Curvature effects of current-induced domain wall motion in a U-shaped nanowire

摘要

The structural inhomogeneities of the magnetic media substantially affect the domain wall (DW) motion. Pioneer studies have theoretically revealed that the exchange term of the Hamiltonian for curved nanowires includes an effective Dzyaloshinskii-Moriya (DM)-like interaction [1,2]. This interaction depends on the curvature of the wire, so that the curvature variation gives rise to a gradient of the potential energy, which pins the DW at the extreme point of curvature. Understanding the mechanisms of DW depinning in the inhomogeneous curved systems and evaluating the strength of DW pinning are helpful for the design of devices using DW motion, e.g. the race track memory [3].