Spin negative differential resistance in edge doped zigzag graphene nanoribbons

• Published in: Carbon (New York) 2014-03, Vol.68, p.406-412
• Main Authors: Jiang, Chao, Wang, Xue-Feng, Zhai, Ming-Xing
• Format: Article
• Language: English
• Subjects: Aluminum; Bias; Carbon; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Density functional theory; Electric potential; Electron states; Electronic transport in condensed matter; Exact sciences and technology; Fullerenes and related materials; diamonds, graphite; Graphene; Materials science; Methods of electronic structure calculations; Nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals; Nanostructure; Physics; Specific materials; Spin polarized transport; Structure of solids and liquids; crystallography; Voltage
• ISSN: 0008-6223; 1873-3891
• DOI: 10.1016/j.carbon.2013.11.017

The nonlinear spin-dependent transport properties in zigzag graphene nanoribbons (ZGNRs) edge doped by an atom of group III and V elements are studied systematically using density functional theory combined with non-equilibrium Green’s functions. The dopant type, acceptor or donor, and the geometrical symmetry, odd or even, are found critical in determining the spin polarization of the current and the current–voltage characteristics. For ZGNRs substitutionally doped on the lower-side edge, the down (up) spin current dominates in odd-(even-) width ZGNRs under a bias voltage around 1V. Remarkably, in even-width ZGNRs, doped by group III elements (B and Al), negative differential resistance (NDR) occurs only for down spins. The bias range of the spin NDR increases with the width of ZGNRs. The clear spin NDR is not observed in any odd-width ZGNRs nor in even-width ZGNRs doped by group V elements (N and P). This peculiar spin NDR of edge doped ZGNRs suggests potential applications in spintronics.