Magneto-Raman spectroscopy in the regime of the persistent spin helix

In this thesis, spin density excitations in 2-dimensional electron gases (2DEG) in gallium arsenide-based quantum well samples have been studied by utilizing resonant inelastic light scattering experiments (RILS). Due to an interplay of spin-orbit coupling effects, caused by the crystal symmetry and modulation doping, a highly symmetric, effective spin-orbit field is created in the 2DEG plane. Depending on the direction of their movement, the electron spins precess in a helix-like pattern, which is often referred to as the persistent spin helix (PSH). This unique symmetry leads to a theoretically infinite spin lifetime inside such structures, making them a potential platform for a new generation of spin transistors. In presence of the PSH regime, the huge spin splitting anisotropy at the Fermi energy is investigated in dependence of the in-plane crystal direction. Via external magnetic fields, a direct quantitative determination of important spin-orbit field parameters, including the intrinsic effective spin-orbit field strength and the effective electron |g| factor, is achieved. The interpretation of the obtained spectra from the RILS experiments is supported by a numerical line-shape analysis, which precisely confirms the determined sample parameters