d0 Magnetic Skyrmions in Two-Dimensional Lattice

Abstract

Magnetic skyrmions are topologically protected chiral spin textures that hold great promise for information storage and processing. The current research efforts on magnetic skyrmions are exclusively based on d-orbital magnetism, which restricts their existence in a narrow window of temperature-external magnetic field (T-B) phase diagram. Herein, employing first-principles and Monte-Carlo simulations, the work reports the identification of d⁰ magnetic skyrmions in 2D lattice of Tl₂NO₂. Arising from inversion asymmetry and strong spin-orbit coupling compensated by ligand of heavy element, large Dzyaloshinskii–Moriya interaction is obtained in monolayer Tl₂NO₂. This, competed with p-orbital exchange interaction, leads to the d⁰ skyrmion physics under external magnetic field. Importantly, different from d-orbital topological magnetism, the d⁰ magnetic skyrmions can be stabilized in a wide window of T-B phase diagram. The underlying physics is related to the small magnetic moment and delocalization character of d⁰ magnetism. Furthermore, the work also demonstrates that the d⁰ magnetic skyrmions are strongly coupled with ferroelectricity. These findings open a new direction for magnetic skyrmion research.