Spin superlattice behavior in ZnSe/${\mathrm{Zn}}_{0.99}$${\mathrm{Fe}}_{0.01}$Se quantum wells

Spin superlattices with alternating nonmagnetic and magnetic layers, in which a tunable spin-dependent potential exists, have been fabricated. We show that the ZnSe/${\mathrm{Zn}}_{0.99}$${\mathrm{Fe}}_{0.01}$Se system, in which field-induced spin splittings in both valence and conduction bands can become much larger than the residual zero-field potentials, exhibits spin superlattice behavior. Low-temperature magnetoreflectance experiments have been used to investigate the nature of these structures, verifying through field-dependent spin splitting and transition strengths that they are in fact true spin superlattices.