Related Experiment Video
Updated: Sep 1, 2025
10:54
Design, Fabrication, and Experimental Characterization of Plasmonic Photoconductive Terahertz Emitters
Published on: July 8, 2013
15.0K
Antiferromagnetic-Ferromagnetic Heterostructure-Based Field-Free Terahertz Emitters
Xiaojun Wu1,2, Hanchen Wang3,4, Haijiang Liu5
1School of Electronic and Information Engineering, Beihang University, Beijing, 100191, P. R. China.
Advanced Materials (Deerfield Beach, Fla.)
|August 11, 2022
Summary
Researchers developed a novel antiferromagnetic-ferromagnetic heterostructure for efficient terahertz (THz) emission without external magnetic fields. This breakthrough advances spintronic THz optoelectronic devices by enabling field-free operation.
Area of Science:
- Spintronics
- Terahertz (THz) Photonics
- Materials Science
Background:
- Ferromagnetic-heterostructure spintronic terahertz (THz) emitters offer high efficiency, stability, and scalability for next-generation THz sources.
- Current THz emitters necessitate external magnetic fields for spin-to-charge conversion, hindering practical device applications.
- The development of magnetic-field-free THz emission is crucial for advancing spintronic THz optoelectronics.
Purpose of the Study:
- To innovate an antiferromagnetic-ferromagnetic heterostructure capable of efficient THz radiation generation without external magnetic fields.
- To investigate the underlying physical mechanisms, including exchange bias and enhanced anisotropy, responsible for field-free THz emission.
- To optimize heterostructure design for enhanced THz emission intensity and explore THz polarization control.
Main Methods:
- Fabrication of an antiferromagnetic-ferromagnetic heterostructure using IrMn3 and Co20Fe60B20 layers.
- Optimization of a trilayer heterostructure (IrMn3|Co20Fe60B20|W) by precisely balancing exchange bias and THz radiation efficiency.
- Characterization of THz emission intensity and polarization control through sample azimuthal angle rotation.
Main Results:
- Demonstration of efficient THz radiation generation from the IrMn3|Co20Fe60B20 heterostructure without any external magnetic field.
- An optimized 5.6 nm-thick IrMn3|Co20Fe60B20|W trilayer exhibited superior THz emission intensity compared to Pt|Co20Fe60B20|W.
- THz emission intensity was further enhanced by combining trilayer and bilayer samples, and polarization was flexibly controlled.
Conclusions:
- The developed antiferromagnetic-ferromagnetic heterostructure enables efficient, field-free coherent THz emission, overcoming a key limitation of current spintronic THz sources.
- The findings highlight the potential of exchange bias and enhanced anisotropy in driving efficient THz generation without external magnetic fields.
- This work paves the way for the development of practical, compact, and actively controllable spintronic THz optoelectronic devices.
