Spin splitting in strained p-type quantum wells with and without an applied magnetic field

The spin splitting in the valence band in an InxGa1-xAs/InxGa1-xAsyP1-y quantum well is investigated theoretically using a 6×6 Luttinger Hamiltonian. We compare the Landau levels in a perpendicular magnetic field with the corresponding results for the subband dispersions. The influence of the inversion asymmetry of the zinc-blende lattice in combination with strain on the spin splitting is studied. The same influence from the asymmetry of the quantum well is investigated. It is shown that the asymmetry of the quantum well has a very small impact on the Landau level splitting in contrast to the subbands in the absence of a magnetic field. The asymmetry of the zinc-blende lattice contributes about 1 meV to the spin splitting under biaxial tension and leads to additional anticrossing behaviour of the Landau levels.