Effects of dangling ends on the conductance of side-contacted carbon nanotubes

We have computed the conductance of a side-contacted metallic carbon nanotube (CNT) with one end dangling outside a probe by using a tight-binding model. We have also demonstrated that the average conductance of a CNT with a finite dangling end is about twice as that of CNT with an infinite dangling end. When the contact between a side probe and a CNT is monoatomic, the conductance strongly depends on the length of the dangling end. Quasilocalized states at the dangling end can cause antiresonances, affecting transmission probability when a probe is near the end.