Jugovac, M.; Cojocariu, I.; Sánchez-Barriga, J.; Gargiani, P.; Valvidares, M.; Feyer, V.; Blügel, S.; Bihlmayer, G.; Perna, P.: Inducing Single Spin-Polarized Flat Bands in Monolayer Graphene. Advanced Materials 35 (2023), p. 2301441/1-8
10.1002/adma.202301441
Open Access Version
Abstract:
Due to the fundamental and technological implications in driving the appearance of non-trivial, exotic topological spin textures and emerging symmetry-broken phases, flat electronic bands in 2D materials, including graphene, are nowadays a relevant topic in the field of spintronics. Here, via europium doping, single spin-polarized bands are generated in monolayer graphene supported by the Co(0001) surface. The doping is controlled by Eu positioning, allowing for the formation of a k-valley localized single spin-polarized low-dispersive parabolic band close to the Fermi energy when Eu is on top, and of a π* flat band with single spin character when Eu is intercalated underneath graphene. In the latter case, Eu also induces a bandgap opening at the Dirac point while the Eu 4f states act as a spin filter, splitting the π band into two spin-polarized branches. The generation of flat bands with single spin character, as revealed by the spin- and angle-resolved photoemission spectroscopy (ARPES) experiments, complemented by density functional theory (DFT) calculations, opens up new pathways toward the realization of spintronic devices exploiting such novel exotic electronic and magnetic states.