Aluminium-oxide wires for superconducting high kinetic inductance circuits

Rotzinger, H., Skacel, S.T., Pfirrmann, M., Voss, J.N., Münzberg, J., Probst, S., Bushev, P., Weides, M.P. , Ustinov, A.V. and Mooij, J.E. (2016) Aluminium-oxide wires for superconducting high kinetic inductance circuits. Superconductor Science and Technology, 30(2), 025002. (doi:10.1088/0953-2048/30/2/025002)

[img]
Preview
Text
155819.pdf - Accepted Version

1MB

Abstract

We investigate thin films of conducting aluminium-oxide, also known as granular aluminium, as a material for superconducting high quality, high kinetic inductance circuits. The films are deposited by an optimised reactive DC magnetron sputter process and characterised using microwave measurement techniques at milli-Kelvin temperatures. We show that, by precise control of the reactive sputter conditions, a high room temperature sheet resistance and therefore high kinetic inductance at low temperatures can be obtained. For a coplanar waveguide resonator with 1.5 kΩ sheet resistance and a kinetic inductance fraction close to unity, we measure a quality factor in the order of 700 000 at 20 mK. Furthermore, we observe a sheet resistance reduction by gentle heat treatment in air. This behaviour is exploited to study the kinetic inductance change using the microwave response of a coplanar wave guide resonator. We find the correlation between the kinetic inductance and the sheet resistance to be in good agreement with theoretical expectations.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Weides, Professor Martin
Authors: Rotzinger, H., Skacel, S.T., Pfirrmann, M., Voss, J.N., Münzberg, J., Probst, S., Bushev, P., Weides, M.P., Ustinov, A.V., and Mooij, J.E.
College/School:College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
Journal Name:Superconductor Science and Technology
Publisher:IOP Publishing
ISSN:0953-2048
ISSN (Online):1361-6668
Copyright Holders:Copyright © 2016 IOP Publishing Ltd
First Published:First published in Superconductor Science and Technology 30(2): 025002
Publisher Policy:Reproduced in accordance with the publisher copyright policy

University Staff: Request a correction | Enlighten Editors: Update this record