Locally Mediated Entanglement in Linearized Quantum Gravity

The current interest in laboratory detection of entanglement mediated by gravity was sparked by an information-theoretic argument: entanglement mediated by a local field certifies that the field is not classical. Previous derivations of the effect modeled gravity as instantaneous; here we derive it from linearized quantum general relativity while keeping Lorentz invariance explicit, using the path-integral formalism. In this framework, entanglement is clearly mediated by a quantum feature of the field. We also point out the possibility of observing retarded entanglement, which cannot be explained by an instantaneous interaction. This is a difficult experiment for gravity, but is plausible for the analogous electromagnetic case.

Automated summary

The interest in laboratory detection of entanglement mediated by gravity arises from an information-theoretic argument that entanglement mediated by a local field certifies the non-classical nature of the field. Previous derivations of this effect assumed gravity to be instantaneous, but here we derive it from linearized quantum general relativity while explicitly maintaining Lorentz invariance using the path-integral formalism. In this framework, entanglement is clearly demonstrated to be mediated by the quantum nature of the field. We also highlight the possibility of observing retarded entanglement, which cannot be explained by instantaneous interaction. This experiment is challenging for gravity but plausible for the analogous electromagnetic case.