Berlin 2012 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 24: Nanomechanics

TT 24.11: Vortrag

Mittwoch, 28. März 2012, 12:15–12:30, H 3005

Adiabaticity in semiclassical nanoelectromechanical systems — •Anja Metelmann and Tobias Brandes — Institut für Theoretische Physik, TU Berlin, Hardenbergstr. 36, D-10623 Berlin, Germany

We compare the semiclassical description of NEMS within and beyond the adiabatic approximation. We consider a NEMS model which contains a single phonon (oscillator) mode linearly coupled to an electronic few-level system in contact with external particle reservoirs (leads). Using Feynman-Vernon influence functional theory, we derive a Langevin equation for the oscillator trajectory that is non-perturbative in the system-leads coupling. A stationary electronic current through the system generates nontrivial dynamical behavior of the oscillator, even in the adiabatic regime. The backaction of the oscillator onto the current is studied as well [1].
For the case of two coupled electronic levels, we discuss the differences between the adiabatic and the non-adiabatic regime of the oscillator dynamics.

[1] A. Metelmann and T. Brandes, Phys. Rev. B 84, 155455 (2011).