Energetics and Bandstructure for a Polyacetylene Chain Enclosed inside a Carbon Nanotube

Using density functional theory, we calculate the energy and bandstructure properties of a polyacetylene chain enclosed inside various armchair carbon nanotubes. We find that (4,4) and (5,5) nanotubes are too narrow to contain a polyacetylene chain, while (6,6) nanotubes and wider are energetically favoured to contain one or more polyacetylene chains. Bandstructure calculations reveal that there is some interaction between the enclosed polyacetylene chain and carbon nanotube. Interestingly, we find that this interaction causes a sharp peak to appear in the density of states near the Fermi level, which could facilitate a transition to a superconducting phase.