Tailoring crosstalk between localized 1D spin-wave nanochannels using focused ion beams

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanotechnology

Background:

• 1D spin-wave conduits are key components for magnonics-based logic and computing.
• Controlling local magnetization dynamics in nanochannels is essential for efficient spin-wave steering in magnonic devices.

Purpose of the Study:

• Investigate localized dynamical modes in 1 µm-wide permalloy conduits.
• Explore methods for versatile control of spin-wave propagation in nanostructures.

Main Methods:

• Micro-resonator ferromagnetic resonance (FMR) technique to probe dynamical modes.
• Focused Ne+ ion irradiation and focused ion beam (FIB) milling to precisely modify conduit geometry.
• Spatially resolved Brillouin light scattering (BLS) microscopy for mode visualization.
• Micromagnetic simulations to confirm mode localization and frequency tuning.

Main Results:

• Observed lowest-energy edge mode in microstrips after trimming edges with ion irradiation.
• Identified additional resonances attributed to modes localized at inner edges after milling.
• BLS microscopy confirmed mode localization at outer/inner edges, agreeing with FMR data.
• Micromagnetic simulations showed modes localized within 15 nm of strip edges.

Conclusions:

• Focused ion beam milling allows precise control over spin-wave mode localization in permalloy conduits.
• Mode frequencies are tunable up to 5 GHz by adjusting magnetostatic coupling (spatial separation).
• Demonstrated a pathway for engineering spin-wave behavior in nanoconduits for advanced electronic applications.