SPIN SPLITTING IN A P-TYPE QUANTUM-WELL WITH BUILT-IN ELECTRIC FIELD AND MICROSCOPIC INVERSION ASYMMETRY

The strain dependence of the spin splitting of hole subbands in modula tion-doped asymmetric lattice-matched InxGa1-xAs/InxGa1-xAsyP1-y quant um wells on lattice-mismatched InxGa1-xAsyP1-y substrates is investiga ted theoretically using a 6 x 6 Luttinger-Kohn Hamiltonian. The influe nce of the built-in electric field, the microscopic inversion asymmetr y of the zinc-blende lattice, and the strain are taken into account an d analyzed for different widths of the quantum wells. The spin splitti ng is dominated by the effects of the electric field for compressive s train and small tensile strain. For large tensile strain the microscop ic inversion asymmetry is the most important origin of spin splitting. A local maximum of spin splitting is located at small tensile strain. For large compressive strain the spin splitting is strongly suppresse d whereas for large tensile strain the spin splitting increases with t he absolute value of strain. However, the spin splitting vanishes comp letely in some directions for tensile strain.