Probing the metal-insulator transition of NdNiO3 by electrostatic doping

TL;DR

This study demonstrates that electrostatic doping via remote charge transfer can modulate the metal-insulator transition in NdNiO3 films, providing a new way to control electronic phases without lattice distortions.

Contribution

It introduces and experimentally validates a method of electrostatic doping through remote charge transfer to control the metal-insulator transition in NdNiO3.

Findings

Remote doping changes charge carrier density in NdNiO3.

The metal-insulator transition temperature shifts moderately with doping.

The results support theoretical models of band filling control in Mott transitions.

Abstract

Modulation of the charge carrier density in a Mott material by remote doping from a highly doped conventional band insulator is proposed to test theoretical predictions of band filling control of the Mott metal-insulator transition without introducing lattice distortions or disorder, as is the case for chemical doping. The approach is experimentally tested using ultrathin (2.5 nm) NdNiO3 films that are epitaxially grown on La-doped SrTiO3 films. We show that remote doping systematically changes the charge carrier density in the NdNiO3 film and causes a moderate shift in the metal-insulator transition temperature. These results are discussed in the context of theoretical models of this class of materials exhibiting a metal-insulator transition.