Interfacial doping in LaVO$_3$/SrVO$_3$ multilayers from DFT+DMFT

Abstract

We investigate the effect of spatial doping of the Mott insulator LaVO$_3$ by inserting a few layers of the correlated metal SrVO$_3$ in multilayer geometries. Using density functional theory in combination with dynamical mean-field theory, we demonstrate that this leads to a geometrically confined and robust metallic layer that stabilizes the metallicity in SrVO$_3$ even in the ultrathin layer limit, suppressing a potential dimensionality-induced metal-insulator transition. For a thicker SrVO$_3$ layer, we find a continuous transition of both structural and electronic properties across the interface between the two materials, with bulk properties reestablished on a length scale of 2-3 unit cells away from the interface. We show that a strain modulation applied along the growth direction can lead to asymmetric charge reconstruction at chemically symmetric interfaces. However, we find that this effect is rather weak, implying that fractional occupancy, and thus metallicity, persists at the interfaces.