Phys. Rev. B 111, 174106 (2025)

Antiskyrmions, as topological quasiparticles, hold significant promise for spintronics and nanoscale data storage applications. Using molecular dynamics simulations based on effective Hamiltonians, we investigated the thermal stability of antiskyrmion nanodomains in rhombohedral barium titanate. At 1 K, antiskyrmions with a topological charge of −2 were found to be the most stable nanodomain state across all diameters examined by us. In our systematic study, the most robust antiskyrmion was found to have a diameter of 4 nm, maintaining its original size, shape, and topological charge up to the characteristic temperature 𝑇* ≈ 85 K. Domains with diameters between 2.8 and approximately 4.5 nm exhibited fragmentation into six topological defects, termed quarks, each carrying a fractional skyrmion charge of −1/3. For domains larger than 4.5 nm, each topological quark split into two prequarks, each with a charge of −1/6. These larger nanodomains demonstrated increased mobility and a growing tendency for shape and skyrmion charge fluctuations. Above the 𝑇* temperature, all larger nanodomains gradually shrank to a diameter of about 4 nm before collapsing into a single-domain state. These findings reveal the relatively high stability of antiskyrmions over a broad temperature range, even in the absence of a stabilizing bias field, and emphasize the pivotal role of topological quark dynamics. This establishes barium titanate as a key platform for exploring and applying topological phenomena.