Alexey Pavolotsky will hold his docent lecture entitled "Thin film fabrication for superconducting instrumentation as a multi-disciplinary subject".

Abstract

The characteristic feature of micro fabricating technology for the instrumentation made of superconducting circuits is its broad and multi-disciplinary nature: it starts from different aspects of micro fabricating technology and thin films and broadens towards material and surface science, and engineering.

An ultra-thin (about 3 atomic layer thick) tunnel barrier in Nb/Al-AlOx/Nb superconducting tunnel structure is in the heart of the superconducting circuits, both structurally and in terms of control over the electrical performance of the instruments made out of them. Understanding of the fine structure of the tunnel barrier is vital. However, there are virtually no standard analytical techniques, which suit this purpose. The unsatisfied demand for the appropriate analytical technique motivated studies of the tunnel barrier structure with yet uncommon spectroscopy of reflected electrons.

For years, since introduction of Nb/Al-AlOx/Nb tunnel junctions, variation of their properties under room temperature aging and annealing at elevated temperatures has been extensively discussed. However, no consistent explanation for the observed effects has been proposed. Diffusion and stress-related processes in the vicinity of the tunnel barrier seems bring homogeneous explanation to the observed aging and annealing effects.

In the lecture, I will discuss the abovementioned aspects of the field emphasizing upon their multi-disciplinary nature. Starting from these examples, I will develop towards the importance for the modern engineering education to be broad.