A. Nocera, C. A. Perroni, V. Marigliano Ramaglia, V. Cataudella
We propose a microscopic model describing a NanoElectroMechanical System (NEMS) realized by a rf-driven suspended carbon nanotube (CNT) resonator in the presence of an external magnetic field perpendicular to the current flux. As a main result, the magnetic field modifies the bending mode CNT dynamics giving an enhanced damping as well as a noise term originating from the electronic phase fluctuations induced by the CNT displacements. In particular, a quadratic dependence of the device quality factor Q on external magnetic field strength, in quantitative agreement with recent experiments, emerges as a result of a back-action of quantum electronic current-flow fluctuations on the bending mode dynamics. We also show that, when the device is driven far from equilibrium, one can tune electronic and mechanical properties of the resonator by varying the external magnetic field: CNT-resonator resonance frequencies and quality factors acquire, in the limit of large magnetic field, a peculiar behavior as a function of gate and bias voltages that could be experimentally observed.
View original:
http://arxiv.org/abs/1212.0267
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