Molecular dynamics study of the effect of substrate temperature on the barrier behavior in aluminum oxide Josephson junctions

Abstract

Although the quality and reliability of Josephson junctions have been improved considerably, the effect of preparation parameters on the structure and nanochemical properties of the barrier layer remains elusive. Here, we use molecular dynamics to study the relationship between the structure and morphology of tunnel barriers and the substrate temperature. We find that substrate temperature affects the atomic arrangement of the barrier, especially in the lower interface region. We also confirm the importance of the lower interface for studying the properties of Josephson junctions and the disordered properties of aluminum oxidation. This work will improve the Josephson junction physical vapor deposition process and lead to the development of a lower noise and more reliable quantum computer.