Diameter-independent skyrmion Hall angle in the plastic flow regime observed in chiral magnetic multilayers

TL;DR

This study reveals that in the plastic flow regime, the skyrmion Hall angle remains constant regardless of skyrmion size, challenging previous beliefs about its diameter dependence and highlighting the role of local energy landscapes.

Contribution

The paper demonstrates that in the plastic flow regime, the skyrmion Hall angle is independent of skyrmion diameter, emphasizing the influence of local energy landscapes over size effects.

Findings

Skyrmion Hall angle is diameter-independent in the plastic flow regime.

Average skyrmion Hall angle measured at 9 degrees at 6 m/s.

Dynamics dominated by local energy landscape such as defects.

Abstract

Magnetic skyrmions are topologically non-trivial nanoscale objects. Their topology, which originates in their chiral domain wall winding, governs their unique response to a motion-inducing force. When subjected to an electrical current, the chiral winding of the spin texture leads to a deflection of the skyrmion trajectory, characterized by an angle with respect to the applied force direction. This skyrmion Hall angle was believed to be skyrmion diameter-dependent. In contrast, our experimental study finds that within the plastic flow regime the skyrmion Hall angle is diameter-independent. At an average velocity of 6 $\pm$ 1 m/s the average skyrmion Hall angle was measured to be 9{\deg} $\pm$ 2{\deg}. In fact, in the plastic flow regime, the skyrmion dynamics is dominated by the local energy landscape such as materials defects and the local magnetic configuration.