Gravitationally-induced Conversion of Local Coherence to Entanglement

TL;DR

This paper demonstrates that gravitational interactions can convert local quantum coherence into bipartite entanglement, providing a resource-theoretic understanding of gravity-induced quantum correlations and establishing initial coherence as a necessary condition.

Contribution

It introduces a framework showing gravity acts as a coherence-to-entanglement conversion channel, with analytical relations linking coherence decay to entanglement growth, supported by numerical simulations.

Findings

Gravity acts as a unitary channel redistributing quantum resources.

Initial local coherence is necessary for entanglement generation.

Maximum entanglement requires initial maximal coherence.

Abstract

In recent years, the quantum nature of gravity has attracted significant attention as one of the most important problems in modern physics. Here, we analyze the mechanism of gravitationally-induced entanglement from the perspective of quantum resource theory. Building on the framework of Bose et al. [Phys. Rev. Lett. 119, 240401 (2017)], we show that the gravitational interaction acts as a unitary channel, redistributing quantum resources between two spatially superposed masses. Specifically, we demonstrate that the resulting bipartite entanglement originates from the coherent conversion of local quantum coherence -- initially present in each subsystem -- into shared non-local correlations. We derive exact, analytical complementarity relations quantifying this conversion, link the decay of local coherence directly to the growth of entanglement, and support these findings with numerical simulations. Our results clarify the underlying mechanism and establish gravity as a coherence-to-entanglement conversion channel, offering a refined interpretive basis for forthcoming experimental tests. Crucially, we show that initial coherence is a necessary condition for entanglement generation and that its degree bounds the maximum achievable entanglement, with maximal entanglement requiring initial maximal coherence.