Unconventional charge and spin-dependent transport properties of a graphene nanoribbon with line-disorder

¹ Department of Physics, Indian Institute of Technology Guwahati - Guwahati-781 039, Assam, India
² Physics and Applied Mathematics Unit, Indian Statistical Institute - 203 Barrackpore Trunk Road, Kolkata-700 108, India

Received: 14 August 2018
Accepted: 23 November 2018

Abstract

Electronic transport with a line (or a few lines) of Anderson-type disorder in a zigzag graphene nanoribbon is investigated in the presence of Rashba spin-orbit interaction. Such line-disorders give rise to a peculiar behavior in both charge as well as spin-polarized transmission in the following sense. In the weak-disorder regime, the charge transport data show Anderson localization up to a certain disorder strength, beyond which the extended states emerge and start dominating over the localized states. These results are the hallmark signature of a selectively disordered (as opposed to bulk disorder) graphene nanoribbon. However, the spin-polarized transport shows a completely contradicting behavior. Further, the structural symmetries are shown to have an important role in the spintronic properties of the nanoribbons. Moreover, the edge-disorder scenario (disorder selectively placed at the edges) seems to hold promise for the spin-filter and switching device applications.