Reduction of low-frequency 1/f noise in Al-AlOx-Al tunnel junctions by thermal annealing

Abstract

We report that annealing Al-AlOx-Al tunnel junctions in a vacuum chamber at temperature of 400C reduces the characteristic 1/f noise in the junctions, in some cases by an order of magnitude. Both ultra high vacuum and high vacuum fabricated samples demonstrated a significant reduction in the 1/f noise level. Temperature dependence of the noise was studied between 4.2 and 340 Kelvin, with a linear dependence below 100 K, but a faster increase above. The results are consistent with a model where the density of charge trapping two level-systems within the tunneling barrier is reduced by the annealing process.

References in corpus (9)

• Opportunities for mesoscopics in thermometry and refrigeration: Physics and applications
• Decoherence in Josephson Qubits from Dielectric Loss
• Decoherence in a superconducting quantum bit circuit
• Decoherence in Josephson-junction qubits due to critical current fluctuations
• Temperature square dependence of the low frequency 1/f charge noise in the Josephson junction qubits
• Oxygen stoichiometry and instability in aluminium oxide tunnel barrier layers
• Low-frequency Noise in Josephson Junctions for Superconducting Qubits
• Complete stabilization and improvement of the characteristics of tunnel junctions by thermal annealing
• Microscopic origin of critical current fluctuations in large, small and ultra-small area Josephson junctions

Cited by in corpus (6)

• Fabrication of stable and reproducible sub-micron tunnel junctions
• Merged-Element Transmons: Design and Qubit Performance
• Optimization of $Al/Al{O}_x/Al$-Layer Systems for Josephson Junctions from a Microstructure Point of View
• Low frequency resistance and critical current fluctuations in Al-based Josephson junctions
• Universality of transport properties of ultra-thin oxide films
• Aluminum Josephson junction microstructure and electrical properties modification with thermal annealing