Competitions between quantum correlations in the quantum-memory-assisted entropic uncertainty relation

TL;DR

This paper explores how quantum memory affects measurement uncertainty bounds in quantum systems, revealing a competitive relationship between quantum and classical correlations among multiple parties.

Contribution

It introduces a novel analysis of the competition between quantum and classical correlations influencing uncertainty bounds in multi-party quantum systems.

Findings

Quantum memory reduces uncertainty bounds for the measured system.

The reduction in uncertainty bound increases for a third participant.

Uncertainty bounds are governed by the interplay of quantum and classical correlations.

Abstract

With the aid of a quantum memory, the uncertainty about the measurement outcomes of two incompatible observables of a quantum system can be reduced. We investigate this measurement uncertainty bound by considering an additional quantum system connected with both the quantum memory and the measured quantum system. We find that the reduction of the uncertainty bound induced by a quantum memory, on the other hand, implies its increasing for a third participant. We also show that the properties of the uncertainty bound can be viewed from perspectives of both quantum and classical correlations, in particular, the behavior of the uncertainty bound is a result of competitions of various correlations between different parties.