Electronic Devices Based on Two-Dimensional Quantum Materials

Abstract

One of the central problems in graphene spintronics is the efficient injection and detection of spins in mesoscopic devices. To date, most of the studies in graphene spin devices use spin-sensitive contacts of Cobalt for injection and detection. However, due to its magnetic properties, Cobalt is prone to form magnetic domains and inhomogeneities, which makes it hard to control its magnetization orientation. This memoir presents a novel approach for spin injection and detection in graphene by material engineering of the ferromagnetic contacts. We have fabricated spin injector/detector contacts of a bilayer of Cobalt and Permalloy (NiFe). Our results demonstrate that Permalloy softens the magnetization reversal of the Cobalt/Permalloy bilayer while the insertion of a very thin layer of the Cobalt layer is essential for efficient spin injection/detection into graphene