Tuning domain wall dynamics by shaping nanowires cross-sections

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanotechnology

Background:

• Domain wall (DW) dynamics in magnetic nanowires are fundamental for spintronic device applications.
• Understanding DW motion is crucial for controlling magnetic information at the nanoscale.

Purpose of the Study:

• To analyze the transverse domain wall motion in magnetic nanowires with polygonal cross-sections.
• To investigate the influence of cross-sectional geometry on DW dynamics and velocity.

Main Methods:

• Detailed analysis of transverse DW motion under applied magnetic fields.
• Utilized micromagnetic simulations to observe and quantify DW behavior.
• Developed an analytical model based on the general kinetic momentum theorem for explanation.

Main Results:

• Observed oscillatory DW motion above the Walker limit, dependent on the number of sides in the cross-section.
• DW velocity in triangular cross-section wires was an order of magnitude greater than in circular wires.
• Reduced cross-section area led to DW behavior comparable to cylindrical nanowires.

Conclusions:

• The geometry of the nanowire cross-section significantly impacts DW dynamics and velocity.
• Oscillatory DW behavior arises from energy changes due to DW shape deformations during rotation.
• The findings provide insights for designing advanced spintronic devices with enhanced performance.