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.
@article{arxiv.1212.0972,
title = {Proving the Generation of Genuine Multipartite Entanglement in a Single-Neutron Interferometer Experiment},
author = {Daniel Erdösi and Marcus Huber and Beatrix C. Hiesmayr and Yuji Hasegawa},
journal= {arXiv preprint arXiv:1212.0972},
year = {2015}
}