Larmor precession measurement. When the populations in the even (or odd) magnetic sublevels are combined, we show that these measurements are independent of the tensor Stark shift and the second order Zeeman shift. We discuss the complicating effect of a transverse magnetic field and show that when the ratio of the tensor Stark shift to the transverse magnetic field is sufficiently large, an EDM measurement with atoms initialized in the superposition of the stretched states can reach the optimal sensitivity.