Terahertz emission from magnetoplasma oscillations in semiconductors
| Autor: | Karl Unterrainer, H. Wrage, Pelagia Neocleous, Paul A. Crowell, C. Lind, James Heyman, D. Hebert, Thomas Mueller |
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| Rok vydání: | 2002 |
| Předmět: |
Physics
Condensed Matter::Other business.industry Terahertz radiation Astrophysics::High Energy Astrophysical Phenomena Physics::Optics Condensed Matter::Mesoscopic Systems and Quantum Hall Effect Laser Plasma oscillation law.invention Terahertz spectroscopy and technology Photoexcitation Condensed Matter::Materials Science law Optoelectronics Emission spectrum business Plasmon Quantum well |
| Zdroj: | SPIE Proceedings. |
| ISSN: | 0277-786X |
| Popis: | Ultrafast terahertz spectroscopy can be used to probe charge and spin dynamics in semiconductors. We have studied THz emission from bulk InAs and GaAs and from GaAs/AlGaAs quantum wells as a function of magnetic field. Ultrashort pulses of THz radiation were produced at semiconductor surfaces by photoexcitation with a femtosecond Ti-Sapphire laser, and we recorded the THz emission spectrum and the integrated THz power as a function of magnetic field and temperature. In bulk samples the emitted radiation is produced by coupled cyclotron-plasma oscillations: we model THz emission from n-GaAs as magneto-plasma oscillations in a 3-D electron gas. THz emission from a modulation-doped parabolic quantum well is described in terms of coupled intersubband-cyclotron motion. A model including both 3-D plasma oscillations and a 2-D electron gas in a surface accumulation layer is required to describe THz emission from InAs in a magnetic field. |
| Databáze: | OpenAIRE |
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