# Probing the Non-Classicality of Temporal Correlations

## TL;DR

This paper investigates the differences between classical and quantum temporal correlations on single and multiple particles, demonstrating quantum advantage with limited communication resources through theoretical and experimental analysis.

## Contribution

It provides a comparative analysis of classical and quantum models of temporal correlations, highlighting quantum superiority under constrained communication.

## Key findings

- Quantum correlations outperform classical ones with limited communication.
- Experimental validation supports theoretical predictions.
- Clarifies the role of quantum correlations in timelike scenarios.

## 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.