Effect of Chiral Damping on the dynamics of chiral domain walls and skyrmions

TL;DR

This paper investigates how chiral damping influences the movement of magnetic domain walls and skyrmions, revealing its competing effects with DMI and its importance for stabilizing skyrmions, through experiments and numerical modeling.

Contribution

It demonstrates the impact of chiral damping on DW and SK dynamics and distinguishes its effects from DMI using in-plane magnetic fields and numerical simulations.

Findings

Chiral damping affects the flow motion of DWs and SKs.

Sign reversal of chiral asymmetry is due to competing effects of DMI and chiral damping.

Non-linear chiral dissipation is crucial for skyrmion stabilization.

Abstract

Friction plays an essential role in most physical processes that we experience in our everyday life. Examples range from our ability to walk or swim, to setting boundaries of speed and fuel efficiency of moving vehicles. In magnetic systems, the displacement of chiral domain walls (DW) and skyrmions (SK) by Spin Orbit Torques (SOT), is also prone to friction. Chiral damping, the dissipative counterpart of the Dzyaloshinskii Moriya Interaction (DMI), plays a central role in these dynamics. Despite experimental observation, and numerous theoretical studies confirming its existence, the influence of chiral damping on DW and SK dynamics has remained elusive due to the difficulty of discriminating from DMI. Here we unveil the effect that chiral damping has on the flow motion of DWs and SKs driven by current and magnetic field. We use a static in-plane field to lift the chiral degeneracy. As the in-plane field is increased, the chiral asymmetry changes sign. When considered separately, neither DMI nor chiral damping can explain the sign reversal of the asymmetry, which we prove to be the result of their competing effects. Finally, numerical modelling unveils the non-linear nature of chiral dissipation and its critical role for the stabilization of moving SKs.