Field-Selected Topological Buffering in a Disordered Skyrmion Crystal
arXiv:2607.28458
The paper uses large‑scale simulations to show that a magnetic field can separate the loss of crystalline order from the loss of topological charge in disordered skyrmion crystals, creating a “topological buffer” where skyrmion textures remain robust despite structural disorder.
Abstract
Quenched disorder can disrupt crystalline order without immediately destroying the topology of its constituent textures, but the relation between these processes in skyrmion crystals remains unclear. Using large-scale simulations of a triangular-lattice chiral magnet with random DM interactions, we show that the magnetic field selects between two disordering routes. At high fields, global translational coherence is lost at a weak-disorder scale, while sixfold bond-orientational order survives to a larger disorder strength and the total topological charge remains nearly locked up to a substantially larger scale. The resulting interval defines a topological buffer containing a Bragg-glass- like skyrmion regime followed by a skyrmion-glass regime. Finite-size scaling, spatial correlations, defect statistics, and spin autocorrelations support their distinct structural and glassy character. At lower fields, bond-orientational disordering nearly coincides with topological reconstruction, eliminating the skyrmion-glass window and contracting the buffer. These results identify the magnetic field as a control knob for separating crystalline disordering from topological-charge loss and establish topological buffering as a mechanism by which topological textures can remain robust in structurally disordered media.
6 pages, 3 figures