Fast noise in the Landau-Zener theory

V. L. Pokrovsky, N. A. Sinitsyn

Published 2002-12-01, updated 2003-02-04Version 3

We study the influence of a fast noise on Landau-Zener transitions. We demonstrate that a fast colored noise much weaker than the conventional white noise can produce transitions itself or can change substantially the Landau-Zener transition probabilities. In the limit of fast colored or strong white noise we derive asymptotically exact formulae for transition probabilities and study the time evolution of a spin coupled to the noise and a sweeping magnetic field.