CRG-B - Thermal neutron interferometer

Quantum entanglement

With a similar experimental arrangement as for the previous example the entanglement in a single-neutron system of external and internal degrees of freedom has been measured.
This demonstrated for the first time quantum contextuality and the feasibility to produce Greenburger-Horne-Zeilinger states of neutrons.

Ref.: Hasegawa Y. , Loidl R. , Badurek G. , Filipp S. , Klepp J. , Rauch H., Physical Review A 76, 052108-1-052108-6 (2007).