Controlling Gaussian Rényi-2 entropy, Gaussian geometric discord and Gaussian Rényi-2 classical correlations in de sitter spacetime

Abstract

We study the distribution of bipartite and tripartite quantum entanglement across causally disconnected regions (open charts) in de Sitter spacetime. We first consider a two-mode squeezed state shared between Alice and Bob, where the Gaussian channel models the effects of spacetime curvature. We employ Gaussian Rényi-2 entanglement as a witness for quantum entanglement, while Gaussian geometric discord is a measure of quantumness beyond entanglement, including entanglement. The Gaussian Rényi-2 classical correlations are used to quantify the correlations. Besides, we achieve tripartite entanglement among the open chart modes, quantified by residual Gaussian Rényi-2 entanglement. Our results demonstrate the generation of bipartite entanglement between spatially separated observers due to strong curvature. The impact of curvature on both classical and quantum correlations is shown to be particularly pronounced for conformal and massless scalar fields. Hence, residual Gaussian Rényi-2 entanglement is generated among the open chart modes due to the influence of de Sitter curvature for all nonzero squeezing values.