# Dynamical transitions in a modulated Landau-Zener model with finite driving fields. (arXiv:1709.04181v1 [quant-ph])

We investigate a special time-dependent quantum model which assumes the

Landau-Zener driving form but with an overall modulation of the intensity of

the pulsing field. We demonstrate that the dynamics of the system, including

the two-level case as well as its multi-level extension, is exactly solvable

analytically. Differing from the original Landau-Zener model, the nonadiabatic

effect of the evolution in the present driving process does not destroy the

desired population transfer. As the sweep protocol employs only the finite

driving fields which tend to zero asymptotically, the cutoff error due to the

truncation of the driving pulse to the finite time interval turns out to be

negligibly small. Furthermore, we investigate the noise effect on the driving

protocol due to the dissipation of the surrounding environment. The losses of

the fidelity in the protocol caused by both the phase damping process and the

random spin flip noise are estimated by solving numerically the corresponding

master equations within the Markovian regime.