Proving the Generation of Genuine Multipartite Entanglement in a Single-Neutron Interferometer Experiment

TL;DR

This paper demonstrates the experimental generation and detection of genuine multipartite entanglement within single-neutron systems, showcasing advanced control and measurement techniques for quantum entanglement.

Contribution

It introduces new neutron spin manipulation apparatuses and optimized non-linear witnesses to generate and verify multipartite entanglement in single-neutron interferometry.

Findings

Successful generation of genuine tripartite entanglement

High fidelity of entangled states achieved

Enhanced understanding of entanglement properties in neutron systems

Abstract

We present experimental evidence of the generation of distinct types of genuine multipartite entanglement between three degrees of freedom, two internal and one external degree of freedom, within single-neutron quantum systems. This is achieved via the development of new spin manipulation apparatuses for neutron interferometry and the genuine multipartite entanglement is detected via appropriately designed and optimized non-linear witnesses. Via the applied criteria we reveal even finer properties of the type of the genuine multipartite entanglement that is produced in the experiment. In a subsequent analysis we show the extraordinarily high fidelity of genuine tripartite entangled states, proving the outstanding level of controllability of these systems.