Work

Interplay between Kitaev interaction and single ion anisotropy in ferromagnetic CrI3 and CrGeTe3 monolayers

Year: 2018

Type: article

Abstract: Magnetic anisotropy is crucially important for the stabilization of two-dimensional (2D) magnetism, which is rare in nature but highly desirable in spintronics and for advancing fundamental knowledge. Recent works on CrI 3 and CrGeTe 3 monolayers not only led to observations of the long-time-sought 2D ferromagnetism, but also revealed distinct magnetic anisotropy in the two systems, namely Ising behavior for CrI 3 versus Heisenberg behavior for CrGeTe 3 . Such magnetic difference strongly contrasts with structural and electronic similarities of these two materials, and understanding it at a microscopic scale should be of large benefits. Here, first-principles calculations are performed and analyzed to develop a simple Hamiltonian, to investigate magnetic anisotropy of CrI 3 and CrGeTe 3 monolayers. The anisotropic exchange coupling in both systems is surprisingly determined to be of Kitaev-type. Moreover, the interplay between this Kitaev interaction and single ion anisotropy (SIA) is found to naturally explain the different magnetic behaviors of CrI 3 and CrGeTe 3 . Finally, both the Kitaev interaction and SIA are further found to be induced by spin–orbit coupling of the heavy ligands (I of CrI 3 or Te of CrGeTe 3 ) rather than the commonly believed 3 d magnetic Cr ions.

Source: npj Computational Materials

DOI: 10.1038/s41524-018-0115-6

Authors: Changsong Xu, Junsheng Feng, Hongjun Xiang, Laurent Bellaiche

Institutions: University of Arkansas at Fayetteville, Hefei Normal University, Fudan University, State Key Laboratory of Surface Physics, Collaborative Innovation Center of Advanced Microstructures

Language: English

Topic: 2D Materials and Applications

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $3,490