Quantum rainbow characterization of short chiral carbon nanotubes

In this work, we present a study of the quantum angular distributions of 1 MeV positrons channeled through the chiral (7, 3), (8, 5), (9, 7), (14, 4), (16,5) and (17,7) single walled carbon nanotubes (SWCNTs), having the same length of 200 nm and the corresponding nanotube radiuses of 0.35, 0.45, 0.55, 0.65, 0.75 and 0.85 nm, respectively. The continuum positron-nanotube interaction potential was obtained using the thermally averaged Molieres positron-carbon interaction potential. A positron beam is treated as an ensemble of non-interacting quantum particles each represented by a Gaussian wave packet. Evolution of a channeled positron was obtained from the numerical solution of the corresponding time-dependent Schrodinger equation. For the comparison, the classical angular rainbows for cases under the consideration are investigated as well. They were obtained using the numerical solution of the corresponding Newtons equations of positron motion in the transverse plane of carbon nanotube. We show that the quantum angular transmission patterns can be successfully used for the characterization of short chiral carbon nanotubes