Composition-driven Mott transition within SrTi$_{\rm 1-x}$V$_{\rm x}$O$_3$

TL;DR

This study investigates the metal-insulator transition in SrTi$_{1-x}$V$_x$O$_3$ driven by doping, revealing the role of electron correlations and site disorder through advanced theoretical modeling, and demonstrating potential for electronic device applications.

Contribution

The paper combines DFT+DMFT calculations to elucidate the doping-induced Mott transition in SrTi$_{1-x}$V$_x$O$_3$, highlighting the interplay of electron correlations and site disorder.

Findings

Doping induces a metal-insulator transition in SrTi$_{1-x}$V$_x$O$_3$.

Electron correlations within t$_{2g}$ orbitals drive the Mott physics.

External perturbations can switch the system between insulating and metallic phases.

Abstract

The last few decades has seen the rapid growth of interest in the bulk perovskite-type transition metal oxides SrVO$_3$ and SrTiO$_3$. The electronic configuration of these perovskites differs by one electron associated to the transition metal species which gives rise to the drastically different electronic properties. Therefore, it is natural to look into how the electronic structure transitions between these bulk structures by using doping. Measurements of the substitutional doped SrTi$_{\rm 1-x}$V$_{\rm x}$O$_3$ shows an metal-insulator transition (MIT) as a function of doping. By using supercell density functional theory with dynamical mean field theory (DFT+DMFT), we show that the MIT is indeed the result of the combination of local electron correlation effects (Mott physics) within the t$_{\rm 2g}$ orbitals and the atomic site configuration of the transition metals which may indicate dependence on site disorder. SrTi$_{\rm 1-x}$V$_{\rm x}$O$_3$ may be an ideal candidate for benchmarking cutting-edge Mott-Anderson models of real systems. We show that applying an effective external perturbation on SrTi$_{\rm 1-x}$V$_{\rm x}$O$_3$ can switch the system between the insulating and metallic phase, meaning this is a bulk system with the potential use in Mott electronic devices.