Nonlinear Hall effect and multichannel conduction in LaTiO3/SrTiO3 superlattices

TL;DR

This study investigates the nonlinear Hall effect and multichannel conduction at LaTiO3/SrTiO3 heterointerfaces, revealing temperature and electric field control of interfacial charge transport due to electronic reconstruction.

Contribution

It demonstrates the presence of multichannel conduction and nonlinear Hall effects in LaTiO3/SrTiO3 superlattices, highlighting the role of dielectric properties and electronic reconstruction.

Findings

Nonlinear Hall resistivity at low temperatures

Electric field influences conduction channel distribution

Highly mobile conduction channel identified

Abstract

We report magneto-transport properties of heterointerfaces between the Mott insulator LaTiO3 and the band insulator SrTiO3 in a delta-doping geometry. At low temperatures, we have found a strong nonlinearity in the magnetic field dependence of the Hall resistivity, which can be effectively controlled by varying the temperature and the electric field. We attribute this effect to multichannel conduction of interfacial charges generated by an electronic reconstruction. In particular, the formation of a highly mobile conduction channel revealed by our data is explained by the greatly increased dielectric permeability of SrTiO3 at low temperatures, and its electric-field dependence reflects the spatial distribution of the quasi-two-dimensional electron gas.