Elimination of two level fluctuators in superconducting quantum bits by an epitaxial tunnel barrier

Published

September 7, 2006

Author(s)

Seongshik Oh, Katarina Cicak, Jeffrey S. Kline, Mika Sillanpaa, Jed D. Whittaker, Raymond W. Simmonds, David P. Pappas, Kevin Osborn

Abstract

Quantum computing based on Josephson junction technology is considered promising due to its scalable architecture. However, decoherence is a major obstacle. Here, we report evidence for improved Josephson quantum bits qubits using a single-crystal Al2O3 tunnel barrier. We have found an 80% reduction in the density of the spectral splittings that indicate the existence of two-level fluctators TLFs in amorphous tunnel barriers. The residual 20% TLFs can be attributed to interfacial effects that may be further reduced by different electrode materials. These results show that decoherence sources in the tunnel barrier of Josephson qubits can be identified and eliminated.

Citation

Nature Materials

Volume

74

Issue

10

Pub Type

Journals

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Keywords

epitaxial barrier, Josephoson junction, Quantum bit, tunnel junction

Citation

Oh, S. , Cicak, K. , Kline, J. , Sillanpaa, M. , Whittaker, J. , Simmonds, R. , Pappas, D. and Osborn, K. (2006), Elimination of two level fluctuators in superconducting quantum bits by an epitaxial tunnel barrier, Nature Materials, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=32352 (Accessed October 14, 2025)