  The oscillatory response of nonlinear systems exhibits characteristic
phenomena such as multistability, discontinuous jumps and hysteresis. These can
be utilized in applications leading, e.g., to precise frequency measurement,
mixing, memory elements, reduced noise characteristics in an oscillator or
signal amplification. Approaching the quantum regime, concepts have been
proposed that enable low backaction measurement techniques or facilitate the
visualisation of quantum mechanical effects. Here we study the dynamic response
of nanoelectromechanical resonators in the nonlinear regime aiming at a more
detailed understanding and an exploitation for switching applications. Whereas
most previous investigations concentrated on dynamic phenomena arising at the
onset of bistability, we present experiments that yield insight into the
non-adiabatic evolution of the system while subjected to strong driving pulses
and the subsequent relaxation. Modeling the behaviour quantitatively with a
Duffing oscillator, we can control switching between its two stable states at
high speeds, exceeding recently demonstrated results by 10,000.
