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

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.

Source: arXiv:2603.17955v1 - http://arxiv.org/abs/2603.17955v1 PDF: https://arxiv.org/pdf/2603.17955v1 Original Link: http://arxiv.org/abs/2603.17955v1