Quantum phenomena explored with neutrons

Neutrons are suitable tools for quantum experiments since they are massive, experience nuclear, electromagnetic and gravitational interaction and are easy to manipulate and to detect. Perfect crystal interferometry opened new possibilities to explore quantum phenomena on a new ground. The 4π-symmetry of spinor wave functions, the spin-superposition law, topological quantum phases and various gravitational effects have been examined using this method. Experiments exploiting contextuality and Kochen-Specker phenomena exhibit intrinsic entanglement in single particle systems. This may have consequences for a deeper understanding of quantum physics and for applications in future quantum communication systems. (paper)