The interface of graphene with ferromagnets is highly relevant for spintronics, because graphene on Co(0001) shows a largely intact Dirac cone and strong hybridization with Co 3d states breaking the sublattice symmetry that had been considered mutually exclusive. Here we show by spin-and angle-resolved photoemission that the Dirac cone and Dirac point are also highly spin polarized (similar to -25%), which reinforces the puzzling issue of a strong graphene-substrate interaction. The problem is solved by our ab initio calculations which show that (i) the upper and lower halves of the Dirac cone belong to different sublattices and (ii) one half is spin polarized by spin-dependent hybridization because it is situated at the edge of a minority-spin band gap of the Co substrate.
Highly spin-polarized Dirac fermions at the graphene/Co interface
Carbone C;
2015
Abstract
The interface of graphene with ferromagnets is highly relevant for spintronics, because graphene on Co(0001) shows a largely intact Dirac cone and strong hybridization with Co 3d states breaking the sublattice symmetry that had been considered mutually exclusive. Here we show by spin-and angle-resolved photoemission that the Dirac cone and Dirac point are also highly spin polarized (similar to -25%), which reinforces the puzzling issue of a strong graphene-substrate interaction. The problem is solved by our ab initio calculations which show that (i) the upper and lower halves of the Dirac cone belong to different sublattices and (ii) one half is spin polarized by spin-dependent hybridization because it is situated at the edge of a minority-spin band gap of the Co substrate.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
