Speaker
Description
Entanglement generation is often regarded as evidence that the interaction responsible for it is quantum, and has become a central ingredient in many recent proposals to probe the quantum nature of gravity and other fundamental interactions. In this talk we revisit this intuition by asking a simple question: what features of an interaction are truly required to generate entanglement? We discuss how two quantum systems can become entangled through interactions that admit effective descriptions without local quantum mediators, and how such descriptions can reproduce the predictions of fully quantum field-theoretic models within their regime of validity. We then show where these effective descriptions inevitably fail, revealing the role of relativistic causality in delimiting their validity and clarifying what entanglement generation can (and cannot) tell us about the quantumness of the underlying interaction. Together, these results provide a more nuanced perspective on mediator-free models, the quantum channels they enable, and the operational meaning of quantum interactions, thereby sharpening the theoretical framework for interpreting (and improving the design of) future experiments that probe the quantum nature of gravity.