Atomic-scale Ti3SiC2 bilayers embedded in SiC: Formation of point Fermi surface

Semiconductor heterostructures provide a fertile ground for fascinating physical behaviors that are not present in their respective bulk constituents. Here we demonstrate, by combining advanced transmission electron microscopy with atomistic first-principles calculations, that an atomic-scale Ti3SiC2-like bilayer can be embedded in SiC interior, forming an atomically ordered multilayer that exhibits an unexpected electronic state with point Fermi surface. The valence charge is confined largely to within the bilayer in a spatially connected manner, serving possibly as a conducting channel to enhance the current flow over the semiconductor. Such a heterostructure with unusual properties is mechanically robust, rendering its patterning for technological applications likely. (C) 2011 American Institute of Physics. [doi:10.1063/1.3560505]