Contextuality from the vacuum

TL;DR

This paper demonstrates that quantum vacuum fluctuations can be a source of contextuality, which can be extracted using Unruh-DeWitt detectors, linking it to quantum advantages and Wigner negativity.

Contribution

It introduces the concept of harvesting contextuality from the quantum vacuum using localized detectors, connecting it to Wigner negativity and relativistic quantum information.

Findings

Localized interactions induce contextuality in detectors.

Harvested contextuality correlates with Wigner function negativity.

Contextuality can be directly extracted from the quantum vacuum.

Abstract

Contextuality, a key resource for quantum advantage, describes systems in which the outcome of a measurement is not independent of other compatible measurements, in contrast to classical hidden-variable descriptions. We investigate the harvesting of contextuality from the vacuum of a quantum field using Unruh-DeWitt detectors. We show that localized interactions with the field can endow initially non-contextual detectors with contextuality with respect to Heisenberg-Weyl measurements, as quantified by contextual fraction. The harvested contextuality correlates with the emergence of Wigner function negativity, in agreement with known equivalences between these notions. Our results show that contextuality is a resource that can be extracted directly from the quantum vacuum and establish contextuality harvesting as a fundamental phenomenon in relativistic quantum information.