Electric Field Tuned Dimensional Crossover in Ar-Irradiated SrTiO3

TL;DR

This study investigates how an electric field influences the dimensionality of electron transport in Ar-irradiated SrTiO3, revealing a tunable crossover between 3D and 2D behaviors driven by carrier confinement modulation.

Contribution

It demonstrates electric field control over the dimensional crossover in SrTiO3, linking dielectric properties to transport dimensionality, which is novel for oxide electronic device applications.

Findings

High mobility shows 3D orbital magnetoresistance.

Low mobility exhibits negative magnetoresistance due to weak localization.

Electric field modulates carrier confinement and dielectric constant.

Abstract

We present low temperature magnetoresistance measurements of Ar-irradiated SrTiO3 under an applied electrostatic field. The electric field, applied through a back gate bias, modulates both the mobility and sheet density, with a greater effect on the former. For high mobilities, 3-dimensional orbital magnetoresistance is observed. For low mobilities, negative magnetoresistance that is consistent with the suppression of 2-dimensional weak-localization is observed. The crossover from 3 to 2-dimensional transport arises from a modulation in the carrier confinement, which is enhanced by the electric field dependent dielectric constant of SrTiO3. The implications of our results on the development of oxide electronic devices will be discussed.