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Deterministic Magnetization Reversal in Synthetic Antiferromagnets using Natural Light
Yujing Du1, Yifan Zhao1, Lei Wang2
1Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, School of Electronic Science and Engineering, State Key Laboratory for Manufacturing Systems Engineering, The International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an, 710049, China.
Small (Weinheim an Der Bergstrasse, Germany)
|July 5, 2023
Summary
Visible light can now control magnetism in spintronic devices, enabling reversible switching between antiferromagnetic and ferromagnetic states. This innovation promises energy-efficient solar-driven memories with enhanced reliability and speed.
Area of Science:
- Spintronics
- Materials Science
- Photonics
Background:
- Traditional spintronics face limitations like heating and energy consumption.
- Existing voltage-driven methods suffer from interfacial corrosion.
- Novel methods for tuning ferromagnetism are needed for energy-saving and reliable spintronics.
Purpose of the Study:
- To demonstrate visible light control of interfacial exchange interaction.
- To achieve reversible switching between antiferromagnetic (AFM) and ferromagnetic (FM) states using light.
- To develop energy-efficient and reliable spintronic devices.
Main Methods:
- Photoelectron doping into CoFeB/Cu/CoFeB/PN Si heterostructures using visible light.
- Magnetic optical Kerr effect measurements to analyze domain switching.
- First-principle calculations to understand the underlying mechanism.
- Fabrication of a prototype device for visible light control.
Main Results:
- Complete and reversible switching between AFM and FM states with visible light.
- Deterministic 180° magnetization switching controlled by visible light and a small magnetic bias field.
- Demonstrated photoelectron doping increases exchange interaction by raising Fermi energy.
- A prototype device showed a 0.35% giant magnetoresistance ratio change for two-state switching.
Conclusions:
- Visible light can effectively tune interfacial exchange interactions in synthetic antiferromagnetic heterostructures.
- This light-driven approach offers a pathway for fast, compact, and energy-efficient solar-driven memory devices.
- The findings overcome limitations of current-driven and voltage-driven spintronics.
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