Distribution and Generation of Quantum Coherence for Gaussian States in de Sitter Space

• Published in: Annalen der Physik Vol. 533; no. 4
• Main Authors: Liu, Qianqian, Wen, Cuihong, Wang, Jieci, Jing, Jiliang
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.04.2021
• Subjects: Charts; Coherence; Curvature; curved spacetime; de Sitter space; entanglement; quantum coherence; Quantum entanglement; Quantum mechanics; Quantum phenomena; Scalars; Steering
• ISSN: 0003-3804; 1521-3889
• DOI: 10.1002/andp.202000536

The distribution and generation of quantum coherence for two‐mode and multi‐mode Gaussian states in de Sitter space are studied. It is found that the quantum coherence is redistributed among the mode in different open charts under the curvature effect of de Sitter space. In particular, the Gaussian coherence for the initially correlated state is found to survive in the limit of infinite curvature, while quantum entanglement vanishes in this limit. Unlike entanglement and steering, the coherence of a massive scalar field is more robust than a massless field under the influence of curvature of de Sitter space. In addition, it is shown that the curvature generates two‐mode Gaussian state and three‐mode Gaussian state quantum coherence among the open charts, even though the observers are localized in causally disconnected regions. It is worth noting that the gravity‐generated three‐mode coherence is extremely sensitive to the curvature effect for the conformal and massless scalar fields, which may be in principle employed to design an effective detector for the space curvature. The distribution and generation of quantum coherence for the bipartite and tripartite Gaussian states in de Sitter space are discussed. It is shown that the curvature parameter and the mass parameter of the de Sitter space affect the coherence between Gaussian states, even if the observers are localized in causally disconnected regions.