Spin transport and Hanle effect in silicon nanowires using graphene tunnel barriers

• Published in: Nature communications Vol. 6; no. 1; p. 7541
• Main Authors: van 't Erve, O M J, Friedman, A L, Li, C H, Robinson, J T, Connell, J, Lauhon, L J, Jonker, B T
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 19.06.2015
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms8541

Spin-based devices offer non-volatile, scalable, low power and reprogrammable functionality for emerging device technologies. Here we fabricate nanoscale spintronic devices with ferromagnetic metal/single-layer graphene tunnel barriers used to generate spin accumulation and spin currents in a silicon nanowire transport channel. We report the first observation of spin precession via the Hanle effect in both local three-terminal and non-local spin-valve geometries, providing a direct measure of spin lifetimes and confirmation of spin accumulation and pure spin transport. The use of graphene as the tunnel barrier provides a low-resistance area product contact and clean magnetic switching characteristics, because it smoothly bridges the nanowire and minimizes complicated magnetic domains that otherwise compromise the magnetic behaviour. Utilizing intrinsic two-dimensional layers such as graphene or hexagonal boron nitride as tunnel contacts on nanowires offers many advantages over conventional materials deposited by vapour deposition, enabling a path to highly scaled electronic and spintronic devices.