Field Locked to a Fock State by Quantum Feedback with Single Photon Corrections
X. Zhou, I. Dotsenko, Bruno Peaudecerf, T. Rybarczyk, C. Sayrin, S. Gleyzes, J. M. Raimond, M. Brune, S. Haroche · Physical Review Letters · 2012
Fock states with photon numbers n up to 7 are prepared on demand in a microwave superconducting cavity by a quantum feedback procedure that reverses decoherence-induced quantum jumps. Circular Rydberg atoms are used as quantum nondemolition sensors or as single-photon emitter or absorber actuators. The quantum nature of these actuators matches the correction of single-photon quantum jumps due to relaxation. The flexibility of this method is suited to the generation of arbitrary sequences of Fock states.