Abstract-Terahertz Radiation from Magnetic Excitations in Diluted Magnetic Semiconductors

R. Rungsawang¹, F. Perez^2,*, D. Oustinov¹, J. Gómez^2,†, V. Kolkovsky³, G. Karczewski³, T. Wojtowicz³, J. Madéo¹,N. Jukam¹, S. Dhillon¹, and J. Tignon^1 
1Laboratoire Pierre Aigrain, Ecole Normale Supérieure, CNRS (UMR 8551), Université Pierre et Marie Curie, Université D. Diderot, 75231 Paris Cedex 05, France
²Institut des Nanosciences de Paris, CNRS (UMR7588), Université Paris VI, Paris 75005, France
³Institute of Physics, Polish Academy of Sciences, 02-668 Warsaw, Poland


http://prl.aps.org/abstract/PRL/v110/i17/e177203

We probed, in the time domain, the THz electromagnetic radiation originating from spins in CdMnTe diluted magnetic semiconductor 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-wave generation, spin precession, and of emission of THz radiation. Our results open new perspectives for improved control of the direct coupling between spin and an electromagnetic field, e.g., by using semiconductor technology to insert the THz sources in cavities or pillars.

© 2013 American Physical Society