Emergence of quasi-two-dimensional electron gas at the interface of LaAlO3/Sr2AlNbO6(001) heterostructures

Quasi-two-dimensional electron gas (q-2DEG) at the interface of oxide heterostructures, as an alternative to semiconductor electronics, is limited by its low carrier mobility. This is largely due to the nature of Ti 3 d t 2 g conduction electrons of the SrTiO 3 substrate. Here, we explore the interface conductivity between LaAlO 3 / Sr 2 AlNbO 6 ( 001 ) using density functional theory based first principles calculations. These heterostructures show an insulator–metal transition with increasing overlayer thickness and the carriers being Nb 4 d x y in origin. The relatively higher dispersion of these carriers yields a higher carrier mobility and, hence, is significant to electronics applications based on q-2DEG.