Testing the nonclassicality of gravity with the field of a single delocalized mass

TL;DR

This paper proposes a novel experimental setup to test the quantum nature of gravity using a single delocalized mass and a harmonically trapped test mass, focusing on feasibility and Casimir-Polder force management.

Contribution

It introduces a new experimental design that relies on a single delocalized mass and explores the role of Casimir-Polder forces in testing gravity's quantum properties.

Findings

Feasibility of the proposed experiment depends on controlling Casimir-Polder forces.

Design aims to utilize Casimir-Polder forces rather than only mitigate them.

The setup offers a new approach to probing quantum gravity effects with minimal mass configurations.

Abstract

Most of the existing proposals for laboratory tests of a quantum nature of gravity are based on the use of two delocalized masses or harmonically bound masses prepared in pure quantum states with large enough spatial extent. Here a setup is proposed that is based on a single delocalized mass coupled to a harmonically trapped test mass (undergoing first expansion and then compression) that moves under the action of gravity. We investigate the in-principle feasibility of such an experiment, which turns out to crucially depend on the ability to tame Casimir-Polder forces. We thus proceed with a design aimed at achieving this, trying at the same time to take advantage of these forces rather than only fighting them.