Gaussian quantum discord and the monogamy relation in de Sitter space.

We study the influence of a two-mode Gaussian state under the Gaussian channel that describes the curvature effect in de Sitter space. Interestingly, the classical correlation may be unaffected by the curvature effect, while the quantum discord generally vanishes in the limit of infinite curvature. Under the action of curvature effect, the symmetry of both the classical correlation and quantum discord is destroyed. We obtain a useful monogamy relation for correlations between causally disconnected open charts, which means that quantum discord and classical correlation can convert each other but the total correlation is conserved in de Sitter space. [ABSTRACT FROM AUTHOR]