A method is described for the exact solution of a nonstationary Shroedinger's equation describing the motion of arbitrary spin in a circulating magnetic field of the form H/sub z/ = H/sub 0/, H = H cos omega t, H/sub y/ = -H sin omega t. (auth)
The case of a quantum two-level system coupled to a time variable magnetic field is investigated. The Schrodinger equation pertaining to the system is reduced to a second order linear equation in time and its solutions are sought by an integrating factor technique. A differential equation for the integrating factor and, therefrom, a criterion for fields leading to exact solutions are derived. The formalism is capable of giving a wide variety of closed form radio frequency (RF) wave forms for which Schrodinger's equation is exactly solvable.