Quantum discord in de Sitter space

Abstract

We study quantum discord between two free modes of a massive scalar field in a maximally entangled state in de Sitter space. We introduce two observers, one in a global chart and the other in an open chart of de Sitter space, and the observers determine the quantum discord created by each detecting one of the modes. This situation is analogous to the relationship between an observer in a Minkowski chart and another in one of the two Rindler charts in flat space. We find that the state becomes less entangled as the curvature of the open chart gets larger. In particular, for the cases of a massless, and a conformally coupled scalar field, the entanglement vanishes in the limit of infinite curvature. However, we find that the quantum discord never disappears even in the limit that entanglement disappears.

19 pages, 9 figures

References in corpus (9)

• Entanglement of Dirac fields in non-inertial frames
• Entanglement in an expanding spacetime
• Entanglement entropy of $\alpha$-vacua in de Sitter space
• Impact of quantum entanglement on spectrum of cosmological fluctuations
• Entanglement negativity in the multiverse
• The Quantum Information of Cosmological Correlations
• Cosmological Consequences of Initial State Entanglement
• Observer dependence of bubble nucleation and Schwinger pair production
• Vacua and correlators in hyperbolic de Sitter space