Elevation of Domain Wall Velocity Driven by Current Pulses in 2D Ferromagnetic Material Fe_3GeTe_2

摘要

Controlling the domain wall motion in the 2D ferromagnetic materials issignificantly critical to the topological spin electronics, non-volatile magneticmemories, and logic devices. The elevation of the domain wall velocityhas become an urgent challenge. Herein, a current-pulse-driving strategyis unprecedentedly established to boost the domain wall velocity with anout-of-plane magnetic field and a rising temperature in the Fe_3GeTe_2 by usingthe in situ Lorentz Transmission Electron Microscopy. Elevation of domainwall velocity depends on the demagnetization energy increase and Zeemanenergy reduction, which originates from the magnetic moments tilting by anon-parallel to the magnetic field. By injecting ≈2000 times of alternative currentpulses, a uniform instead of an unsynchronized domain wall velocity isachieved. The key mechanism lies in the decrease of the domain wall number,leading to a reduction in the expansion and compression of the domainareas. Optimized pulse parameters are applied with a critical duration of60 ns and the density of ≈2 × 10~(10) A m~(?2), leading to an elevation of velocityfrom 0.0308 to 0.39 m s?1. The elevation in magnetic domain wall velocity canbe useful for the application of 2D van der Waals ferromagnetic materials infuture spintronic devices.