Orbital magnetoelectric effect in zigzag nanoribbons of -band systems

Profiles of the spin and orbital angular momentum accumulations induced by a longitudinally applied electric field are explored in nanoribbons of -band systems with a honeycomb lattice. We show that nanoribbons with zigzag borders can exhibit orbital magnetoelectric effects. More specifically, we have found that purely orbital magnetization oriented perpendicularly to the ribbon may be induced in these systems by means of the external electric field when sublattice symmetry is broken. The effect is rather general and may occur in other multiorbital materials.T.G.R. acknowledges funding from Fundação para a Ciência e a Tecnologia and Instituto de Telecomunicações, Grant No. UID/50008/2020 in the framework of the project Sym-Break. T.G.R. thankfully acknowledges the computer resources at MareNostrum and the technical support provided by Barcelona Supercomputing Center (FI-2020-2-0033). L.M.C. acknowledges funding from The Army Research Office under Grant No. W911NF-21-1-0004. ICN2 is funded by the CERCA Programme/Generalitat de Catalunya and supported by the Severo Ochoa Centres of Excellence program, funded by the Spanish Research Agency (Grant No. SEV-2017-0706)