Anomalous dissipation in single-walled carbon nanotube resonators.

We observe a new anomalous and transient process of intrinsic dissipation in simulations of the ring-down of flexural modes in single-walled carbon nanotube (CNT) resonators. The effect is pronounced, causing the quality factor of the mode to be reduced by more that 95% for tens of picoseconds. The anomalous dissipation depends on the CNT temperature and the energy in the mode, and remarkably increasing the excitation energy in the resonator causes it to decay to zero faster. By tracking the cascade of energy as it dissipates we identify "gateway" modes that provide important channels for dissipation. The processes we observe show that an athermal phonon population accompanying dissipation can strongly influence the quality factor in nanoelectromechanical devices.