Birth, growth and death of an antivortex during the propagation of a transverse domain wall in magnetic nanostrips

Abstract

Antivortex birth, growth and death due to the propagation of a transverse domain wall (DW) in magnetic nanostrips are observed and analyzed. Antivortex formation is an intrinsic process of a strawberry-like transverse DW originated from magnetostatic interaction. Under an external magnetic field, DW in a wider width region tends to move faster than that of a narrower part. This speed mismatch tilts and elongates DW centre line. An antivortex is periodically born near the tail of the DW centre line. The antivortex either moves along the centre line and dies on the other side of the strip, or grows to its maximum size, detaches itself from the DW, and vanishes eventually. The former route reverses the polarity of DW while the later keeps the DW polarity unchanged. The evolution of the DW structures is analyzed using winding numbers assigned to each topological defects. The phase diagram in the field-width plane is obtained and discussed.

Skyrmion Creation and Manipulation by Nano-Second Current Pulses

“…Generally speaking, transformation between two spin textures 17 18 in a system can only occur when both textures are stable or metastable. This is also the case for skyrmion creation in spin valves.…”

Field-driven side-by-side magnetic domain wall dynamics in ferromagnetic nanostrips

“…On one hand, most analytical models are one-dimensional (1D) models that are only applicable for very thin and narrow lines or strips, or very large bulk systems which are uniform in the other two dimensions [4,19,20]. For generic systems, especially magnetic strips whose width is much larger than the domain wall width, the 1D model fails due to the variation in the width direction [21][22][23]. On the other hand, most studies focus on in-plane head-to-head (or tail-to-tail) domain walls [15,16] or perpendicular magnetic anisotropy (PMA) domain walls [24][25][26].…”

“…There have been a lot of studies on the field-driven dynamics and internal structures of head-to-head (tailto-tail) domain walls and PMA domain walls [21][22][23]. It is well known that in a biaxial system with an easy anisotropy axis and a hard anisotropy axis, the domain wall moves under the longitudinal magnetic field in a rigid-body manner and the velocity increases with the field strength.…”

Propagation of Spin Waves in a 2D Vortex Network

“…The principle of constructing a 1D CW-ACW-CW vortex chain has been demonstrated in the Supporting Information (Sections 5−7), suggesting that the topological defects are conserved during the process. 53 The experimental procedure of constructing a CW-ACW-CW vortex chain in the top Ni 80 Fe 20 nanostrip has been provided in the Supporting Information (Section 8). Notably, the notch of the Ni 80 Fe 20 nanostrip can facilitate the formation of a CW-ACW-CW chain through the generation of an ACW core 54 (see Supporting Information, Section 9).…”

“…Two notches are introduced near the center of the top and bottom Ni 80 Fe 20 nanostrips. The principle of constructing a 1D CW-ACW-CW vortex chain has been demonstrated in the Supporting Information (Sections 5–7), suggesting that the topological defects are conserved during the process . The experimental procedure of constructing a CW-ACW-CW vortex chain in the top Ni 80 Fe 20 nanostrip has been provided in the Supporting Information (Section 8).…”