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Correlating the nanostructure of Al-oxide with deposition conditions and dielectric contributions of two-level systems in perspective of superconducting quantum circuits

Fritz, S.; Seiler, A.; Radtke, L.; Schneider, R.; Weides, M.; Weiß, G.; Gerthsen, D.

This work is concerned with Al/Al-oxide(AlOx)/Al-layer systems which are important for Josephson-junction-based superconducting devices such as quantum bits. The device performance is limited by noise, which has been to a large degree assigned to the presence and properties of two-level tunneling systems in the amorphous AlOx tunnel barrier. The study is focused on the correlation of the fabrication conditions, nanostructural and nanochemical properties and the occurrence of two-level tunneling systems with particular emphasis on the AlOx-layer. Electron-beam evaporation with two different processes and sputter deposition were used for structure fabrication, and the effect of illumination by ultraviolet light during Al-oxide formation is elucidated. Characterization was performed by analytical transmission electron microscopy and low-temperature dielectric measurements. We show that the fabrication conditions have a strong impact on the nanostructural and nanochemical properties of the layer systems and the properties of two-level tunneling systems. Based on the understanding of the observed structural characteristics, routes are suggested towards the fabrication of Al/AlOx/Al-layers systems with improved properties.

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Verlagsausgabe §
DOI: 10.5445/IR/1000083372
Veröffentlicht am 12.06.2018
DOI: 10.1038/s41598-018-26066-4
Zitationen: 3
Web of Science
Zitationen: 3
Cover der Publikation
Zugehörige Institution(en) am KIT Laboratorium für Elektronenmikroskopie (LEM)
Physikalisches Institut (PHI)
Publikationstyp Zeitschriftenaufsatz
Publikationsmonat/-jahr 12.2018
Sprache Englisch
Identifikator ISSN: 2045-2322
KITopen-ID: 1000083372
Erschienen in Scientific reports
Band 8
Heft 1
Seiten 7956/1-11
Bemerkung zur Veröffentlichung Gefördert durch den KIT-Publikationsfonds
Vorab online veröffentlicht am 21.05.2018
Nachgewiesen in Scopus
Web of Science
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