Carbon-based nanorings sliding along inner coaxial nanotubes: Möbius topology effects in damping gigahertz oscillations

The axial sliding of carbon-based normal nanorings (NCNs) and one-turn Mobius nanorings (MCNs) along inner coaxial carbon nanotubes with hydrogen-terminated edges is described. Classical molecular dynamics simulations were carried out to investigate their sliding considering C300H100 NCN and MCN nanostructures and single wall armchair carbon nanotubes (SW CNTs) with chiralities (16, 16), (18, 18), and (20, 20). The NCN:CNT system exhibited an oscillatory movement with an initial frequency of about 10 gigahertz decaying slowly with time as the vibrational energy is transferred to radial and torsional modes of the nanoring, while the amplitude remained practically constant except for the (16, 16)-CNT. The MCN:CNT systems, on the other hand, initially oscillated as the NCN:CNT, but a strong damping regime ensued due to the strong interaction of the twisted nanoring with the CNT tips, effectively stopping the oscillation after 400 ps for all MCN:CNT structures investigated.