Near-surface quantum states of neutrons in the gravitational and centrifugal potentials

Two related physical phenomena have recently been observed: quantum states of ultracold neutrons (UCN) in the gravitational field above a flat mirror, and quantum states of cold neutrons (CN) in an effective centrifugal potential in the vicinity of a concave mirror. The two phenomena are similar in terms of their associated experimental methods and mathematical representations as well as in terms of their applications in particle physics, quantum optics, and surface physics.