Dzyaloshinskii-Moriya Interaction of Cr₂O₂ClI Janus Monolayer: A First-Principles Calculation

The Dzyaloshinskii-Moriya interactions (DMIs) of Cr2O2ClI Janus monolayer are investigated using the first-principles calculations. There are three DMI mechanisms (namely, the Half-Fert-Levy mechanism, the Fert-Levy mechanism, and the Rashba mechanism) in Cr2O2ClI Janus monolayer. The Half-Fert-Levy mechanism, by which the I atoms enhance the spin orbit coupling interaction on the type-I Cr atoms but have no such effect on the type-II Cr atoms, contributes to the y-component of the DMI vector between two nearest-neighbor Cr atoms. Originating from the strong spin orbit coupling interaction of the I atoms, the Fert-Levy mechanism results in a significant DMI vector via the Cr-I-Cr exchange path between two type-I next-nearest-neighbor Cr atoms. Induced by the intrinsic electric field of the Janus structure, the Rashba mechanism results in nonzero in-plane components of the DMI vectors. This work provides the first-principles calculations of the DMIs of Cr2O2ClI Janus monolayer and reveals insight into the physics behind the calculated DMIs, which promote the understanding of the complicated DMIs due to multiple mechanisms in 2D magnetic Janus monolayers.