Curvature-induced effects in domain wall dynamics in stripes with spatially varying cross section

Here we study both analytically and numerically the influence of curvature and cross section deformation effects on the motion of a domain wall in curved stripes which corresponds to geometry of recent experiments [1]. We base our study on a phenomenological Landau-Lifshitz-Gilbert equations using collective variable approach based on a q-Φ model. We show that (i) curvature and nonzero gradient of cross-section deformation result in a modification of a ground state and can be interpreted as an effective magnetic field. (ii) The presence of a nonzero gradient of cross section deformation also results in a pinning potential for domain walls in addition to the curvature-induced potential [2]. In effective equations of motions the spatially varying cross section and curvature appear as a driving forces which can suppress or reinforce the action of each other. The eigenfrequency oscillations of domain wall in vicinity of the pinning potential is obtained as a function of curvature and cross section deformation and their gradients. All analytical predictions are well confirmed by full scale micromagnetic simulations.

1. L. Skoric et al, ACS Nano 16, 8860 (2022).

2. K. V. Yershov et al, PRB 92, 104412 (2015).