Quantum nondemolition measurement of small photon numbers by Rydberg-atom phase-sensitive detection

作者：M. Brune, S. Haroche, Victor Lefèvre, J. M. Raimond, Nicim Zagury · 发表于：Physical Review Letters · 年份：1990 · DOI：10.1103/physrevlett.65.976 · 被引用次数：506 · 研究领域：Quantum Information and Cryptography、Quantum Mechanics and Applications、Cold Atom Physics and Bose-Einstein Condensates

We describe a new quantum nondemolition method to monitor the number N of photons in a microwave cavity. We propose coupling the field to a quasiresonant beam of Rydberg atoms and measuring the resulting phase shift of the atom wave function by the Ramsey separated-oscillatory-fields technique. The detection of a sequence of atoms reduces the field into a Fock state. With realistic Rydberg atom-cavity systems, small-photon-number states down to N=0 could be prepared and continuously monitored.