Precision Measurement of Transition Matrix Elements via Light Shift Cancellation

TL;DR

This paper introduces a precise method for measuring atomic transition matrix elements by analyzing light shifts near zero-shift wavelengths, achieving high accuracy and first measurements for rubidium's 5s-6p transitions.

Contribution

The authors develop a novel technique using light shift cancellation to measure atomic matrix elements with unprecedented precision, including the first measurement of rubidium's 5s-6p matrix elements.

Findings

Achieved 10^{-3} level accuracy in matrix element measurements.

First measurement of rubidium's 5s-6p matrix elements.

Results are an order of magnitude more accurate than previous theoretical values.

Abstract

We present a method for accurate determination of atomic transition matrix elements at the 10^{-3} level. Measurements of the ac Stark (light) shift around "magic-zero" wavelengths, where the light shift vanishes, provide precise constraints on the matrix elements. We make the first measurement of the 5s-6p matrix elements in rubidium by measuring the light shift around the 421 nm and 423 nm zeros with a sequence of standing wave pulses. In conjunction with existing theoretical and experimental data, we find 0.3236(9) e a_0 and 0.5230(8) e a_0 for the 5s-6p_{1/2} and 5s-6p_{3/2} elements, respectively, an order of magnitude more accurate than the best theoretical values. This technique can provide needed, accurate matrix elements for many atoms, including those used in atomic clocks, tests of fundamental symmetries, and quantum information.