Precision measurement of the ground-state hyperfine constant for $^9Be^+$ in a linear Paul trap via magnetically insensitive hyperfine transitions

TL;DR

This paper reports a highly precise measurement of the hyperfine constant for $^9Be^+$ ions using magnetically insensitive transitions in a linear Paul trap, achieving a relative precision of 5.6×10⁻⁸.

Contribution

It presents the first high-precision measurement of the ground-state hyperfine constant for $^9Be^+$ using magnetically insensitive transitions in a linear Paul trap.

Findings

Hyperfine constant A = -625.008840(35) MHz with high precision

Measured transition frequencies over a magnetic field range of ±0.5 mT

Data fitted considering high-order Zeeman effects

Abstract

Direct measurements of the ground-state magnetically insensitive hyperfine transition |F=2,mF=0>->|F=1,mF=0> of $^9Be^+$ ions have been performed using microwave-driven state transfer. The $^9Be^+$ ions are confined and laser-cooled in a linear Paul trap, forming a Coulomb crystal. The transition frequencies have been measured over a magnetic field range of $ \pm 0.5 mT $ centered at zero magnetic field, and the acquired data were fitted accounting for the high-order Zeeman effect. The hyperfine constant A is determined to be -625.008840(35) MHz, achieving a relative precision of $ 5.6 \times 10^{-8}$.