Journal of Physics A Mathematical and General
Spin-1/2 system coupled to a single mode: a resolvent expansion of the time-dependent solution
Karl Zeile, E. Sigmund, P. Schwendimann
Abstract
In order to describe the dynamics of a spin-oscillator Hamiltonian analytically, a second-order differential equation for the transition probability amplitude is established by means of a transcription into the Bargmann space of entire functions. The solution of the differential equation is given by a resolvent expansion whose zeroth-order member is in general exact up to fourth order in time; for various degenerate parameter values, however, it is exact for all times. The Laplace transform of any higher-order member is given explicitly.