A One-sided Witness for the Quantumness of Gravitational Dynamics

TL;DR

This paper proposes a novel one-sided method to verify the quantum nature of gravity using verifiable quantum memory, enabling local measurements on a single subsystem to detect quantum gravitational interactions.

Contribution

It introduces a new indirect test for quantum gravity based on verifiable quantum memory, allowing one-sided verification through local measurements.

Findings

First one-sided verification of quantum gravity

Provides a quantum signature not covered by existing proposals

Enables witnessing quantum gravity in tabletop experiments

Abstract

Quantum information concepts and quantum technologies have opened the prospect to probe quantum gravity in table-top experiments. Many proposals rely on witnessing entanglement generation as a means to probe whether gravity is a quantum channel. Here we formulate a different and conclusive indirect test of the quantum nature of the gravitational interaction. Our witness is based on the concept of verifiable quantum memory in the dynamics of a quantum system. This allows us to assess the quantumness of an interaction between two systems by local measurements on one subsystem only. Our approach enables the first one-sided verification of the quantum nature of gravity, and provides a quantum signature of the interaction that is not fully covered by existing proposals. Our results open novel ways to witnessing the quantum nature of gravity in table-top experiments and clarify how {decisive tests can be designed even with measurements on only the probe system