Abstract-Terahertz radiation from magnetic excitations in diluted magnetic semiconductors

R. Rungsawang, F. Perez, D. Oustinov, J. Gómez, V. Kolkovsky, G. Karczewski, T. Wojtowicz, J. Madéo, N. Jukam, S. Dhillon, and J. Tignon
http://prl.aps.org/accepted/c1072Y88G3019b3ce3be8a80c1ecd8d7ec5bd5683
We probed in the time domain, the THz electromagnetic radiation originating from spins in CdMnTe diluted magnetic semiconductors quantum wells containing high mobility electron gas. Taking advantage of the efficient Raman generation process, the spin precession was induced by low power near-infrared pulses. We provide a full theoretical first-principles description of spin-waves generation, spin precession and of emission of the THz radiation. Our results open new perspectives for improved control of the direct coupling between spins and electromagnetic field, e.g. by using semiconductor technology to insert the THz sources in cavities or pillars.