Magnetic domain wall motion driven by an acoustic wave.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Acoustics and Magnetism

Background:

• Magnet-based information technologies promise low-loss data storage.
• Domain walls (DW) are crucial for manipulating magnetic information.
• Controlling DW motion with external stimuli is key for device applications.

Purpose of the Study:

• To investigate the control of domain wall motion using acoustic shear waves.
• To explore the influence of acoustic wave parameters on DW dynamics.
• To understand the nonlinear interactions between acoustic and magnetic systems.

Main Methods:

• Generation and propagation of acoustic shear waves.
• Observation and measurement of domain wall motion under acoustic excitation.
• Analysis of wave-vector, frequency, and amplitude dependencies.
• Characterization of nonlinear phenomena in the coupled system.

Main Results:

• Acoustic shear waves can effectively drive domain wall motion.
• DW velocities can reach a significant fraction of the speed of sound under specific resonance conditions.
• Resonance occurs due to wave reflection, dependent on frequency, angle, and amplitude.
• Strong nonlinearities observed, including negative slope in reflection peaks and s-shaped DW velocity dependence.

Conclusions:

• Acoustic shear waves offer a viable method for controlling domain wall dynamics.
• Resonance phenomena significantly enhance the efficiency of acoustic control.
• Nonlinear magnet-acoustic interactions are critical for understanding and exploiting these effects.