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 $α$ . The velocity variation due to Bloch oscillations is measured using atom interferometry. This method yields to a value of the fine structure constant $α^{-1}= 137.035 999 45 (62)$ with a relative uncertainty of about $4.5 \times 10^{-9}$ .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 $α$. The velocity variation due to Bloch oscillations is measured using atom interferometry. This method yields to a value of the fine structure constant $α^{-1}= 137.035 999 45 (62)$ with a relative uncertainty of about $4.5 \times 10^{-9}$.

arXiv:0812.3139International Conference on Atomic Physics (ICAP)Mar 1, 20090 citations

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

α

. The velocity variation due to Bloch oscillations is measured using atom interferometry. This method yields to a value of the fine structure constant

α^{-1}= 137.035 999 45 (62)

with a relative uncertainty of about

4.5 \times 10^{-9}