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

TL;DR

This study uses DFT+DMFT to show that inserting SrVO$_3$ layers into LaVO$_3$ creates a stable, confined metallic layer that prevents a metal-insulator transition, with properties reestablishing within a few unit cells and weak strain effects.

Contribution

It demonstrates how interfacial doping in LaVO$_3$/SrVO$_3$ multilayers stabilizes metallicity and reveals the spatial extent of property reestablishment and strain effects using advanced theoretical methods.

Findings

A metallic layer is stabilized at the interface.

Bulk properties reemerge within 2-3 unit cells from the interface.

Strain modulation causes weak asymmetric charge reconstruction.

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.