Valence-band states in diluted magnetic semiconductor quantum wires

Abstract

We present a theoretical study of the valence-band states in diluted magnetic semiconductor quantum wire structures. As a consequence of confinement in two directions, the hole states in a quantum wire are known to be mixtures of heavy- and light-hole components. Due to a strong p-d exchange interaction in diluted magnetic semiconductors, the relative contribution of these components is strongly affected by an external magnetic field B, a feature that is absent in nonmagnetic quantum wires. This leads, in turn, to a strong magnetic-field dependence of the probabilities of various optical dipole transitions in diluted magnetic semiconductor quantum wires. Numerical calculations performed for the case of ${\mathrm{Cd}}_{1\ensuremath{-}x}{\mathrm{Mn}}_{x}{\mathrm{T}\mathrm{e}/\mathrm{C}\mathrm{d}}_{1\ensuremath{-}x\ensuremath{-}y}{\mathrm{Mn}}_{x}{\mathrm{Mg}}_{y}\mathrm{Te}$ T-shaped quantum wires demonstrate the possibility to efficiently control the polarization characteristics of light emitted from such structrures by means of an external magnetic field B.