Eur. Phys. J. B (2015) 88: 214
https://doi.org/10.1140/epjb/e2015-60421-x

Regular Article

Vortex-assisted domain wall depinning and propagation in notched nanowires

¹ Physics Department, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P.R. China
² HKUST Shenzhen Research Institute, Shenzhen 518057, P.R. China

^a e-mail: phxwan@ust.hk

Received: 29 December 2014
Received in final form: 27 May 2015
Published online: 2 September 2015

Abstract

Various notches are often introduced in spintronics to trap a domain wall (DW). Common wisdom would expect notches to strengthen DW pinning and to hinder DW motion. Interestingly, our simulations show that notches help electric current to depin a DW with the assistance of vortex generation. The DW displacement is insensitive to notch geometry and current density. This phenomenon is explained by the Thiele equation. Moreover, a current density below the intrinsic threshold value, which is the minimum current to sustain continuous DW motion in a uniform nanowire, can induce a continuous DW propagation along a wire with a series of notches.