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Magneto-Spectroscopy in Semiconductors

Tadashi Takamasu, Kanji Takehana, Yasutaka Imanaka
Nano Physics Group


Mission

Magneto-spectroscopy measurements are most useful methods to study energy states in solids. Spectroscopy in semiconductors under the magnetic field are quite important to find out new quantum phenomena, many body effects and also study band parameters. In NIMS, Photoluminescence, Faraday rotation, Cyclotron resonance and Electron spin resonance, various magneto-optical measurements have been performed for nano-structures of semiconductors and diluted magnetic semiconductors in the wide range of the photon energy at high steady magnetic fields up to 35T.

Recent results

Magneto-luminescence in Quantum Hall systems
Fig. 1 shows the magnetic field dependence of the photoluminescence in high quality CdTe/CdMgTe 2DEGs at high magnetic fields up to 35T. Oscillation in the luminescence intensity and its peak energy is clearly observed at integer filling factors.

Cyclotron resonance in ZnO 2D electron systems
Fig. 2 shows cyclotron resonance spectra in ZnMgO/ZnO 2DEGs with a sub-millimeter wave source. Cyclotron resonances are observed obviously. The polaron mass is obtained as m*=0.35m0 from the energy dependence of the resonant field.