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Spin-induced optical second harmonic generation in the centrosymmetric magnetic semiconductors EuTe and EuSe
B Kaminski1, M Lafrentz, R V Pisarev
1Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany.
Physical Review Letters
|October 2, 2009
Summary
Researchers discovered spin-induced optical second harmonic generation (SHG) in magnetic semiconductors EuTe and EuSe. This novel nonlinear optical effect arises from magnetic dipole contributions and magnetization, enabling SHG in centrosymmetric materials.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Nonlinear Optics
Background:
- Centrosymmetric magnetic semiconductors like EuTe and EuSe are typically not expected to exhibit second harmonic generation (SHG).
- Understanding nonlinear optical properties in magnetic materials is crucial for spintronics and optoelectronics.
Purpose of the Study:
- To investigate the origin of optical second harmonic generation (SHG) in centrosymmetric magnetic semiconductors EuTe and EuSe.
- To explore a novel type of nonlinear optical susceptibility linked to magnetic properties.
Main Methods:
- Optical spectroscopy was employed to study EuTe and EuSe.
- Measurements of magnetic field and temperature dependence were conducted to analyze the SHG signal.
Main Results:
- Spin-induced optical second harmonic generation (SHG) was observed in the band gap vicinity (2.1-2.4 eV) of EuTe and EuSe.
- The SHG signal was found to originate from the bulk of the materials.
- A novel nonlinear optical susceptibility, driven by magnetic dipole contributions and magnetization, was identified.
Conclusions:
- The study reveals a new mechanism for generating optical harmonics in centrosymmetric magnetic materials.
- This spin-induced susceptibility provides a pathway to utilize harmonics generation spectroscopy in a broader range of magnetic systems.
- The findings advance the understanding of light-matter interactions in magnetic semiconductors.
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