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Overlap junctions for superconducting quantum electronics and amplifiers



Mustafa Bal, Junling Long, Ruichen Zhao, Haozhi Wang, Sungoh Park, Corey Rae H. McRae, Tongyu Zhao, Russell Lake, Daniil Frolov, Roman Pilipenko, Silvia Zorzetti, Alexander Romanenko, David P. Pappas


Due to their unique properties as lossless, nonlinear circuit elements, Josephson junctions lie at the heart of superconducting quantum information processing. Previously, we demonstrated a two-layer, submicrometer-scale overlap junction fabrication process suitable for qubits with long coherence times. Here, we extend the overlap junction fabrication process to micrometer-scale junctions. This allows us to fabricate other superconducting quantum devices. For example, we demonstrate an overlap-junction-based Josephson parametric amplifier that uses only 2 layers. This efficient fabrication process yields frequency-tunable devices with negligible insertion loss and a gain of ~ 30 dB. Compared to other processes, the overlap junction allows for fabrication with minimal infrastructure, high yield, and state-of-the-art device performance.
Applied Physics Letters


lossless, nonlinear circuit elements, Josephson junctions, superconducting quantum information processing, two-layer, submicrometer-scale overlap junction fabrication, qubits, long coherence times, micrometer-scale junctions, frequency-tunable devices, state-of-the-art device performance


Bal, M. , Long, J. , Zhao, R. , Wang, H. , Park, S. , H., C. , Zhao, T. , Lake, R. , Frolov, D. , , R. , , S. , Romanenko, A. and Pappas, D. (2020), Overlap junctions for superconducting quantum electronics and amplifiers, Applied Physics Letters, [online], (Accessed March 2, 2024)
Created May 24, 2020, Updated July 10, 2020