MICROMAGNETIC STUDY OF TEMPERATURE-DEPENDENT DOMAIN WALL DEPINNING BEHAVIOR IN FERROMAGNETIC NANOWIRES

Abstract

Magnetic devices based on a magnetic domain wall (DW) motion have been attracting huge interests due to the possibility in realization of a future magnetic storage and a novel logic device [1-3]. Recently, a study of DW motion controlled by a spin transfer torque in the ferromagnetic nanowire has been intensively investigated [4-7]. In particular, when a DW is driven by the spin transfer torque generated by the spin-polarized current, a thermal noise effect cannot be avoided due to the Joule heating. It has been known that even the operation speed of magnetic devices based on the DW motion will be affected by the thermal noise effect [8]. Therefore, understanding of the influence of the thermal noise effect on the DW dynamic behavior in ferromagnetic nanowires is essential for the realization of future magnetic devices. In this paper, we present the depinning behavior of the DW initially positioned at the notch of the notched ferromagnetic nanowire at a finite temperature by means of micromagnetic simulation based on the LandauLifshitz-Gilbert equation with addition of the thermal noise term.