Narrowband terahertz emission via selective spin-wave mode control in antiferromagnetic Er <i>x</i> Tm1− <i>x</i> FeO3

Y Yushuang Zhao (Terahertz Technology Innovation Research Institute, Terahertz Spectrum and Imaging Technology Cooperative Innovation Center, Shanghai Key Lab of Modern Optical System, University of Shanghai for Science and Technology 1 , Shanghai 200093,) X Xuewei Ju (Fujian Provincial Key Laboratory of Terahertz Functional Devices and Intelligent Sensing, School of Mechanical Engineering and Automation, Fuzhou University 2 , Fuzhou 350108,) J Jingxiu Liu (Materials Genome Institute, International Center for Quantum and Molecular Structures and Department of Physics, Shanghai University 3 , Shanghai 200444,) Z Zeru Liu (Materials Genome Institute, International Center for Quantum and Molecular Structures and Department of Physics, Shanghai University 3 , Shanghai 200444,) X Xiaoxuan Ma B Bo Lu X Xiangfeng Wang Z Zuanming Jin (Terahertz Technology Innovation Research Institute, Terahertz Spectrum and Imaging Technology Cooperative Innovation Center, Shanghai Key Lab of Modern Optical System) S Shixun Cao (Materials Genome Institute, International Center for Quantum and Molecular Structures and Department of Physics, Shanghai University 3 , Shanghai 200444,)

Abstract

Antiferromagnets, capable of hosting terahertz (THz)-frequency spin waves, are promising candidates for ultrafast, low-dissipation information processing. However, the systematic control of spin modes in antiferromagnetic orthoferrites remains relatively scarce. Here, we demonstrate the emission and detection of narrowband sub-THz radiation from quasi-ferromagnetic (q-FM) and quasi-antiferromagnetic (q-AFM) modes in ErxTm1−xFeO3 (x = 0, 0.5, and 1) single crystals. By varying the angle θ between the incident THz magnetic field (HTHz) and the c-axis, we can selectively excite either the q-AFM or q-FM mode and modulate their amplitude and relaxation dynamics. Furthermore, we show that the resonant THz frequencies in b-cut crystals are remarkably robust, exhibiting dependence on temperature and external magnetic fields (HDC). We calculated the magnetic anisotropy constants based on the temperature dependence of the spin waves. Finally, we generate narrowband THz emission via the inverse magneto-refraction effect by optically exciting q-AFM spin resonances.

Article Details

Volume / Issue Vol. 128, Issue 16
Published April 20, 2026
ISSN 0003-6951
Publisher American Institute of Physics

Journal Info

Applied Physics Letters

American Institute of Physics

ISSN: 0003-6951 Physical Sciences

Authors (9)

Y

Yushuang Zhao

Terahertz Technology Innovation Research Institute, Terahertz Spectrum and Imaging Technology Cooperative Innovation Center, Shanghai Key Lab of Modern Optical System, University of Shanghai for Science and Technology 1 , Shanghai 200093,

X

Xuewei Ju

Fujian Provincial Key Laboratory of Terahertz Functional Devices and Intelligent Sensing, School of Mechanical Engineering and Automation, Fuzhou University 2 , Fuzhou 350108,

J

Jingxiu Liu

Materials Genome Institute, International Center for Quantum and Molecular Structures and Department of Physics, Shanghai University 3 , Shanghai 200444,

Z

Zeru Liu

Materials Genome Institute, International Center for Quantum and Molecular Structures and Department of Physics, Shanghai University 3 , Shanghai 200444,

X

Xiaoxuan Ma

B

Bo Lu

X

Xiangfeng Wang

Z

Zuanming Jin

Terahertz Technology Innovation Research Institute, Terahertz Spectrum and Imaging Technology Cooperative Innovation Center, Shanghai Key Lab of Modern Optical System

S

Shixun Cao

Materials Genome Institute, International Center for Quantum and Molecular Structures and Department of Physics, Shanghai University 3 , Shanghai 200444,