QUANTUM NON-DEMOLITION COUNTINGOF PHOTONS IN A CAVITY

摘要

The photons of a microwave field stored in a high-Q cavity are detected non-destructively by a beam of circular Rydberg atoms crossing the cavity oneby one. The field collapses into a Fock state as information is progressivelyextracted by the atoms. The photon number subsequently decays through asuccession of quantum jumps under the effect of cavity damping. The QNDdetection of photons could be used for the preparation and study of variouskinds of non-classical fields localized in one or two cavities.