Effect of a local temperature region on the suppression of walker breakdown in a permalloy nanowire

Abstract

Magnetic domain walls are potential data carriers in future spintronic devices and the application based on current-driven domain wall (DW) motion primarily relies on the effective control of the moving velocity of the DW and its structural stability. In this work, the propagation of the magnetic domain walls along a ferromagnetic nanowire with a localized temperature region is studied by micromagnetic simulation. The research indicates that the local temperature field can suppress the generation of Walker breakdown (WB) and make the transverse domain wall (TDW) move to a longer distance with a stable structure. The degree of suppression is the result of the joint influence of temperature difference (ΔT) and temperature region width (d). When both of the ΔT and the d are relatively large, the suppression effect is comparatively strong, while either of the ΔT and the d are small, the suppression effect is weak. The results reveal the local temperature field makes the exchange energy in the region reach a very high value rapidly, and the out-of-plane magnetic moment Mz of the DW keeps at a high level, which promotes the high-speed motion of the DW and suppresses the WB by destroying the periodic transition of the DW structure.