Thermal driven topology in chiral magnets

Chiral magnets give rise to the anti-symmetric Dzyaloshinskii-Moriya (DM) interaction, which induces topological nontrivial textures such as magnetic skyrmions. The topology is characterized by integer values of the topological charge. In our work[1], we performed the Monte-Carlo calculation of a two-dimensional model of the chiral magnet. A surprising upturn of the topological charge is identified at high fields and high temperatures. This upturn is closely related to thermal fluctuations at the atomic scale, and is explained by a simple physical picture based on triangulation of the lattice. This emergent topology is also explained well by a field-theoretic analysis using CP¹ formalism. It is predicted that this phenomenon can be observed experimentally through the thermal Hall effect. [1] W. T. Hou, J. X. Yu, M. Daly and J. Zang, Phy. Rev. B 96, 140403 (2017).