Current-induced skyrmion generation and dynamics in symmetric bilayers

Area of Science:

• Condensed Matter Physics
• Materials Science

Background:

• Magnetic skyrmions are topologically protected quasiparticles with potential for nanoscale magnetization control.
• Their stabilization typically requires broken inversion symmetry and significant Dzyaloshinskii-Moriya interaction (DMI).

Purpose of the Study:

• To demonstrate skyrmion stabilization in a symmetric magnetic system.
• To explore methods for stabilizing skyrmions with reduced DMI.
• To investigate electric current-driven manipulation of skyrmions.

Main Methods:

• Utilized a symmetric magnetic bilayer system.
• Combined Dzyaloshinskii-Moriya interaction (DMI) and dipolar coupling effects for stabilization.
• Fabricated a device with asymmetric electrodes for current-driven control.
• Confirmed skyrmionic nature using gyrotropic force analysis.

Main Results:

• Successfully stabilized a pair of coupled skyrmions with opposite chiralities in a symmetric bilayer.
• Achieved skyrmion stabilization with lower DMI than previously required.
• Demonstrated independent writing and shifting of skyrmions using electric current at high velocities.
• Confirmed the quasiparticles' skyrmionic nature via gyrotropic force.

Conclusions:

• This work presents a novel approach for stabilizing magnetic skyrmions in symmetric systems, reducing reliance on high DMI.
• The demonstrated electric current control of skyrmions at high velocities is crucial for spintronic applications.
• These findings provide a foundation for developing robust skyrmion-based spintronic technologies.