Strongly Enhanced Lifetime of Higher-Order Bimerons and Antibimerons.

Zhu, Shiwei; Goerzen, Moritz A; Song, Changsheng; Heinze, Stefan; Li, Dongzhe · Nano Lett · 2026

basic_science · Level V

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Abstract

Magnetic bimerons, similar to skyrmions, are topologically nontrivial spin textures characterized by topological charge <i>Q</i>. Most studies so far have focused on low-<i>Q</i> solitons (|<i>Q</i>| ≤ 1), such as skyrmions, bimerons, and vortices. Here, we present the first calculations of the lifetimes of ring-like high-<i>Q</i> bimerons and demonstrate that they are fundamentally more stable than high-<i>Q</i> skyrmions over a wide range of temperature. To obtain realistic results, our chosen system is an experimentally feasible van der Waals interface, Fe<sub>3</sub>GeTe<sub>2</sub>/Cr<sub>2</sub>Ge<sub>2</sub>Te<sub>6</sub>. We show that the lifetimes of high-<i>Q</i> (anti)bimerons can exceed the lifetimes of those with |<i>Q</i>| = 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-<i>Q</i> skyrmions, whose lifetimes fall with |<i>Q</i>| near RT. We attribute this fundamental difference between skyrmions and bimerons to their distinct magnetic texture symmetries, which lead to different entropy-dominated lifetimes.