Premium
Negative frequency tuning of a carbon nanotube nano‐electromechanical resonator under tension (Phys. Status Solidi B 12/2013)
Author(s) -
Stiller P. L.,
Kugler S.,
Schmid D. R.,
Strunk C.,
Hüttel A. K.
Publication year - 2013
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201370581
Subject(s) - carbon nanotube , materials science , mechanical resonance , resonator , resonance (particle physics) , optoelectronics , resistive touchscreen , nanotube , physics , nanotechnology , condensed matter physics , vibration , atomic physics , acoustics , electrical engineering , engineering
On the back cover, a single wall carbon nanotube is displayed (thin black line in the sketch) that is grown across a trench and contact electrodes (green), cooled to milli‐Kelvin temperatures, and then characterized in electronic transport measurements. A quantum dot forms within the suspended segment at these temperatures. The typical Coulomb “diamond” pattern of differential conductance displays distinct signatures of electromechanical feedback and self‐excitation (background measurement, yellow arrows). Using a radio‐frequency cw source, driven mechanical resonances of the nanotube can be detected in dc transport ‐ as exemplified by the red line, a measurement of time‐averaged dc current as a function of the driving frequency. Stiller et al. (pp. 2518–2522 ) find higher harmonic resonances at integer multiples of the fundamental frequency, indicating that the nanotube is a string under tension. Applying a finite gate voltage to the highly doped chip substrate (light blue), the mechanical resonance strongly shifts to lower frequencies. This can be explained by electrostatic softening of the vibration mode.