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

Malo Cadoret (1) , Estefania de Mirandes (1) , Pierre Cladé (1) , Catherine Schwob (1) , François Nez (1) , Lucile Julien (1) , François Biraben (1) , Saïda Guellati-Khélifa (2)

1 LKB (Jussieu) - Laboratoire Kastler Brossel
2 LCM - Laboratoire commun de métrologie LNE-CNAM

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 $4.5 \times 10^{-9}$.

Domaines: Physique Atomique [physics.atom-ph]

Malo Cadoret, Estefania de Mirandes, Pierre Cladé, Catherine Schwob, François Nez, et al.. Determination of the fine structure constant with atom interferometry and Bloch oscillations. 2008. ⟨hal-00347833⟩