Measuring a Photonic Qubit without Destroying It

作者：Geoff J. Pryde, Jeremy L. O’Brien, Andrew G. White, Stephen D. Bartlett, Timothy C. Ralph · 发表于：Physical Review Letters · 年份：2004 · DOI：10.1103/physrevlett.92.190402 · 被引用次数：129 · 研究领域：Quantum Information and Cryptography、Photonic and Optical Devices、Mechanical and Optical Resonators

Measuring the polarization of a single photon typically results in its destruction. We propose, demonstrate, and completely characterize a quantum nondemolition (QND) scheme for realizing such a measurement nondestructively. This scheme uses only linear optics and photodetection of ancillary modes to induce a strong nonlinearity at the single-photon level, nondeterministically. We vary this QND measurement continuously into the weak regime and use it to perform a nondestructive test of complementarity in quantum mechanics. Our scheme realizes the most advanced general measurement of a qubit to date: it is nondestructive, can be made in any basis, and with arbitrary strength.