Entanglement-free heisenberg-limited phase estimation
Entanglement-free heisenberg-limited phase estimation
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DOI：
10.1038/nature06257
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发表时间：
2007-11-15
期刊：
影响因子：
64.8
通讯作者：
Pryde, G. J.
中科院分区：
文献类型：
--
作者：
Higgins, B. L.;Berry, D. W.;Pryde, G. J.
测量是所有定量科学的基础。一个关键的例子是光学相位的测量，用于长度计量和许多其他应用。精密测量的进步一直导致重要的科学发现。在基本水平上，测量精度受到所使用的量子资源（例如光子）的数量N的限制。标准的测量方案，独立使用每个资源，导致相位不确定性的比例为1/根N-称为标准量子极限。然而，长期以来，人们一直认为（1，2）应该可以达到仅受海森堡测不准原理限制的精度，从而将标度显著提高到1/N（参考文献3）。通常认为，实现这种改进需要使用奇异的量子纠缠态，例如NOON态（4，5）。这些状态极难产生。已经用N个光子或离子计数进行了测量方案。
Measurement underpins all quantitative science. A key example is the measurement of optical phase, used in length metrology and many other applications. Advances in precision measurement have consistently led to important scientific discoveries. At the fundamental level, measurement precision is limited by the number N of quantum resources (such as photons) that are used. Standard measurement schemes, using each resource independently, lead to a phase uncertainty that scales as 1/root N-known as the standard quantum limit. However, it has long been conjectured(1,2) that it should be possible to achieve a precision limited only by the Heisenberg uncertainty principle, dramatically improving the scaling to 1/N (ref. 3). It is commonly thought that achieving this improvement requires the use of exotic quantum entangled states, such as the NOON state(4,5). These states are extremely difficult to generate. Measurement schemes with counted photons or ions have been performed with N