Probing the Non-Classicality of Temporal Correlations

Abstract

Correlations between spacelike separated measurements on entangled quantum systems are stronger than any classical correlations and are at the heart of numerous quantum technologies. In practice, however, spacelike separation is often not guaranteed and we typically face situations where measurements have an underlying time order. Here we aim to provide a fair comparison of classical and quantum models of temporal correlations on a single particle, as well as timelike-separated correlations on multiple particles. We use a causal modeling approach to show, in theory and experiment, that quantum correlations outperform their classical counterpart when allowed equal, but limited communication resources. This provides a clearer picture of the role of quantum correlations in timelike separated scenarios, which play an important role in foundational and practical aspects of quantum information processing.

8 pages, 6 figures, 2 pages appendix, Accepted version

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Cited by in corpus (12)

• Quantum Markov Order
• The Structure of Quantum Stochastic Processes with Finite Markov Order
• Quantum violation of an instrumental test
• Concentration phenomena in the geometry of Bell correlations
• A Unifying Framework for Spatial and Temporal Quantum Correlations
• Leggett-Garg Macrorealism and temporal correlations
• Experimental Demonstration of Instrument-specific Quantum Memory Effects and Non-Markovian Process Recovery for Common-Cause Processes
• Temporal correlations in the simplest measurement sequences
• Quantum steering beyond instrumental causal networks
• Memory Effects in Quantum Processes
• Quantum correlations with a gap between the sequential and spatial cases
• Causal Networks and Freedom of Choice in Bell's Theorem