Spin-dependent $π$$π^{\ast}$ gap in graphene on a magnetic substrate

P. M. Sheverdyaeva, G. Bihlmayer, E. Cappelluti, D. Pacilé, F. Mazzola, N. Atodiresei, M. Jugovac, I. Grimaldi, G. Contini, A. K. Kundu, I. Vobornik, J. Fujii, P. Moras, C. Carbone, L. Ferrari

Published 2024-04-27Version 1

We present a detailed analysis of the electronic properties of graphene/Eu/Ni(111). By using angle and spin-resolved photoemission spectroscopy and ab initio calculations, we show that the Eu-intercalation of graphene/Ni(111) restores the nearly freestanding dispersion of the $\pi\pi^\ast$ Dirac cones at the K point with an additional lifting of the spin degeneracy due to the mixing of graphene and Eu states. The interaction with the magnetic substrate results in a large spin-dependent gap in the Dirac cones with a topological nature characterized by a large Berry curvature, and a spin-polarized van Hove singularity, whose closeness to the Fermi level gives rise to a polaronic band.