Two-dimensional superconductivity induced by high-mobility carrier doping in LaTiO3/SrTiO3 hetero-structures

TL;DR

This study demonstrates that high-mobility carrier doping at LaTiO3/SrTiO3 interfaces induces a tunable two-dimensional superconducting electron gas, with properties modifiable via electrostatic gating.

Contribution

It reveals the formation of a 2D superconducting electron gas at the interface, controllable by back-gate voltage and carrier doping, highlighting the role of high-mobility electrons.

Findings

Superconductivity occurs at the LaTiO3/SrTiO3 interface.

High-mobility electrons are responsible for superconductivity.

The electron distribution can be modulated by electrostatic gating.

Abstract

In this letter, we show that a superconducting two-dimensional electron gas is formed at the LaTiO3/SrTiO3 interface whose transition temperature can be modulated by a back-gate voltage. The gas consists of two types of carriers : a majority of low-mobility carriers always present, and a few high-mobility ones that can be injected by electrostatic doping. The calculation of the electrons spatial distribution in the confinement potential shows that the high-mobility electrons responsible for superconductivity set at the edge of the gas whose extension can be tuned by field effect.