Electronic and transport properties of single-wall carbon nanotubes encapsulating fullerene-based structures

We investigate electronic and transport properties of (10,10) carbon nanotubes that contain a finite-sized capped (5,5) tube (capsule) and a long chain of C-60 fullerenes by using the tight-binding model. We find that the total transmissions through the outer tubes are very sensitive to the symmetry of the hybrid tubes. For the (10,10) tube where the (5,5) capsule is aligned so as to maintain mirror symmetries, the total transmission exhibits antiresonances with symmetric line shapes, while breaking mirror symmetries leads to asymmetric line shapes. For encapsulated fullerenes in the (10,10) tube, we find rich structures in transmission, such as antiresonances, resonances, and transmission gaps, which depend on mirror and rotational symmetries. This feature is attributed to the fact that the coupling of incident channels with the bound states of the inner structures is determined by the symmetry of the hybrid tubes.