Absence of Walker breakdown in the dynamics of chiral Neel domain walls driven by in-plane strain gradients

TL;DR

This paper theoretically demonstrates that in-plane strain gradients can drive chiral Neel domain walls efficiently without Walker breakdown, achieving high velocities and stable motion in magnetic systems.

Contribution

It reveals that strain gradients induce steady domain wall motion without turbulent dynamics, a novel mechanism for controlling magnetic domain walls.

Findings

Steady domain wall motion is achieved without Walker breakdown.

Velocities up to 500 m/s are possible with voltage-induced strain.

Strain gradients prevent turbulent dynamics in domain wall motion.

Abstract

We investigate theoretically the motion of chiral N\'eel domain walls in perpendicularly magnetized systems driven by in-plane strain gradients. We show that such strain drives domain walls efficiently towards increasing tensile (compressive) strain for positive (negative) magnetostrictive materials. During their motion a local damping torque that opposes the precessional torque due to the strain gradient arises. This torque prevents the onset of turbulent dynamics, and steady domain wall motion with constant velocity is asymptotically reached for any arbitrary large strain gradient. Withal, velocities in the range of 500 m/s can be obtained using voltage-induced strain under realistic conditions.