Systematic motion of magnetic domain walls in notched nanowires under ultra-short current pulses

Abstract

The precise manipulation of transverse magnetic domain walls in finite/infinite nanowires with artificial defects under the influence of very short spin-polarized current pulses is investigated. We show that for a classical $3d$ ferromagnet material like Nickel, the exact positioning of the domain walls at room temperature is possible only for pulses with very short rise and fall time that move the domain wall reliably to nearest neighboring pinning position. The influence of the shape of the current pulse and of the transient effects on the phase diagram current-pulse length are discussed. We show that large transient effects appear even when $\alpha$=$\beta$, below a critical value, due to the domain wall distortion caused by the current pulse shape and the presence of the notches. The transient effects can oppose or amplify the spin-transfer torque (STT), depending on the ratio $\beta /\alpha$. This enlarges the physical comprehension of the DW motion under STT and opens the route to the DW displacement in both directions with unipolar currents.

References in corpus (5)

• Identification of the dominant precession damping mechanism in Fe, Co, and Ni by first-principles calculations
• Domain wall pinning and potential landscapes created by constrictions and protrusions in ferromagnetic nanowires
• Direct Observation of Massless Domain Wall Dynamics in Nanostripes with Perpendicular Magnetic Anisotropy
• Domain wall pinning and interaction in rough cylindrical nanowires
• 3D versus 2D domain wall interaction in ideal and rough nanowires