Type: Article
Publication Date: 2009-10-07
Citations: 82
DOI: https://doi.org/10.1103/physrevlett.103.153601
We report on a direct measurement of a phase shift on a weak coherent beam by a single 87Rb atom in a Mach-Zehnder interferometer. By strongly focusing the probe mode to the location of the atom, a maximum phase shift of about 1 degree is observed experimentally.