Blurred quantum Darwinism across quantum reference frames

TL;DR

This paper explores how the concept of objectivity in quantum Darwinism varies across different quantum reference frames, revealing that objectivity is frame-dependent and influenced by specific quantum properties.

Contribution

It extends quantum Darwinism by analyzing its frame dependence, showing that objectivity is subjective and varies with quantum reference frames.

Findings

Objectivity depends on non-degenerative relative separations.

Objectivity is influenced by environment macro-fractions.

Different reference frames contain different objective information.

Abstract

Quantum Darwinism describes objectivity of quantum systems via their correlations with their environment--information that hypothetical observers can recover by measuring the environments. However, observations are done with respect to a frame of reference. Here, we take the formalism of [Giacomini, Castro-Ruiz, & Brukner. Nat Commun 10, 494 (2019)], and consider the repercussions on objectivity when changing quantum reference frames. We find that objectivity depends on non-degenerative relative separations, conditional state localisation, and environment macro-fractions. There is different objective information in different reference frames due to the interchangeability of entanglement and coherence, and of statistical mixing and classical correlations. As such, objectivity is subjective across quantum reference frames.