Determination of the fine structure constant with atom interferometry and Bloch oscillations

TL;DR

This paper presents a precise measurement of the fine structure constant using atom interferometry combined with Bloch oscillations to transfer photon momentum to atoms, achieving high accuracy in fundamental constant determination.

Contribution

The study introduces a novel method combining Bloch oscillations with atom interferometry to measure the fine structure constant with unprecedented precision.

Findings

Measured the fine structure constant as α⁻¹=137.03599945(62)

Achieved a relative uncertainty of about 4.5×10⁻⁹

Demonstrated high-precision recoil velocity measurement

Abstract

We use Bloch oscillations to transfer coherently many photon momenta to atoms. Then we can measure accurately the recoil velocity $\hbar k/m$ and deduce the fine structure constant $\alpha$. The velocity variation due to Bloch oscillations is measured using atom interferometry. This method yields to a value of the fine structure constant $\alpha^{-1}= 137.035 999 45 (62)$ with a relative uncertainty of about $4.5 \times 10^{-9}$.