Incompatibility measures in multi-parameter quantum estimation under
hierarchical quantum measurements
- URL: http://arxiv.org/abs/2109.05807v3
- Date: Mon, 27 Jun 2022 08:04:16 GMT
- Title: Incompatibility measures in multi-parameter quantum estimation under
hierarchical quantum measurements
- Authors: Hongzhen Chen, Yu Chen, Haidong Yuan
- Abstract summary: We show an approach to study the incompatibility under general $p$-local measurements.
We demonstrate the power of the approach by presenting a hierarchy of analytical bounds on the tradeoff.
- Score: 4.980960723762946
- License: http://creativecommons.org/licenses/by/4.0/
- Abstract: The incompatibility of the measurements constraints the achievable precisions
in multi-parameter quantum estimation. Understanding the tradeoff induced by
such incompatibility is a central topic in quantum metrology. Here we provide
an approach to study the incompatibility under general $p$-local measurements,
which are the measurements that can be performed collectively on at most $p$
copies of quantum states. We demonstrate the power of the approach by
presenting a hierarchy of analytical bounds on the tradeoff among the precision
limits of different parameters. These bounds lead to a necessary condition for
the saturation of the quantum Cram\'er-Rao bound under $p$-local measurements,
which recovers the partial commutative condition at p=1 and the weak
commutative condition at $p=\infty$. As a further demonstration of the power of
the framework, we present another set of tradeoff relations with the right
logarithmic operators(RLD).
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