Universal domain wall dynamics under electric field in Ta/CoFeB/MgO devices with perpendicular anisotropy

TL;DR

This paper demonstrates how electric fields can universally control domain wall velocities across different regimes in Ta/CoFeB/MgO devices, revealing a linear relationship and sign change in the Walker regime, advancing low-power magnetic device control.

Contribution

It introduces a universal model describing electric field effects on domain wall dynamics across multiple regimes, including the creep, flow, and Walker regimes.

Findings

Electric fields modulate domain wall velocities from creep to flow regimes.

A linear relationship between electric field and effective magnetic field is established.

Electric field effect changes sign in the Walker regime.

Abstract

Electric field effects in ferromagnetic/oxide dielectric structures provide a new route to control domain wall (DW) dynamics with low power dissipation. However, electric field effects on DW velocities have only been observed so far in the creep regime where DW velocities are low due to strong interactions with pinning sites. Here, we show gate voltage modulation of DW velocities ranging from the creep to the flow regime in Ta/Co40Fe40B20/MgO/TiO2 structures with perpendicular magnetic anisotropy. We demonstrate a universal description of the role of applied electric fields in the various pinning dependent regimes by taking into account an effective magnetic field being linear with the electric field. In addition, the electric field effect is found to change sign in the Walker regime. Our work opens new opportunities for the study and optimization of electric field effect at ferromagnetic metal/insulator interfaces.