Chiral Dependence of Vortex Domain Wall Structure in a Stepped Magnetic Nanowire

Abstract

Herein, vortex domain wall (VDW) with anticlockwise chirality (AVDW) and clockwise vortex domain wall (CVDW) with tail‐to‐tail magnetization configuration is studied using micromagnetic simulation. The VDW dynamics and the pinning potential are investigated in a new proposed device with a stepped area of length (l) and depth (d). Spin‐transfer torque is used to drive the domain wall (DW), which could act on the DW motion and stability required for facilitating the future design of the current‐induced DW motion devices. It is found that the VDW structural stability has a high dependence on the geometry of the stepped area (length l and depth d) and VDW chirality. The simulation results show that AVDW has higher structural stability than CVDW at the stepped area. In addition, the stepped nanowire geometries contribute to VDW trapping with a high potential barrier and high structural stability. Furthermore, the VDW speed increases with increasing d to reach 350 m s−1, and no apparent influence can be observed by changing l . All these findings could help in developing future storage memory with low power consumption, high speed, high DW stability, and large storage density.

Chirality‐Dependent Dynamics and Pinning of Transverse Domain Wall in Constricted Nanowires

“…[ 24–29 ] However, the pinning effect can be irregular due to notch size and shape variations. [ 30–34 ] In magnetic nanodevices, different DW structures, such as vortex walls or transverse walls, can be observed which leads to a difference in their dynamics and pinning strength. The vortex‐type walls exhibit different behaviors depending on their chirality and polarity during their motion.…”