One from many: estimating a function of many parameters. (26th November 2020)

• Record Type: Journal Article
• Authors: Gross, Jonathan A; Caves, Carlton M
• Is Part Of: Journal of physics. Volume 54:Number 1(2021)
• Publication Date: 2020-11-26
• Subjects: quantum metrology -- multi-parameter estimation -- Fisher information -- Cramer–Rao bound -- process norm; Mathematical physics -- Periodicals; Statistical physics -- Periodicals; Quantum theory -- Periodicals; Matter -- Properties -- Periodicals; 530.105
• DOI: 10.1088/1751-8121/abb9ed
• Languages: English
• ISSNs: 1751-8113

Abstract

Abstract: Difficult it is to formulate achievable sensitivity bounds for quantum multiparameter estimation. Consider a special case, one parameter from many: many parameters of a process are unknown; estimate a specific linear combination of these parameters without having the ability to control any of the parameters. Superficially similar to single-parameter estimation, the problem retains genuinely multiparameter aspects. Geometric reasoning demonstrates the conditions, necessary and sufficient, for saturating the fundamental and attainable quantum-process bound in this context.