Fast-electron magneto-optical spectrum of a two-dimensional electron gas in the presence of spin-orbit interaction and quantizing magnetic fields

In this paper, we present a theoretical study of the optical spectrum induced by electron-electron interaction in a spin-split two-dimensional electron gas (2DEG) in the presence of high magnetic fields. The presence of the Zeeman splitting and the Rashba spin-orbit interaction (RSOI) is considered so that the profile of the magneto-optical conductivity depends strongly on spintronic coefficients. We find that in sharp contrast to the case of a spin-degenerate 2DEG, the presence of the RSOI in a 2DEG can open up new channels for magneto-optical transition via absorption scattering. The unique features of the selection rules for optical transition in a spin-split 2DEG are examined and the dependence of the magneto-optical spectrum on radiation frequency, magnetic field, and sample parameters is discussed. This study is relevant to the characterization of the Rashba spintronic systems using magneto-optical experiments and to the application of systems such as terahertz magneto-optical devices.