Pezzé L, Smerzi A, Khoury G, Hodelin J F, Bouwmeester D
BEC-CNR-INFM and Dipartimento di Fisica, Università di Trento, I-38050 Povo, Italy.
Phys Rev Lett. 2007 Nov 30;99(22):223602. doi: 10.1103/PhysRevLett.99.223602. Epub 2007 Nov 27.
We study a Mach-Zehnder interferometer fed by a coherent state in one input port and vacuum in the other. We explore a Bayesian phase estimation strategy to demonstrate that it is possible to achieve the standard quantum limit independently from the true value of the phase shift and specific assumptions on the noise of the interferometer. We have been able to implement the protocol by using parallel operation of two photon-number-resolving detectors and multiphoton coincidence logic electronics at the output ports of a weakly illuminated Mach-Zehnder interferometer. This protocol is unbiased, saturates the Cramer-Rao phase uncertainty bound, and, therefore, is an optimal phase estimation strategy.
我们研究了一种马赫-曾德尔干涉仪，其一个输入端口注入相干态，另一个输入端口注入真空态。我们探索了一种贝叶斯相位估计策略，以证明可以独立于相移的真实值以及干涉仪噪声的特定假设来达到标准量子极限。我们通过在弱光马赫-曾德尔干涉仪的输出端口使用两个光子数分辨探测器的并行操作和多光子符合逻辑电子学，成功实现了该协议。此协议是无偏的，达到了克拉美-罗相位不确定度界限，因此是一种最优的相位估计策略。
