Abstract
In quantum metrology, the parameter estimation accuracy is bounded by quantum Fisher information. In this paper we present coherence measures in terms of (quantum) Fisher information by directly considering the postselective nonunitary parametrization process. This coherence measure demonstrates the apparent operational meaning by the exact connection between coherence and parameter estimation accuracy. We also discuss the distinction between our coherence measure and the quantum Fisher information subject to unitary parametrization. The analytic coherence measure is given for qubit states.
- Received 26 June 2022
- Revised 16 September 2022
- Accepted 15 November 2022
DOI:https://doi.org/10.1103/PhysRevA.106.052432
©2022 American Physical Society
Physics Subject Headings (PhySH)
Quantum Information, Science & Technology