Interference and k-point sampling in the supercell approach to phase-coherent transport
arXiv:cond-mat/0411589 · doi:10.1103/PhysRevB.72.033401
Abstract
We present a systematic study of interference and k-point sampling effects in the supercell approach to phase-coherent electron transport. We use a representative tight-binding model to show that interference between the repeated images is a small effect compared to the error introduced by using only the Gamma-point for a supercell containing (3,3) sites in the transverse plane. An insufficient k-point sampling can introduce strong but unphysical features in the transmission function which can be traced to the presence of van Hove singularities in the lead. We present a first-principles calculation of the transmission through a Pt contact which shows that the k-point sampling is also important for realistic systems.
4 pages, 5 figures. Accepted for Phys. Rev. B (Brief Report)