Strain-tunable chiral spin textures via magnetic anisotropy in two-dimensional Janus RuICl monolayer

Dzyaloshinskii–Moriya interaction (DMI) and magnetic anisotropy energy are widely recognized as the primary factors responsible for the formation of chiral magnetic structures. Here, using first-principles calculations and spin dynamic simulations, we demonstrate that the RuICl Janus structure exhibits a high Curie temperature (Tc) of 319 K, significant DMI, perpendicular magnetic anisotropy (PMA), and spontaneous polarization. Interestingly, as tensile strain is progressively applied, RuICl transforms from the initial PMA to in-plane magnetic anisotropy, which leads to the evolution of spin texture through a sequence of transitions, progressing from a single-domain state to stripe domains, followed by a mixed state of domain walls and skyrmions, and ultimately transitioning to in-plane stripe domains. Furthermore, the synergistic application of tensile strain and an external magnetic field effectively induces skyrmions states. Spin texture modulation strongly depends on the magnetic field orientation. In addition, tensile strain significantly modulates the vertical polarization in the Janus RuICl monolayer. Our findings highlight the potential of the RuICl monolayer as a promising candidate for spintronic devices based on topological spin textures.