An optimal measurement strategy to beat the quantum uncertainty in correlated system

TL;DR

This paper introduces a practical measurement strategy leveraging entanglement to reduce quantum uncertainty in bipartite systems, leading to new uncertainty relations and applications in quantum nonlocality detection.

Contribution

It proposes a novel method to lower measurement uncertainty using entanglement and constructs a family of conditional majorization uncertainty relations applicable to multiple observables.

Findings

Reduced local measurement uncertainty demonstrated

New uncertainty relations reveal complex quantum structures

Applications include quantum nonlocality witnessing

Abstract

Uncertainty principle is an inherent nature of quantum system that undermines the precise measurement of incompatible observables and hence the applications of quantum theory. Entanglement, another unique feature of quantum physics, was found may help to reduce the quantum uncertainty. In this paper, we propose a practical method to reduce the one party measurement uncertainty by determining the measurement on the other party of an entangled bipartite system. In light of this method, a family of conditional majorization uncertainty relations in the presence of quantum memory is constructed, which is applicable to arbitrary number of observables. The new family of uncertainty relations implies sophisticated structures of quantum uncertainty and nonlocality, that were usually studied by using scalar measures. Applications to reduce the local uncertainty and to witness quantum nonlocalities are also presented.