Effect of charge modulation in (LaVO3)m(SrVO3)n superlattices on the insulator-metal transition

TL;DR

This study investigates how charge modulation in superlattices of LaVO3 and SrVO3 influences the insulator-metal transition, revealing that increasing periodicity induces metallic behavior, with a filling-controlled transition achieved by doping.

Contribution

It demonstrates how superlattice periodicity and doping control the insulator-metal transition in LaVO3/SrVO3 heterostructures, providing insights into charge carrier coherence and transition mechanisms.

Findings

Increasing superlattice period induces metallic behavior.

Charge carrier coherence length explains transition behavior.

Doping with SrVO3 layers enables filling-controlled insulator-metal transition.

Abstract

A series of epitaxial (LaVO3)6m(SrVO3)m superlattices having the same nominal composition as La6/7Sr1/7VO3, a Mott-Hubbard insulator, were grown with pulsed-laser deposition on [001]-oriented SrTiO3 substrates, and their superlattice period was varied. When m=1, the insulating resistivity of bulk-like La6/7Sr1/7VO3 is obtained; however, an increase in the periodicity (m>=2) results in metallic samples. Comparison of the superlattice periodicity with the coherence length of charge carriers in perovskite oxide heterostructures are used to understand these observations. A filling-controlled insulator-metal transition was induced by placing a single dopant layer of SrVO3 within LaVO3 layers of varying thickness.