A different perspective on the Landau-Zener dynamics

We present two different approaches towards the Landau-Zener problem: (i) The Markov approximation in the integro-differential equation for one of the two probability amplitudes, and (ii) an amplitude-and-phase analysis of the linear second order differential equation for same probability amplitude. Our treatment shows that the Markov approximation neglects the non-linearity of the equation but still provides us with the exact asymptotic result.