R&D: Spontaneous Skyrmionic Lattice From Anisotropic Symmetric Exchange in Ni-Halide Monolayer

Nature Communications has published an article written by Danila Amoroso, Paolo Barone, and Silvia Picozzi, Consiglio Nazionale delle Ricerche CNR-SPIN, c/o Università degli Studi ‘G. D’Annunzio’, 66100, Chieti, Italy.

Abstract: “Topological spin structures, such as magnetic skyrmions, hold great promises for data storage applications, thanks to their inherent stability. In most cases, skyrmions are stabilized by magnetic fields in non-centrosymmetric systems displaying the chiral Dzyaloshinskii-Moriya exchange interaction, while spontaneous skyrmion lattices have been reported in centrosymmetric itinerant magnets with long-range interactions. Here, a spontaneous anti-biskyrmion lattice with unique topology and chirality is predicted in the monolayer of a semiconducting and centrosymmetric metal halide, NiI₂. Our first-principles and Monte Carlo simulations reveal that the anisotropies of the short-range symmetric exchange, when combined with magnetic frustration, can lead to an emergent chiral interaction that is responsible for the predicted topological spin structures. The proposed mechanism finds a prototypical manifestation in two-dimensional magnets, thus broadening the class of materials that can host spontaneous skyrmionic states.“