Atomic structure and oxygen deficiency of the ultrathin aluminium oxide barrier in Al/AlOx/Al Josephson junctions
Artikel i vetenskaplig tidskrift, 2016

Al/AlOx/Al Josephson junctions are the building blocks of a wide range of superconducting quantum devices that are key elements for quantum computers, extremely sensitive magnetometers and radiation detectors. The properties of the junctions and the superconducting quantum devices are determined by the atomic structure of the tunnel barrier. The nanoscale dimension and disordered nature of the barrier oxide have been challenges for the direct experimental investigation of the atomic structure of the tunnel barrier. Here we show that the miniaturized dimension of the barrier and the interfacial interaction between crystalline Al and amorphous AlOx give rise to oxygen deficiency at the metal/oxide interfaces. In the interior of the barrier, the oxide resembles the atomic structure of bulk aluminium oxide. Atomic defects such as oxygen vacancies at the interfaces can be the origin of the two-level systems and contribute to decoherence and noise in superconducting quantum circuits.

superconducting qubits

Science & Technology - Other Topics

elnes

scattering

al2o3

2-level systems

nanovolumes

decoherence

coordination

amorphous materials

Författare

Lunjie Zeng

Chalmers, Fysik, Eva Olsson Group

D. T. Tran

Stockholms universitet

C. W. Tai

Stockholms universitet

G. Svensson

Stockholms universitet

Eva Olsson

Chalmers, Fysik, Eva Olsson Group

Scientific Reports

2045-2322 (ISSN)

Vol. 6 29679

Ämneskategorier

Fysik

DOI

10.1038/srep29679

PubMed

27403611