Spin-superlattice formation in a type-II ZnSe/Zn0.96Fe0.04Se multiple-quantum-well structure

We have investigated the carrier spin segregation process in a ZnSe/${\mathrm{Zn}}_{0.96}$ ${\mathrm{Fe}}_{0.04}$Se quantum-well structure by studying the energy and relative intensity of the ground-state exciton components as a function of applied magnetic field. The ${\mathit{e}}_1$ ${\mathit{h}}_1$ heavy-hole exciton initially tends towards type-II behavior as the field is applied but the trend reverses itself at higher fields as the conduction-band splitting of the magnetic barriers becomes significant. The interplay between the electron-hole Coulomb attraction and the tunable type-II confining potentials is described in the context of a variational model.