Adiabatic series expansion and higher-order semiclassical approximations in scattering theory
Journal of Physics A: Mathematical and Theoretical
The scattering properties of any complex scattering potential, v:R -> C, can be obtained from the dynamics of a particular non-unitary two-level quantum system S_v. The application of the adiabatic approximation to S_v yields a semiclassical treatment of the scattering problem. We examine the adiabatic series expansion for the evolution operator of S_v and use it to obtain corrections of arbitrary order to the semiclassical formula for the transfer matrix of v. This results in a high-energy
... oximation scheme that unlike the semiclassical approximation can be applied for potentials with large derivatives.