Regensburg 2004 – wissenschaftliches Programm

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TT: Tiefe Temperaturen

TT 22: Quantenkoh
ärenz und Quanteninformationssysteme I

TT 22.11: Vortrag

Mittwoch, 10. März 2004, 17:00–17:15, H19

Macroscopic quantum effects in driven nanomechanical wires — •Vittorio Peano and Michael Thorwart — Institut für Theoretische Physik IV, Heinrich-Heine-Universität Düsseldorf

We investigate the nonlinear response of a vibrating doubly clamped suspended nanomechanical wire on an externally applied periodic driving. The setup can be mapped onto the dynamics of a quantum particle moving in a monostable quartic potential which is driven by an ac-field. The quantum system is weakly damped due to interaction with a harmonic bath. By solving the corresponding Born-Markovian master equation for the reduced density operator, we calculate the response of the system for varying driving frequencies. For strong driving, we observe characteristic resonances which are absent in the corresponding classical model. The resonances are explained in terms of tunneling transitions in the dynamically induced effectively bistable system which is obtained within the Floquet theory. Applications of the model to nanowires as well as to driven SQUIDs are discussed.

17:15 Pause