Abstract
By first-principles calculations we investigate the structural, electronic, and magnetic properties of the (LaMnO3)(2)/(SrTiO3)(2) superlattice. We find that a monoclinic C-2h symmetry is energetically favorable and that the spins order ferromagnetically. Under both compressive and tensile uniaxial strain the electronic structure of the superlattice shows a half-metallic character. In particular, a fully spin-polarized two-dimensional electron gas, which traces back to the Ti 3d(xy) orbitals, is achieved under compressive uniaxial strain.