CYCLOTRON AND ELECTRIC-DIPOLE SPIN RESONANCES IN A 2-DIMENSIONAL ELECTRON-GAS IN THE VICINITY OF THE CROSSING OF SPIN-SPLIT LANDAU-LEVELS

The fine structure of cyclotron (CR) and electric-dipole spin (EDSR) resonances in a heterostructure has been studied near the spin-split Landau-level crossing in a tilted magnetic field. Spin-orbit coupling splits the lines of the mixed CR-EDSR spectrum, the gaps being linear in the spin-orbit interaction. This effect is shown to be pronounced at the lowest Landau levels and sensitive to the magnetic-field orientation in the plane in the case of wide quantum wells. The polarization dependence of the EDSR efficiency far from the crossing region can help in distinguishing different spin-orbital terms in the effective two-dimensional Hamiltonian.