Thermal Conductivity and Phonon Scattering in Severely Bent Carbon Nanotubes and Bi-layer Graphene

The combination of high thermal conductivity and mechanical resilience makes carbon nanotubes and few-layer graphene interesting systems to investigate phonon scattering on the nonlinear structural buckling. This fundamental limit of heat transfer has not been so far detected, partly because of the extraordinary experimental difficulties encountered at this scale. Utilizing non-equilibrium molecular dynamics with classical inter-atomic potentials, we study thermal transport in severely bent single-wall carbon nanotube and bi-layer graphene structures. These bent structures were computed with atomistic-level calculations performed under objective boundary conditions, which allow imposing a pure bending moment. We show that at lengths much shorter than the mean free path, local buckling can significantly decrease the thermal conductivity. Our calculations provide guidance for the experimental lengths required to observe phonon-buckling scattering effect in these structures.