Strongly Enhanced Lifetime of Higher-Order Bimerons and Antibimerons.

Magnetic bimerons, similar to skyrmions, are topologically nontrivial spin textures characterized by topological charge Q. Most studies so far have focused on low-Q solitons (|Q| ≤ 1), such as skyrmions, bimerons, and vortices. Here, we present the first calculations of the lifetimes of ring-like high-Q bimerons and demonstrate that they are fundamentally more stable than high-Q skyrmions over a wide range of temperature. To obtain realistic results, our chosen system is an experimentally feasible van der Waals interface, Fe3GeTe2/Cr2Ge2Te6. We show that the lifetimes of high-Q (anti)bimerons can exceed the lifetimes of those with |Q| = 1 by 3 orders of magnitude. Remarkably, this trend remains valid even when extrapolated to room temperature (RT) because the lifetimes are dominated by entropy rather than energy barriers. This contrasts with high-Q skyrmions, whose lifetimes fall with |Q| near RT. We attribute this fundamental difference between skyrmions and bimerons to their distinct magnetic texture symmetries, which lead to different entropy-dominated lifetimes.