|Location: Hörsaal A
Time: Monday 16.11.2009, 14h c.t.
Nano-electromechanical systems (NEMS) make use of electrically induced mechanical motion and vice versa. NEM-devices are the successors of micro-electromechanical systems (MEMS) that already have applications in information technology, transport industry and medicine. Exploiting NEMS technology improves performance in terms of speed and power consumption. From a more fundamental point of view, the ongoing miniaturization of mechanical systems also enables the study of new phenomena because NEMS are in an unexplored regime of motion thereby approaching the fundamental detection limit set by quantum mechanics.
In this talk I will review our work on transport through suspended carbon nanotubes. At room temperature, mixing techniques are used to probe the bending-mode vibration of a suspended carbon nanotube. At low temperatures, mechanical vibrations are actuated by a nearby antenna and a record high Q-value of 150000 at a resonance frequency of 300 MHz is achieved. Electron transport and mechanical motion are strongly coupled resulting in electron tuning oscillations of the mechanical frequency, energy transfer to the electrons causing mechanical damping and unusual non-linear behavior. Strikingly, we also discover that a d.c. current through the nanotube spontaneously drives the mechanical resonator, exerting a force that is synchronized with the high-frequency resonant mechanical motion.
Strong coupling between single-electron tunnelling and nano-mechanical motion
G.A. Steele, A.K. Hüttel, B. Witkamp, M. Poot, H.B. Meerwaldt, L.P. Kouwenhoven and H.S.J. van der Zant, Science 325 (2009) 1103-1107 (DOI: 10.1126/science.1176076).
Carbon nanotubes as ultra-high quality factor mechanical resonators
A.K. Hüttel, G.A. Steele, B. Witkamp, M. Poot, L.P. Kouwenhoven and H.S.J. van der Zant
Nano Lett. 9 (2009), 2547-2552 (DOI 10.1021/nl900612h).