Topological Defect Mediated Helical Phase Reorientation by Uniaxial Stress

TL;DR

This study demonstrates how uniaxial stress can reorient helical magnetic domains via defect-mediated processes, revealing parallels with metal plasticity and highlighting strain-induced anisotropic interactions for magnetic control.

Contribution

It uncovers the mechanisms of strain-induced magnetic reorientation mediated by defects, combining experimental observations with simulations to advance understanding of magneto-mechanical coupling.

Findings

Helical domain reorientation depends on stress angle.

Magnetic defects facilitate reorientation through defect dynamics.

Strain-induced anisotropic Dzyaloshinskii-Moriya interaction is significant.

Abstract

Strain engineering enables precise, energy-efficient control of nanoscale magnetism. However, unlike well-studied strain-dislocation interactions in mechanical deformation, the spatial evolution of strain-induced spin rearrangement remains poorly understood. Using \emph{in situ} Lorentz transmission electron microscopy, we manipulate and observe helical domain reorientation under quantitatively applied uniaxial tensile stress. Our findings reveal striking similarity to plastic deformation in metals, where the critical stress for propagation vector (\emph{\textbf{Q}}) reorientation depends on its angle with the stress direction. Magnetic defects mediate reorientation via "break-and-reconnect" or "dislocation gliding-annihilation" processes. Simulations confirm that strain-induced anisotropic Dzyaloshinskii-Moriya interaction may play a key role. These insights advance strain-driven magnetism and offer a promising route for energy-efficient magnetic nanophase control in next-generation information technology.