Evolution of tripartite entanglement in three-qubit Quantum Gravity-Induced Entanglement of Masses (QGEM) with quantum decoherence

TL;DR

This paper investigates how three-qubit quantum gravity experiments (QGEM) generate and detect genuine tripartite entanglement under decoherence, highlighting the resilience and experimental configurations for observing quantum gravity effects.

Contribution

It analyzes the generation of genuine tripartite entanglement in three-qubit QGEM setups considering decoherence effects and compares different configurations for optimal entanglement detection.

Findings

Gravitational interaction can produce genuine tripartite entanglement.

Certain experimental configurations are more resilient to decoherence.

Detection of entanglement depends on specific parameter regimes.

Abstract

The recently introduced quantum gravity-induced entanglement of masses (QGEM) protocol aims to test the quantum nature of gravity by witnessing the entanglement produced by the virtual exchange of a graviton between two spatially superposed masses. Shortly after the original proposal, further improvements upon the experiment were suggested, including the addition of a third mass, showing that three-qubit setups can be more resilient to higher rates of decoherence caused by the interaction of the system with the environment. In this work, we investigate the type of tripartite entanglement generated in these three-qubit QGEM experiments when considering the effects of decoherence. We show that the gravitational interaction between the qubits is able to generate genuine tripartite entanglement between them, studying the corresponding parameter spaces and comparing the performance of the possible experimental configurations of the three qubits at allowing for the detection of genuine entanglement via an entanglement witness.