Broadband magneto-optical absorption by a Rashba spintronic system

We examine the selection rules for electron-photon interaction in a two-dimensional electron gas (2DEG) in the presence of the Rashba spin-orbit interaction and quantizing magnetic fields. In such a case, new channels open up for electronic transition accompanied by the absorption of photons. As a result, two absorption peaks and a broadband absorption spectrum can be observed for high-mobility samples at relatively high magnetic fields. We find that electronic transitions between the neighboring Landau levels within the same spin orientation are the main channels for magneto-optical absorption in a spin-split 2DEG.