Band structure engineering of LaMnO3:SrTiO3 superlattices at the molecular level*

We have made single crystal short period superlattices consisting of alternating slabs of LaMnO3 and SrTiO3, using atomic layer by layer molecular beam epitaxy. The supercells consist of N-layers of each component, with N=1, 2, 3, 4. Ellipsometric measurements of the new materials show that optical absorption in the visible light range is significantly different from bulk LaMnO3 or SrTiO3, and depends on N. The new band structure is dependent on the superlattice design. This is an example of engineered coherent ``meta-materials'', and this fabrication technique can be extended to other lattice matched transition metal oxides with a wide range of conducting and magnetic properties.