Non-Adiabatic Transition in Spin-Boson Model and Generalization of the Landau-Zener Formula

摘要

Non-adiabatic transitions are studied in a spin-boson model with multiplescattering points. In order to generalize the Landau-Zener formula, whichdescribes the case of a single scattering point, we define an ``effective gap''for a set of scattering points. The generalized formula agrees very well withnumerical results of the non-adiabatic dynamics, which we obtained by a directnumerical method. This will make the Landau-Zener formula yet more useful inanalyzing experimental data of magnetic-moment inversion.