Controlled engineering of spin-polarized transport properties in a zigzag graphene nanojunction

¹ Department of Physics, Indian Institute of Technology Guwahati - Guwahati-781039, Assam, India
² Physics and Applied Mathematics Unit, Indian Statistical Institute - 203 Barrackpore Trunk Road, Kolkata-700 108, India

Received: 7 May 2018
Accepted: 11 October 2018

Abstract

We investigate a novel way to manipulate the spin-polarized transmission in a two-terminal zigzag graphene nanoribbon in the presence of the Rashba spin-orbit (SO) interaction with a circular-shaped cavity engraved into it. A usual technique to control the spin-polarized transport behaviour of a nanoribbon can be achieved by tuning the strength of the SO coupling, while we show that an efficient engineering of the spin-polarized transport properties can also be done via cavities of different radii engraved in the nanoribbon. Simplicity of the technique in creating such cavities in the experiments renders an additional handle to explore transport properties as a function of the location of the cavity in the nanoribbon. Further, a systematic assessment of the interplay of the Rashba interaction and the dimensions of the nanoribbon is presented. These results should provide useful input to the spintronic behaviour of such devices. In addition to the spin polarization, we have also included an interesting discussion on the charge transmission properties of the nanoribbon, where, in the absence of any SO interaction a metal-insulator transition induced by the presence of a cavity is observed.