Resonance-Assisted Depinning of DMI-Stabilized Néel Domain Walls in Stepped Perpendicular Magnetic Nanowires Driven by Pulsed Currents.

Current-driven manipulation of magnetic domain walls (DWs) in perpendicularly magnetized nanowires is promising for spintronic memory and logic applications. In this work, micromagnetic simulations are used to investigate the depinning of DMI-stabilized Néel domain walls from a stepped pinning site under unipolar square-pulse current excitation. The effects of current density, pulse frequency, duty cycle, Dzyaloshinskii-Moriya interaction (DMI), and temperature are examined. The results show that pulse frequency and duty cycle strongly influence the oscillatory response of the pinned DW and can promote depinning through efficient coupling with localized DW dynamics. Increasing the current density enhances the oscillation amplitude and facilitates escape from the pinning region, while variations in DMI produce marked changes in pinning stability and magnetic configuration. Thermal fluctuations further modify the depinning behavior, particularly for stronger DMI, where the system evolves from stable pinning to thermally assisted escape and, at higher temperatures, to less stable magnetic states. Overall, the results show that pulse parameters, DMI strength, and temperature jointly control DW depinning and stability, providing further insight into the tuning of current-driven DW transport in geometrically confined spintronic structures.