TiO2 Nanowires as a Wide Bandgap Dirac Material: a numerical study of impurity scattering and Anderson disorder

Dirac materials are characterized by exceptional mobility, orders of magnitude higher than any semiconductor, due to the massless pseudorelativistic nature of the Dirac fermions. These systems being semimetallic, the lack of a genuine band-gap poses a serious limitation to their possible applications in electronics. We recently demonstrated that thin TiO2 nanowires can exhibit 1D Dirac states similar to metallic carbon nanotubes, with the crucial difference that these states lie inside the conduction band in proximity of a wide band gap. We analyze the robustness of the Dirac states respect to an Anderson disorder model and substitutional impurity and compare to different one dimensional systems. The results suggest that thin anatase TiO2 nanowires can be a promising candidate material for switching devices.