Meron-Like Topological Spin Defects in Monolayer CrCl3

Noncollinear spin textures in low-dimensional magnetic systems have been studied for decades because of their extraordinary properties and promising applications derived from their chirality and topological nature. However, material realizations of topological spin states are still limited. Employing first-principles and Monte Carlo simulations, we propose that monolayer CrCl₃, can be a promising candidate for observing the vortex/antivortex types of topological defects, so-called merons. Beyond the typical bimerons picture, higher-order states which involves more than two merons, are also identified in simulations. By perturbing with external magnetic field, we further show the robustness of these meron pairs and reveal a rich phase space to tune the hybridization between the ferromagnetic order and meron-like defects. The signatures of topological excitations under external magnetic field also provide crucial information for experimental justifications. Our study predicts that two-dimensional magnets with weak spin-orbit coupling can be a promising family for realizing meron-like spin textures.