Interface-driven chiral magnetism and current-driven domain walls in insulating magnetic garnets

Area of Science:

• Condensed Matter Physics
• Materials Science
• Spintronics

Background:

• Magnetic oxides are crucial for spintronic applications like memory and logic.
• Chiral magnetism and efficient domain wall motion are key for advanced spintronic devices.
• Previous research focused on heavy metal layers for spin-orbit effects, but chiral magnetism in oxides remained elusive.

Purpose of the Study:

• To discover chiral magnetism in magnetic oxides.
• To investigate pure spin-current-driven domain wall motion in ferrimagnetic iron garnets.
• To explore the potential for high-velocity domain wall dynamics in these materials.

Main Methods:

• Epitaxial growth of rare-earth iron garnet films with perpendicular magnetic anisotropy.
• Utilizing adjacent platinum layers to generate spin currents.
• Characterizing homochiral Néel domain walls and measuring their velocity.

Main Results:

• Discovery of chiral magnetism in ferrimagnetic iron garnets.
• Observation of homochiral Néel domain walls.
• Achieved domain wall velocities exceeding 800 m/s driven by spin current from platinum.
• Demonstrated high velocities despite a small interfacial Dzyaloshinskii-Moriya interaction, attributed to antiferromagnetic spin dynamics.

Conclusions:

• Ferrimagnetic iron garnets exhibit chiral magnetism, enabling efficient spin-current-driven domain wall motion.
• The observed high domain wall velocities open new avenues for spintronic device applications.
• This finding expands the possibilities for utilizing magnetic oxides in next-generation electronic technologies.