Energy dissipation in the double-walled carbon nanotube based mechanical oscillators

摘要

We have performed atomic simulations of double-walled carbon nanotube with the inner shell oscillating inside the outer one at frequencies in the GHz range. It's found that energy exchanging with phonon bath results in a short lifetime of few nanoseconds and low Q-factor about one thousand. Phonon power spectrum analysis confirmed the coupling as the intrinsic source of energy dissipation and its enhancement at higher temperature. The importance of angular symmetry and the instabilities introduced by the atoms in tube ends are discussed, which have been found to contribute remarkably to the energy dissipation and should be treated attentively in practice.