Combination of Bloch oscillations with a Ramsey-Bord\'e interferometer : new determination of the fine structure constant

TL;DR

This paper introduces a novel experimental method combining atom interferometry and Bloch oscillations to measure the fine structure constant with unprecedented precision, providing a stringent test of quantum electrodynamics.

Contribution

The paper presents a new experimental scheme that enhances recoil velocity measurement accuracy, leading to a highly precise determination of the fine structure constant.

Findings

Measured the ratio h/m_Rb with improved accuracy

Derived a new value for the fine structure constant with low uncertainty

Provided the most stringent test of QED to date

Abstract

We report a new experimental scheme which combines atom interferometry with Bloch oscillations to provide a new measurement of the ratio $h/m_{\mathrm{Rb}}$. By using Bloch oscillations, we impart to the atoms up to 1600 recoil momenta and thus we improve the accuracy on the recoil velocity measurement. The deduced value of $h/m_{\mathrm{Rb}}$ leads to a new determination of the fine structure constant $\alpha^{-1}=137.035 999 45 (62)$ with a relative uncertainty of $4.6\times 10^{-9}$. The comparison of this result with the value deduced from the measurement of the electron anomaly provides the most stringent test of QED.