Thermally driven topology in frustrated systems

Article

关键词: TOTAL-ENERGY CALCULATIONS;    MAGNETIC-PROPERTIES;    SKYRMION LATTICE;    MNBI;    STATES;   

DOI  :  10.1103/PhysRevB.99.104431

来源: SCIE

【 摘 要 】

Topological spin textures, such as magnetic skyrmions, have been extensively discussed in magnetic materials with broken inversion symmetry. Most of these textures are stable at low temperatures and form long-range orders. However, the topological nature of these textures, characterized by the index called topological charge, is actually persistent at elevated temperatures. In this work, the topological charge of a two-dimensional frustrated spin model with the Dzyaloshinskii-Moriya (DM) interaction was calculated by the Monte Carlo simulations. At finite temperatures, nontrivial topology driven by thermal fluctuation was discovered in a spin-disordered phase. This thermally driven topology is the dominant topology at low magnetic fields. The magnitude of topological charge is quadratic in the DM interaction and linear in the external magnetic field or uniaxial magnetic anisotropy. We also propose a real frustrated system, the Mn-Bi monolayer film, with large DM interaction to enable such thermally driven topology. A full phase diagram of this system has been explored.

【 授权许可】

Free