Can Newtonian Gravity Produce Quantum Entanglement?

TL;DR

This paper examines whether Newtonian gravity can generate quantum entanglement between mesoscopic bodies, finding that certain quantum models support entanglement while classical models do not, clarifying ongoing debates.

Contribution

It compares different gravity models and demonstrates that quantized gravitational fields can produce entanglement, unlike classical or stochastic models.

Findings

Mini-superspace quantization can entangle quantum bodies.

Classical and stochastic gravity models fail to produce entanglement.

Clarifies misconceptions about classical gravity's role in quantum entanglement.

Abstract

We investigate whether Newtonian gravity can generate quantum entanglement between mesoscopic quantum bodies modeled as superposed mass quadrupoles using three complementary approaches: mini-superspace, semiclassical gravity, and stochastic gravity. We systematically analyze gravitationally induced entanglement (GIE) mechanisms and the conditions under which they can arise. Our results support the GIE hypothesis by showing that the mini-superspace framework, which quantizes the parity of the gravitational tidal field, can entangle spatially separate quantum bodies. In contrast, the semiclassical and stochastic gravity models, in which the tidal gravitational field sourced by the quantum bodies remains classical, fail to entangle the final state. These findings clarify recent claims that classical gravity might induce entanglement, and reveal how perturbative treatments can lead to misleading conclusions.