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Spectral and Angle-Resolved Magneto-Optical Characterization of Photonic Nanostructures
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Nonlinear Photocurrent as a Probe of Magnetic Structures and Magnetoelectric Switching in Altermagnet
Huanhuan Yang1,2, Yee Sin Ang3, Sheng Meng1,2
1Songshan Lake Material Laboratory, Dongguan, Guangdong 523808, P.R. China.
The Journal of Physical Chemistry Letters
|December 26, 2025
Summary
Second-order photocurrents reliably detect magnetic structures and ferroelectric switching in altermagnets (AMs). This breakthrough enables optical readout of magnetoelectric states in these promising spintronic materials.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Spintronics
Background:
- Altermagnets (AMs) exhibit unique band splitting, offering potential for spintronics and nonlinear optoelectronics.
- Identifying AM magnetic configurations and magnetoelectric coupling is challenging.
Purpose of the Study:
- Establish second-order photocurrent as a sensitive probe for AM magnetic structures.
- Detect coupled magnetoelectric order and ferroelectric switching in AMs.
Main Methods:
- Relativistic magnetic point group analysis.
- Ab-initio calculations on MnSe.
- Second-order photocurrent measurements.
Main Results:
- Distinct photocurrent "fingerprints" identified for three MnSe magnetic configurations.
- Normal shift current direction depends on magnetic configuration (3.5-4.0 eV).
- Ferroelectric switching reverses photocurrent direction, enabling optical readout.
Conclusions:
- Second-order photocurrents are a reliable, symmetry-sensitive probe for AMs.
- Optical readout of magnetoelectric states in AMs is feasible.
- Enables advanced spintronic and optoelectronic applications.
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