Exact solutions for neutral particles in the field of a circularly polarized plane electromagnetic wave

The Schrödinger equation for a neutral particle with general spin and magnetic moment moving in the field of a circularly polarized plane electromagnetic wave is solved exactly. Simple cyclic solutions are presented for general spin, and more complicated ones for spin 1/2. Many properties of the solutions, including time evolution of the spin vector, nonadiabatic geometric phase, etc. are studied in detail.