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Spectral and Angle-Resolved Magneto-Optical Characterization of Photonic Nanostructures
Published on: November 21, 2019
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Optical Magnetoelectric Resonance in a Polar Magnet (Fe,Zn)_{2}Mo_{3}O_{8} with Axion-Type Coupling
T Kurumaji1, Y Takahashi1,2,3, J Fujioka2
1RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan.
Physical Review Letters
|September 27, 2017
Summary
We observed terahertz light polarization rotation due to magnetoelectric (ME) spin excitations in multiferroics. This reveals novel optical functionality from diagonal ME coupling, offering insights into the dc linear ME effect.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Optics
Background:
- Multiferroic materials exhibit coupled magnetic and electric properties.
- Magnetoelectric (ME) effects are crucial for novel device applications.
- Spin excitations play a key role in multiferroic functionalities.
Purpose of the Study:
- To investigate the polarization rotation of terahertz light in multiferroics.
- To explore the relationship between terahertz light and magnetoelectric spin excitations.
- To understand the role of diagonal ME susceptibility in optical phenomena.
Main Methods:
- Resonant spectroscopy of terahertz light.
- Measurement of polarization rotation spectra.
- Analysis of thermal and magnetic-field evolution.
- Application of sum rules to spectral weight.
Main Results:
- Observed polarization rotation of terahertz light resonant with ME spin excitation in (Fe,Zn)2Mo3O8.
- Quantitatively reproduced polarization rotation spectra using frequency dispersion of diagonal ME susceptibility (axion term).
- Gained insight into the dc linear ME effect via sum rule on ME oscillator spectral weight.
Conclusions:
- Diagonal ME coupling in multiferroics enables novel optical functionalities.
- Spin excitations are a source of unique optical properties in multiferroics.
- The study provides a quantitative understanding of ME effects in the terahertz regime.
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