# The effect of atomic structure on the electrical response of aluminium oxide tunnel junctions

## TL;DR

This study uses atomistic modeling and quantum transport simulations to explore how atomic structure variations in aluminium oxide tunnel junctions influence their electrical properties, aiding improved nanoelectronic device design.

## Contribution

It introduces detailed atomistic models and simulation methods to analyze the impact of atomic structure on electrical response in aluminium oxide tunnel junctions, advancing understanding of conduction mechanisms.

## Key findings

- Higher oxide density exponentially increases resistance.
- Oxygen deficiency creates metallic channels reducing resistance.
- Local potential variations lead to dominant conduction channels.

## Abstract

Many nanoelectronic devices rely on thin dielectric barriers through which electrons tunnel. For instance, aluminium oxide barriers are used as Josephson junctions in superconducting electronics. The reproducibility and drift of circuit parameters in these junctions are affected by the uniformity, morphology, and composition of the oxide barriers. To improve these circuits the effect of the atomic structure on the electrical response of aluminium oxide barriers must be understood. We create three-dimensional atomistic models of aluminium oxide tunnel junctions and simulate their electronic transport properties with the non-equilibrium Green's function formalism. Increasing the oxide density is found to produce an exponential increase in the junction resistance. In highly oxygen-deficient junctions we observe metallic channels which decrease the resistance significantly. Computing the charge and current density within the junction shows how variation in the local potential landscape can create channels which dominate conduction. An atomistic approach provides a better understanding of these transport processes and guides the design of junctions for nanoelectronics applications.