Starts 19 Sep 2017 15:15
Ends 19 Sep 2017 16:15
Central European Time
Leonardo Building - Euler Lecture Hall
I will consider a mesoscopic nanomechanical weak link where electronic transport between leads is blocked by a spin blockade. Namely, a suspended nanowire which is coupled to two oppositely polarized half-metals and subjected to a nonuniform magnetic field. It will be shown that in such system a temperature drop between the leads can significantly affect the dynamics of a mechanical degree of freedom. In particular, it is demonstrated that, under certain conditions, the stationary distribution of the mechanical subsystem has a Boltzmann form with an effective temperature, which is lower than the temperature of the “cold” lead; this seems rather counterintuitive. We also find that a change in the direction of the temperature gradient can result in the generation of mechanical vibrations rather than the heating of the mechanical subsystem. Therefore, the system resembles a nanoelectromechanical heat engine. We derive a criterion for the mechanical instability and estimate the amplitude of the resulting self-sustained oscillations.

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