Spin-moment formation and reduced orbital polarization in LaNiO3/LaAlO3 superlattice: LDA plus U study

Density functional band calculations have been performed to study LaNiO3/LaAlO3 superlattices. Motivated by recent experiments reporting the magnetic and metal-insulator phase transition as a function of LaNiO3 layer thickness, we examined the electronic structure, magnetic properties, and orbital occupation depending on the number of LaNiO3 layers. Calculations show that the magnetic phase is stabler than the nonmagnetic for finite and positive U values. The orbital polarization is significantly reduced by U even in the magnetic regions. The implications of the results are discussed in comparison to recent experimental and theoretical studies within the limitations of the LDA + U method.