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

Abstract

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 magneto-elastic 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 $D_x\ne D_y$, which makes the ratio $\lambda /D$ anistropic, where the coefficient of FMI $\lambda$ is isotropic. It is also possible that ${\lambda }_x\ne {\lambda }_y$ while $D$ is isotropic for $\lambda /D$ to be anisotropic. In this paper, we study this problem using a new 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.

42 pages, 23 figures

References in corpus (9)

• Advances in the Physics of Magnetic Skyrmions and Perspective for Technology
• Spontaneous Skyrmion Ground States in Magnetic Metals
• Theory of current-driven motion of Skyrmions and spirals in helical magnets
• A reversible conversion between a skyrmion and a domain-wall pair in junction geometry
• Fluctuation-induced first-order phase transition in Dzyaloshinskii-Moriya helimagnets
• Fractional antiferromagnetic skyrmion lattice induced by anisotropic couplings
• Giant generic topological Hall resistivity of MnSi under pressure
• Helical and skyrmion lattice phases in three-dimensional chiral magnets: Effect of anisotropic interactions
• Electromechanical properties of ferroelectric polymers: Finsler geometry modeling and a Monte Carlo study

Cited by in corpus (3)

• Stability of Skyrmion Crystal Phase in Centrosymmetric Distorted Triangular-Lattice Antiferromagnets
• Monte Carlo studies of skyrmion stabilization under geometric confinement and uniaxial strain
• Enhanced skyrmion metastability under applied strain in FeGe