Skyrmion formation in Ni-based Janus dihalide monolayers: Interplay between magnetic frustration and Dzyaloshinskii-Moriya interaction

We present a comprehensive theory of the magnetic phases in monolayer nickel-based Janus dihalides (NiIBr, NiICl, NiBrCl) through a combination of first-principles calculations and atomistic simulations. Phonon band structure calculations and finite-temperature molecular dynamics simulations show that Ni-dihalide Janus monolayers are stable. The parameters of the interacting spin Hamiltonian extracted from ab initio calculations show that nickel-dihalide Janus monolayers exhibit varying degrees of magnetic frustration together with a large Dzyaloshinskii-Moriya interaction due to their inherent inversion symmetry breaking. The atomistic simulations reveal a delicate interplay between these two competing magnetic interactions in giving rise to skyrmion formation.

Automated summary

We propose a comprehensive theory of magnetic phases in monolayer nickel-based Janus dihalides (NiIBr, NiICl, NiBrCl) using first-principles calculations and atomistic simulations. Phonon band structure calculations and finite-temperature molecular dynamics simulations demonstrate the stability of Ni-dihalide Janus monolayers. The parameters of the interacting spin Hamiltonian obtained from ab initio calculations show various degrees of magnetic frustration and a large Dzyaloshinskii-Moriya interaction due to inversion symmetry breaking in nickel-dihalide Janus monolayers. Atomistic simulations reveal the delicate interplay between these competing magnetic interactions, leading to the formation of skyrmions.