Surprising behaviour during dissipation and collision of flexural waves in carbon nanotubes

Abstract

The manuscript reports on simulations of the intrinsic dissipation of standing and travelling flexural vibrations in carbon nanotubes. It is found that extended travelling and standing waves exhibit anomalous dissipation, during which the excited modes experience massive damping that is triggered by the accumulation of energy in special gateway modes. In the second part of this work the attenuation of travelling flexural wave packets is examined—including the collisions between wave packets. Surprisingly, these wave packets show markedly different dissipation behaviour from extended waves with the same wavelength and amplitude. Moreover, the wave packet collisions are seen to be sensitive to the direction of collision, hinting at temperature gradient induced reduction of the thermal conductivity. Following the cascade of energy as it dissipates it is seen that scattering of energy into other flexural modes has little effect on the net energy flux, while dissipation into non-flexural modes is thermally resistive.