Uniaxial strain-modulated conductivity in manganite superlattice (LaMnO3/SrMnO3)

We have investigated the magnetic ordering and electrical conductivity transitions of (LaMnO3)2/(SrMnO3)2 superlattices grown on SrTiO3 substrate based on density-functional theory. It is found that the uniaxial tensile strain along the z axis of about 1.4% induced a magnetic transition from antiferromagnetic to ferromagnetic ordering. At the interface the orbital order changes from a combination of x2−y2 and 3z2−r2 to x2−y2 as strain becomes more compressive; as a result the electrical transport is transformed from three-dimensions to two-dimensions at the high uniaxial compressive strain. Our results suggest that the out-of-plane electrical conductivity can be modulated and controlled by uniaxial strain.