Signatures of the quantum nature of gravity in the differential motion of two masses

TL;DR

This paper proposes that quantum gravity can be evidenced by squeezing in the relative motion of two masses, which can be detected via an optical interferometric scheme, offering a practical way to test quantum gravitational effects.

Contribution

It introduces a novel method to detect quantum features of gravity through differential motion squeezing and proposes an interferometric scheme for experimental verification.

Findings

Quantum squeezing of relative mass motion indicates quantum gravity effects

The proposed interferometric scheme can test gravity models

Squeezing detection is more feasible than entanglement detection

Abstract

We show that a signature of the quantum nature of gravity is the quantum mechanical squeezing of the differential motion of two identical masses with respect to their common mode. This is because the gravitational interaction depends solely on the relative position of the two masses. In principle, this squeezing is equivalent to quantum entanglement between the masses. In practice, detecting the squeezing is more feasible than detecting the entanglement. To that end, we propose an optical interferometric scheme to falsify hypothetical models of gravity.