ESR studies of the Bychkov–Rashba field in modulation doped Si/SiGe quantum wells

We analyse the experimentally observed g-factor anisotropy and the ESR linewidth of 2D conduction electrons in Si/SiGe structures in terms of phenomenologically introduced parameters in the spin-dependent k·p Hamiltonian. A k-linear term, corresponding to the Bychkov–Rashba zero field spin splitting introduced originally for a k=0 conduction band, is found to be the dominant effect of the spin-orbit coupling.