We present a recently developed ab initio method based on many-body perturbation theory to calculate the optical absorption spectrum of one-dimensional systems with helical symmetry. Our scheme involves a local, symmetrized basis set which allows for the calculation of large systems otherwise prohibitive in the standard plane-wave approach. It also affords an understanding of the symmetry character of the single-particle states and the excitonic wave functions, which has the advantage of determining in a precise way the selection rules related to the optical transitions of the system in question. We apply our method to single-wall carbon nanotubes of type 4,2 and present the calculated self-energy corrections, absorption spectra, and excitonic states; we ﬁnd that GW corrections are substantial and excitonic effects strongly affect the optical properties.
|Titolo:||First-principles approach for the calculation of optical properties of one-dimensional systems with helical symmetry: The case of carbon nanotubes|
|Autori:||Chang E; Bussi G; Ruini A; Molinari E|
|Rivista:||PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS|
|Data di pubblicazione:||2005|
|Digital Object Identifier (DOI):||10.1103/PhysRevB.72.195423|
|Appare nelle tipologie:||1.1 Journal article|