Testing the nonclassicality of spacetime: what can we learn from Bell-Bose et al.-Marletto-Vedral experiments?

TL;DR

This paper proposes extending the BMV experiment to include Bell tests with distant particles, aiming to more conclusively demonstrate the nonclassical nature of spacetime by ruling out local hidden variable theories.

Contribution

It introduces a novel extension of the BMV experiment involving Bell inequalities to strengthen evidence for spacetime nonclassicality.

Findings

Bell inequality violation would exclude LHVTs

Extension enhances the proof of spacetime nonclassicality

Proposes experimental setup for combined gravity and quantum tests

Abstract

The Bose et al.-Marletto-Vedral (BMV) experiment [S. Bose et al., Phys. Rev. Lett. 119, 240401 (2017); C. Marletto and V. Vedral, Phys. Rev. Lett. 119, 240402 (2017)] aims to prove that spacetime is nonclassical by observing entanglement generated by gravity. However, local hidden variable theories (LHVTs) can simulate the entangled correlations. We propose to extend the entanglement generated by the BMV experiment to distant quantum particles in a Bell experiment. Violating a Bell inequality would rule out LHVTs, providing a stronger proof of the nonclassicality of spacetime than the BMV proposal.