Ordering ferromagnetic In1−xMnxAs quantum dots

In this work, we present a method to order low temperature (LT) self-assembled ferromagnetic In1−xMnxAs quantum dots (QDs) grown by molecular beam epitaxy (MBE). The ordered In1−xMnxAs QDs were grown on top of a non-magnetic In0.4Ga0.6As/GaAs(100) QDs multi-layered structure. The modulation of the chemical potential, due to the stacking, provides a nucleation center for the LT In1−xMnxAs QDs. For particular conditions, such as surface morphology and growth conditions, the In1−xMnxAs QDs align along lines like chains. For comparison purposes, we also report the study of QDs grown on plain GaAs(100) substrates. Ferromagnetic behavior was observed for all structures at 2 K