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Electric-field-assisted switching in magnetic tunnel junctions
Wei-Gang Wang1, Mingen Li, Stephen Hageman
1Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218, USA. wgwang@pha.jhu.edu
Nature Materials
|November 15, 2011
Summary
Researchers demonstrate electric-field-assisted switching in magnetic tunnel junctions. This voltage-controlled method offers a path to ultralow energy consumption for spintronic devices.
Area of Science:
- Spintronics
- Condensed Matter Physics
- Materials Science
Background:
- Spin transfer torque (STT) enables current-driven magnetic switching in nanostructures.
- High critical current densities (10^6–10^7 A cm⁻²) limit STT's energy efficiency.
- Voltage-controlled magnetic switching is highly desirable for reduced power consumption.
Purpose of the Study:
- To investigate electric-field-assisted switching in magnetic tunnel junctions (MTJs).
- To explore voltage control over magnetic properties and tunneling magnetoresistance.
- To reduce the energy required for magnetic switching in spintronic devices.
Main Methods:
- Fabrication of CoFeB/MgO/CoFeB magnetic tunnel junctions with perpendicular magnetic anisotropy.
- Application of voltage pulses to induce electric-field-assisted switching.
- Measurement of coercivity, magnetic configuration, and tunneling magnetoresistance (TMR).
Main Results:
- Demonstrated reversible electric-field-assisted switching in CoFeB/MgO/CoFeB MTJs.
- Voltage pulses successfully manipulated coercivity, magnetic configuration, and TMR.
- Achieved switching with significantly lower current densities compared to conventional STT.
Conclusions:
- Electric-field-assisted switching is a viable pathway for ultralow energy magnetic switching in MTJs.
- This work opens new possibilities for voltage-controlled spintronic devices.
- Highlights the potential of electric fields to control magnetic properties at interfaces.
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