We study the microscopic origin of magnetism in suspended and dielectrically embedded CrI_(3)monolayer by down-folding minimal generalized Hubbard models from ab initio calculations using the constrained random phase ...We study the microscopic origin of magnetism in suspended and dielectrically embedded CrI_(3)monolayer by down-folding minimal generalized Hubbard models from ab initio calculations using the constrained random phase approximation.These models are capable of describing the formation of localized magnetic moments in CrI_(3)and of reproducing electronic properties of direct ab initio calculations.Utilizing the magnet force theorem,we find a multi-orbital super-exchange mechanism as the origin of magnetism in CrI_(3)resulting from an interplay between ferro-and anti-ferromagnetic Cr-Cr d coupling channels,which is decisively affected by the ligand p orbitals.We show how environmental screening,such as resulting from encapsulation with hexagonal boron nitride,affects the Coulomb interaction in the film and how this controls its magnetic properties.Driven by a non-monotonic interplay between nearest and next-nearest neighbor exchange interactions we find the magnon dispersion and the Curie temperature to be non-trivially affected by the environmental screening.展开更多
基金We thank M.Kaltak for sharing his cRPA implementation with us.M.I.K.acknowledges support by European Research Council via Synergy Grant 854843—FASTCORRD.S.thanks financial support from EU through the MSCA project Nr.796795 SOT-2DvdW+1 种基金ANR acknowledges partial support from the Russian Science Foundation,Grant No.21-72-10136Part of this work was carried out on the Dutch national e-infrastructure with the support of SURF Cooperative.
文摘We study the microscopic origin of magnetism in suspended and dielectrically embedded CrI_(3)monolayer by down-folding minimal generalized Hubbard models from ab initio calculations using the constrained random phase approximation.These models are capable of describing the formation of localized magnetic moments in CrI_(3)and of reproducing electronic properties of direct ab initio calculations.Utilizing the magnet force theorem,we find a multi-orbital super-exchange mechanism as the origin of magnetism in CrI_(3)resulting from an interplay between ferro-and anti-ferromagnetic Cr-Cr d coupling channels,which is decisively affected by the ligand p orbitals.We show how environmental screening,such as resulting from encapsulation with hexagonal boron nitride,affects the Coulomb interaction in the film and how this controls its magnetic properties.Driven by a non-monotonic interplay between nearest and next-nearest neighbor exchange interactions we find the magnon dispersion and the Curie temperature to be non-trivially affected by the environmental screening.
