We demonstrate that the contextuality of measurement selection can enhance the precision of quantum metrology with a simple linear optical experiment. Contextuality is a nonclassical property known as a resource for various quantum information processing tasks. Recent studies show that contextuality by anomalous weak values can be utilized to enhance metrological precision, unraveling the role of contextuality in quantum metrology. Our contextual quantum metrology (coQM) scheme can elevate the precision of the optical polarimetry as much as 6 times the precision limit given by the Quantum Fisher Information. We achieve the contextuality-enabled enhancement with two mutually complementary measurements, whereas, in the conventional method, some optimal measurements to achieve the precision limit are either theoretically challenging to find or experimentally infeasible to realize. These results highlight that the contextuality of measurement selection is applicable in practice for quantum metrology.

我们证明，测量选择的上下文可以通过简单的线性光学实验来提高量子计量的精度。上下文性是一种非经典属性，被称为各种量子信息处理任务的资源。最近的研究表明，异常弱值的关联性可用于提高计量精度，揭示关联性在量子计量中的作用。我们的上下文量子计量 (coQM) 方案可以将光学偏振测量的精度提高至 Quantum Fisher Information 给出的精度限制的 6 倍。我们通过两个相互补充的测量来实现上下文增强，而在传统方法中，一些达到精度限制的最佳测量要么在理论上难以找到，要么在实验上无法实现。这些结果强调测量选择的背景适用于量子计量的实践。