Tunable 2-dimensional/3-dimensional electron gases by submonolayer La doping of SrTiO_{3}

TL;DR

This study uses first-principles calculations to explore how submonolayer La doping in SrTiO₃ creates tunable 2D and 3D electron gases, revealing a dimensionality crossover with potential for studying various electronic properties.

Contribution

It demonstrates a method to induce and control a dimensionality crossover in oxide superlattices through low-level La doping, providing new insights into electronic behavior in these materials.

Findings

Identification of a 3D to 2D electronic crossover.

Presence of two distinct carrier types with tunable transport.

Potential to study phenomena like superconductivity through dimensional control.

Abstract

First-principles calculation was used to study the structural and electronic features of the low dimensional oxide structure, SrTiO_{3}/Sr_{1-x}La_{x}TiO_{3} (x=0.25) superlattices, constructed by submonolayer low dimensional La doping into SrTiO_{3}. We demonstrate a dimensionality crossover from three-dimensional to two-dimensional (3D \to 2D) electronic behavior in the system. Two types of carriers, one confined to 2D and the other extended, exhibit distinct tunable (3D \to 2D) transport characteristics that will enable the study of many properties (e.g., superconductivity) through this change in dimensionality.