Finsler geometry modeling and Monte Carlo study of skyrmion shape deformation by uniaxial stress

Article

关键词: REAL-SPACE OBSERVATION;    DENSITY-WAVE PHASE;    LATTICE;    CRYSTALS;    STATE;   

DOI  :  10.1103/PhysRevB.104.024402

来源: SCIE

【 摘 要 】

Skyrmions in chiral magnetic materials are topologically stable and energetically balanced spin configurations appearing under the presence of ferromagnetic interaction (FMI) and Dzyaloshinskii-Moriya interaction (DMI). Much of the current interest has focused on the effects of magnetoelastic coupling on these interactions under mechanical stimuli, such as uniaxial stresses for future applications in spintronics devices. Recent studies suggest that skyrmion shape deformations in thin films are attributed to an anisotropy in the coefficient of DMI, such that D-x not equal D-y, which makes the ratio lambda/D anistropic, where the coefficient of FMI lambda is isotropic. It is also possible that lambda(x) not equal lambda(y) while D is isotropic for lambda/D to be anisotropic. In this paper, we study this problem using a modeling technique constructed based on Finsler geometry (FG). Two possible FG models are examined: In the first (second) model, the FG modeling prescription is applied to the FMI (DMI) Hamiltonian. We find that these two different FG models' results are consistent with the reported experimental data for skyrmion deformation. We also study responses of helical spin orders under lattice deformations corresponding to uniaxial extension/compression and find a clear difference between these two models in the stripe phase, elucidating which interaction of FMI and DMI is deformed to be anisotropic by uniaxial stresses.

【 授权许可】

Free