Quantum-nondemolition measurement of photon arrival using an atom-cavity system
Kunihiro Kojima, Akihisa Tomita · Physical Review A · 2007
A simple and efficient quantum-nondemolition measurement (QND) scheme is proposed in which the arrival of a signal photon is detected without affecting the qubit state. The proposed QND scheme functions even if the ancillary photon is replaced with weak light composed of vacuum and one-photon states. Although the detection scheme is designed for entanglement sharing applications, it is also suitable for general purification of a single-photon state.