Nonlinear Dynamics of a Driven Two-Level Tunneling System

Alois W�rger

Andrea Sacchetti

Peter Neu, Jochen Rau

Using the Robertson projection operator formalism, we derive generalized Bloch equations which describe the dynamics of a biased two-level tunneling system strongly driven by an external field and weakly coupled to a super-Ohmic heat bath. The generalized Bloch equations constitute a set of coupled nonlinear integro-differential equations. With their help we investigate the influence of phonons on the phenomenon of dynamical localization.

Orestis Terzidis, Alois W�rger

Frank Großmann, Peter Hänggi A

A periodically driven two-state dynamics, being analysed within the Floquet formalism, exhibits localization of the amplitude dynamics in an infinite frequency range, extending from the bare tunnel splitting up to infinity. In contrast, the suppression of tunnelling in a driven symmetric double well is restricted to a limited frequency regime, extending from the bare tunnel splitting up to the first resonance frequency with higher-lying states. With the amplitude dynamics of a periodically driven two-level system not being restricted to describe coherent tunnelling transport only, the localization phenomenon within the infinite frequency range does allow for novel applications for systems in strong laser fields.

G. Dekel, O. V. Farberovich, Avy Soffer +1 more