Electronic structure induced by lateral composition modulation in GaInAs alloys

It has been recently shown that growth of [001]-oriented short period $(AC)n/(BC)n$ vertical superlattices $(n∼1−2)$ spontaneously creates a lateral composition modulation in the substrate plane ([110] direction), where wire-like AC-rich and BC-rich domains alternate with a period of $∼100−200 Å.$ This creates a new type of lattice structure with orthogonal [001] and [110] strain fields and compositional waves. Using a three-dimensional plane-wave pseudopotential approach, we study here the electronic properties of this type of structure in a GaInAs alloy, predicting valence band splittings into distinctly polarized components, a $⩽100 meV$ band-gap reduction and strong, type I electron and hole confinement in the In-rich lateral channels.