Ad-dimers on Strained Carbon Nanotubes: A New Route for Quantum Dot Formation?

The presence of ad-dimers on carbon nanotubes under tension leads to the formation of defects that wrap themselves around the circumference of the nanotube. These defects are actually short segments of a tube with a changed helicity, which suggests that the combination of ad-dimers plus strain can be used to form nanotube-based quantum dots. Our classical molecular dynamics and tight binding simulations show that the formation of such structures is particularly clean and promising for the $\left(n,0\mathrm{}\right)$ zigzag tubes, where the presence of ad-dimers induces plastic transformations on what are otherwise brittle tubes.