Quantum-classical gravity distinction in reservoir-engineered massive quantum system

TL;DR

This paper proposes a reservoir-engineered approach to distinguish quantum from classical gravity by analyzing steady-state entanglement modifications, which is more robust and feasible than traditional methods requiring high mechanical quality factors.

Contribution

It introduces a novel reservoir-engineered scheme that identifies gravity's quantum nature through entanglement characteristics, relaxing experimental constraints.

Findings

Classical gravity introduces dissipative channels affecting entanglement.

The scheme can differentiate quantum and classical gravity even with low quality factors.

Robustness against non-gravitational forces like Casimir and Coulomb effects.

Abstract

Massive quantum systems have emerged as compelling tabletop interface-systems for testing the quantum nature of gravity. However, conventional schemes that focus on directly using gravity to induce entanglement suffer from overwhelming environmental decoherence: maintaining entanglement between two oscillators requires an impractically high mechanical quality factor. In this work, we put forward an alternative reservoir-engineered scheme, whose core function is to quantify how gravity modifies (rather than prepares) the steady-state entanglement. Compared to quantum gravity, classical gravity introduces additional dissipative channels, which in turn give rise to distinct entanglement characteristics and thus enable the discrimination between the two types of gravity. Notably, this entanglement difference can still be maintained even when the mechanical quality factor is far below the threshold required by conventional schemes. Moreover, it demonstrates significant robustness against non-gravitational couplings, specifically, those like Casimir and Coulomb forces that are inherent in experimental setups. Our scheme relaxes the experimental requirements for verifying quantum gravity, thereby paving a new path toward its near-term realization.