Combination of BLOCH oscillations with a Ramsey-Bordé interferometer: new determination of the fine structure constant

Phys Rev Lett. 2008 Dec 5;101(23):230801. doi: 10.1103/PhysRevLett.101.230801. Epub 2008 Dec 3.

Abstract

We report a new experimental scheme which combines atom interferometry with Bloch oscillations to provide a new measurement of the ratio h/mRb. 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/mRb leads to a new determination of the fine structure constant alpha(-1) =137.03599945 (62) with a relative uncertainty of 4.6 x 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.