Precision measurement of the branching fractions of the 4P3/2 decay of Ca II

TL;DR

This paper reports highly precise measurements of the decay branching ratios of the 4P3/2 level in a single calcium ion, significantly improving the accuracy over previous results using a novel population transfer monitoring technique.

Contribution

The study introduces a new method for measuring branching ratios in trapped ions, achieving forty times better accuracy than prior measurements.

Findings

Branching fractions into 4S1/2, 3D5/2, 3D3/2 levels are 0.9347, 0.0587, 0.00661 respectively.

The ratio A(P3/2-S1/2)/sum of A(P3/2-D_J) is 14.31, with a forty-fold accuracy improvement.

High precision achieved by monitoring population transfer during repeated pumping.

Abstract

We perform precision measurements of the branching ratios of the 4P3/2 level decay of a single 40Ca+ ion suspended in a linear Paul trap. High precision is achieved by a novel technique based on monitoring the population transfer when repeatedly pumping the ion between different internal states. The branching fractions into the 4S1/2, 3D5/2 and 3D3/2 levels are found to be 0.9347(3), 0.0587(2) and 0.00661(4), respectively. For the branching ratio A(P3/2-S1/2)/\sum_J A(P3/2-D_J)=14.31(5), we find a forty-fold improvement in accuracy as compared to the best previous measurement.