Proposal of a one-dimensional electron gas in the steps at the LaAlO$_3$-SrTiO$_3$ interface

TL;DR

This paper proposes that one-dimensional electron gases can be engineered at the step edges of LaAlO$_3$-SrTiO$_3$ interfaces, supported by first principles calculations and electrostatic modeling, offering a new way to enhance electronic interface functionalities.

Contribution

It introduces the concept of creating 1DEGs at interface step edges, expanding the potential for electronic device applications beyond 2DEGs.

Findings

1DEG can be formed at LAO/STO step edges due to electronic reconstruction.

First principles calculations support the stability of 1DEG at steps.

This approach offers a new route to increase functional density in oxide interfaces.

Abstract

The two-dimensional electron gas (2DEG) at the interface between LaAlO$_3$ (LAO) and SrTiO$_3$ (STO) has become one of the most fascinating and highly-debated oxide systems of recent times. Here we propose that a one-dimensional electron gas (1DEG) can be engineered at the step edges of the LAO/STO interface. These predictions are supported by first principles calculations and electrostatic modeling which elucidate the origin of the 1DEG as an electronic reconstruction to compensate a net surface charge in the step edge. The results suggest a novel route to increasing the functional density in these electronic interfaces.