Modulation doping in LaNiO$_3$/SrIrO$_3$ superlattices from first principles

Doping is commonly used to tune and optimize material properties such as conductivity and optical properties. Doping at extremely high concentrations, at the level of an electron per formula unit, can stabilize novel phases. Here we study lanthanum nickelate (LaNiO$_3$)/strontium iridate (SrIrO$_3$) superlattices using the first-principles density functional theory (DFT) +U method, focusing on the 1/1 superlattice. For this superlattice we find that there is a complete modulation doping in which one electron per formula unit is transferred from the SrIrO$_3$ layers to the LaNiO$_3$ layers, converting all nickels from Ni$^{3+}$ to Ni$^{2+}$ in the electron-doped LaNiO$_3$ layers and and all iridiums from Ir$^{4+}$ to Ir$^{5+}$ in the hole-doped SrIrO$_3$ layers. We will present results on the low energy structures and orbital occupations as well as the electronic and magnetic structures.