Large band offset as driving force of two-dimensional electron confinement: The case of SrTiO3/SrZrO3 interface

Using advanced first-principles calculations we predict that the nonpolar SrTiO3/SrZrO3 (001) interface, designed as either thin SrZrO3 film deposited on SrTiO3 or short-period (SrTiO3)m/(SrZrO3)n superlattice, hosts a two-dimensionally confined electron gas. Mobile electron charge due to native impurities, field effect, or modulation doping remains tightly trapped at the interface. Key ingredients for this occurrence are (a) the peculiar chemistry of 3d orbitals and (b) the large band offset at the titanate-zirconate interface.