Direct Measurement of the Wigner Function of a One-Photon Fock State in a Cavity
Patrice Bertet, Alexia Auffèves, Paolo Maioli, S. Osnaghi, Tristan Meunier, M. Brune, J. M. Raimond, S. Haroche · Physical Review Letters · 2002
We have measured the complete Wigner function W of the vacuum and of a single-photon state for a field stored in a high-Q cavity. This experiment implements the direct Lutterbach and Davidovich method [L. G. Lutterbach and L. Davidovich, Phys. Rev. Lett. 78, 2547 (1997)]] and is based on the dispersive interaction of a single circular Rydberg atom with the cavity field. The nonclassical nature of the single-photon field is exhibited by a region of negative W values. Extensions to other nonclassical cavity field states are discussed.