Can Newtonian Gravity Produce Quantum Entanglement?
Authors
Feng-Li Lin
Sayid Mondal
Abstract
In this note, we consider specific scenarios of matter-gravity interaction based on the source theory to clarify the issue regarding the Gravitationally Induced Entanglement (GIE) protocol, which posits that the detection of quantum entanglement induced by a pure gravitational effect serves as a probe of quantum gravity. Thus, the GIE protocol implies that classical gravity cannot produce or mediate quantum entanglement, to which a recent paper \cite{Aziz:2025ypo} shows the opposite. In all three scenarios of matter-gravity interactions, including mini-superspace, semiclassical gravity, and stochastic gravity approaches, our results agree with the GIE protocol and its implications. More precisely, we show that the mesoscopic quantum bodies with their parities of mass quadrupoles interacting via Newtonian gravity can get entangled only if the parity of the gravitational tidal field sourced by the quantum body is also quantized. We also point out a possible loophole that could seemingly violate the GIE protocol due to the truncation of higher-order terms in the perturbative expansion by orders of the Newton constant.
