Electronic Reconstruction in (LaVO3)(m)/SrVO3 (m=5, 6) Superlattices
Résumé
The (LaV3+O3)(m)/SrV4+O3 (m = 5, 6) superlattices are investigated by first principles calculations. While bulk LaVO3 is a C-type antiferromagnetic semiconductor and bulk SrVO3 is a paramagnetic metal, semiconducting A-type antiferromagnetic states for both superlattices are found due to epitaxial strain. At the interfaces, however, the V spins couple antiferromagnetically for m = 5 and ferromagnetically for m = 6 (m-dependence of the magnetization). Electronic reconstruction in form of charge ordering is predicted to occur with V3+ and V4+ states arranged in a checkerboard pattern on both sides of the SrO layer. As compared to bulk LaVO3, the presence of V4+ ions introduces in-gap states that strongly reduce the bandgap and influence the orbital occupation and ordering.