Depinning behaviors of magnetic domain wall in ferromagnetic nanowires under magnetic thermal noise

Abstract

In order to observe the influence of the magnetic thermal noise on the magnetic domain wall dynamics in ferromagnetic nanowires, we investigated the pining and the depinning behaviors of the magnetic domain wall in the notched ferromagnetic nanowire under different temperature conditions by means of micromagnetic simulations. By the external magnetic field driving, we observed the pinning and the depinning behaviors of the domain wall in the notched ferromagnetic nanowire. Without the magnetic thermal noise <italic>T</italic>=0 K), due to the constraint of U-type or W-type energy potential wells in the ferromagnetic notch, the magnetic domain wall pinning state and depinning behaviors were affected. In the condition of magnetic thermal noise (<italic>T</italic> ≠ 0 K), the influence of the magnetic thermal noise on the magnetic potential well was obviously increased with the rise of temperature, however the dynamic properties of the domain wall in the ferromagnetic nanowire was still kept. The results mean that dynamic behaviors of the magnetic domain wall are not effectively controlled by the geometry of the ferromagnetic nanowire under the magnetic thermal noise condition.