Measurement noise susceptibility in quantum estimation

TL;DR

This paper introduces a new measure called Fisher Information Measurement Noise Susceptibility to evaluate how measurement imperfections can reduce the precision of quantum parameter estimation, with applications in interferometry and optical imaging.

Contribution

It proposes a novel concept and explicit formula to quantify the robustness of quantum estimation schemes against measurement noise, addressing a gap in existing quantum metrology tools.

Findings

Fisher Information Measurement Noise Susceptibility effectively quantifies robustness.

Application to quantum interferometry shows significant insights.

Useful in analyzing super-resolution optical imaging schemes.

Abstract

Fisher Information is a key notion in the whole field of quantum metrology. It allows for a direct quantification of maximal achievable precision of estimation of parameters encoded in quantum states using the most general quantum measurement. It fails, however, to quantify the robustness of quantum estimation schemes against measurement imperfections, which are always present in any practical implementations. Here, we introduce a new concept of Fisher Information Measurement Noise Susceptibility that quantifies the potential loss of Fisher Information due to small measurement disturbance. We derive an explicit formula for the quantity, and demonstrate its usefulness in analysis of paradigmatic quantum estimation schemes, including interferometry and super-resolution optical imaging.