Gravitational and centrifugal quantum states of neutrons

Two related physical phenomena have recently been observed: quantum states of neutrons in the gravitational field above a flat mirror, and quantum states of neutrons in an effective centrifugal potential in the vicinity of a concave mirror. It is curious that the measurement of the near-surface quantum states of these two types is the first direct demonstration of the weak equivalence principle for a massive object in a quantum state. These two phenomena and their application to various domains of science will be explored using a new GRANIT spectrometer, which is under commissioning in the Institut Laue-Langevin, Grenoble, France. Most recent advances in these domains are mentioned.