CMSP Seminar Series @ICTP Stasi Room: F.PISTOLESI Thursday 11 May at 11:30

[Condensed_Matter_Group]

ICTP Seminar Series in Condensed Matter and Statistical Physics
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THURSDAY 11 MAY at 11:30 a.m.

Luigi Stasi Seminar Room, first floor, ICTP Leonardo building
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Speaker: Fabio PISTOLESI
(Lab.Onde et Matiere, Univ.de Bordeaux, CNRS,Talence, France)

Title:
Mechanical Signatures of the Current Blockade Instability
in Suspended Carbon Nanotubes

Abstract:
Transport measurements allow sensitive detection of
nanomechanical motion of suspended carbon nanotubes.
It has been predicted that when the electromechanical
coupling is sufficiently large a bistability with a
current blockade appears. Unambiguous observation of this
transition by current measurements may be difficult.
Instead, we investigate the mechanical response of the
system, namely, the displacement spectral function, the
linear response to a driving, and the ring-down behavior.
We find that by increasing the electromechanical coupling
the peak in the spectral function broadens and shifts at low
frequencies while the oscillator dephasing time shortens.
These effects are maximum at the transition where nonlinearities
dominate the dynamics. These strong signatures open the way to
detect the blockade transition in devices currently studied by
several groups.