Artificially ordered Bi/Sb superlattice alloys: Fabrication and transport properties

We have fabricated Bi/Sb superlattice alloys that are artificially ordered on the atomic scale using molecular-beam epitaxy. We observe that by changing the superlattice period thickness, the electronic structure can be ``tuned'' from a semimetal, through zero gap, to a narrow-gap semiconductor. These unique properties, which are distinct from those in random alloys, are believed to be a consequence of ordered atomic configurations.