Spin-wave dynamics in perpendicularly magnetized antidot multilayers

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Perpendicular magnetic anisotropy (PMA) multilayers are crucial for spintronic devices.
• Nanoscale patterning, such as antidots, influences magnetic dynamics.
• Focused ion beam (FIB) milling can alter magnetic properties locally.

Purpose of the Study:

• To investigate the modulation of spin-wave (SW) dynamics by bias magnetic field orientation.
• To understand the role of nanoscale diamond-shaped antidots in controlling SW propagation.
• To explore the potential for next-generation nanoscale magnonic devices.

Main Methods:

• All-optical time-resolved magneto-optical Kerr effect (TR-MOKE) measurements.
• Micromagnetic modeling to interpret experimental observations.
• Fabrication of [Co/Pd] multilayers with nanoscale antidots using FIB.

Main Results:

• Efficient modulation of SW dynamics was achieved by varying magnetic field orientation.
• Lower frequency SW modes are linked to in-plane (IP) domain structures in shell regions around antidots.
• The IP magnetization direction in shell regions changes significantly with field orientation, affecting edge-localized SW modes.

Conclusions:

• The orientation-dependent coupling between edge-localized and bulk SWs in PMA systems offers novel physics.
• This work demonstrates prospects for developing energy-efficient, hybrid-system-based nanoscale magnonic devices.