Approaching the ultimate limit of quantum multiparameter estimation by many-body physics

TL;DR

This paper proposes a physical measurement scheme involving many-body physics and ancilla interactions to approach the ultimate precision limit in quantum multiparameter estimation, providing a concrete experimental setup.

Contribution

It introduces a practical measurement scheme that uses bosonic ancillas and general-dyne detection to nearly reach the Holevo--Nagaoka bound in quantum multiparameter estimation.

Findings

Scheme approaches the Holevo--Nagaoka bound

Provides a concrete experimental setup

Enhances precision in quantum multiparameter estimation

Abstract

I propose a physical measurement scheme on multiple independent and identically distributed quantum objects to approach the Holevo--Nagaoka bound for quantum multiparameter estimation. The scheme entails a physical interaction of the objects with bosonic ancillas, followed by a general-dyne measurement of the ancillas. The proposal offers a more concrete description of the experimental setup needed to achieve the ultimate precision limit set by the bound.