Voltage-controlled domain wall traps in ferromagnetic nanowires

Area of Science:

• Spintronics
• Materials Science
• Nanotechnology

Background:

• Electrical control of magnetism is key for spintronic devices, often relying on magnetic domain wall manipulation.
• Previous methods using voltage-induced charge accumulation showed modest effects on domain wall motion in ferromagnetic nanowires.
• Existing techniques were limited to slow, thermally activated regimes, hindering practical applications.

Purpose of the Study:

• To explore voltage-induced interfacial chemistry modulation for nanoscale magnetic property switching.
• To develop strong, non-volatile voltage-controlled magnetic domain wall traps.
• To demonstrate a prototype non-volatile memory device utilizing this magneto-ionic effect.

Main Methods:

• Utilized a solid-state ionic conductor as a gate dielectric for voltage application.
• Investigated voltage-induced modulation of interfacial chemistry to influence magnetic properties.
• Characterized the strength and non-volatility of generated domain wall traps.

Main Results:

• Achieved unprecedentedly strong voltage-controlled domain wall traps with pinning strengths of at least 650 Oe.
• Demonstrated the ability to halt domain walls traveling at speeds up to ~20 m s⁻¹.
• Successfully implemented a prototype non-volatile memory device using these magneto-ionic traps for electrical bit selection.

Conclusions:

• Voltage-induced interfacial chemistry modulation offers a powerful route for nanoscale magnetic control.
• The magneto-ionic effect enables the creation of non-volatile, electrically programmable magnetic pinning sites.
• This breakthrough paves the way for next-generation spintronic devices and high-density non-volatile memory.