Domain wall resistance in CoFeB-based heterostructures with interface Dzyaloshinskii-Moriya interaction

TL;DR

This study investigates how the domain wall resistance in CoFeB-based heterostructures is affected by interface Dzyaloshinskii-Moriya interaction and Ta layer thickness, revealing complexities in resistance measurement interpretations.

Contribution

It demonstrates the influence of interface Dzyaloshinskii-Moriya interaction on domain wall resistance and highlights challenges in distinguishing domain wall types via resistance measurements.

Findings

Domain wall resistance remains nearly constant with varying Ta thickness.

Additional magnetoresistance effects explain resistance in thick Ta films.

Discrepancies in thin Ta films suggest difficulty in identifying domain wall types from resistance.

Abstract

We have studied the domain wall resistance in W/Ta/CoFeB/MgO heterostructures. The Ta layer thickness is varied to control the type of domain walls via changes in the interfacial Dzyaloshinskii Moriya interaction. We find a nearly constant domain wall resistance against the Ta layer thickness. Adding contributions from the anisotropic magnetoresistance, spin Hall magnetoresistance and anomalous Hall effect describe well the domain wall resistance of the thick Ta layer films. However, a discrepancy remains for the thin Ta layer films wherein chiral N\'eel-like domain walls are found. These results show the difficulty of studying the domain wall type from resistance measurements.