Magnetomotive Instability and Generation of Mechanical Vibrations in Suspended Semiconducting Carbon Nanotubes

Abstract

We have theoretically investigated the electromechanical properties of a freely suspended carbon nanotube that is connected to a constant-current source and subjected to an external magnetic field. We show that self-excitation of mechanical vibrations of the nanotube can occur if the magnetic field $H$ exceeds a dissipation-dependent critical value $H_c$, which we find to be of the order of 10-100 mT for realistic parameters. The instability develops into a stationary regime characterized by time periodic oscillations in the fundamental bending mode amplitude. We find that for nanotubes with large quality factors and a magnetic-field strength just above $H_c$ the frequency of the stationary vibrations is very close to the eigenfrequency of the fundamental mode. We also demonstrate that the magnetic field dependence of the time averaged voltage drop across the nanotube has a singularity at $H=H_c$. We discuss the possibility of using this phenomenon for the detection of nanotube vibrations.

5 pages, 3 figures

References in corpus (7)

• A tunable carbon nanotube electromechanical oscillator
• An Atomic-resolution nanomechanical mass sensor
• Strong coupling between single-electron tunneling and nano-mechanical motion
• Carbon nanotubes as ultra-high quality factor mechanical resonators
• Electrical generation and absorption of phonons in carbon nanotubes
• Quantum Friction in Nanomechanical Oscillators at Millikelvin Temperatures
• Nonlinear resonance in a three-terminal carbon nanotube resonator

Cited by in corpus (4)

• Kondo Force in Shuttling Devices: Dynamical Probe for a Kondo Cloud
• Selfoscillations of Suspended Carbon Nanotubes with a Deflection Sensitive Resistance under Voltage Bias
• Self-sustained oscillations in nanoelectromechanical systems induced by Kondo resonance
• Selective self-excitation of higher vibrational modes of graphene nano-ribbons and carbon nanotubes through magnetomotive instability