Overlap junction-based Josephson parametric amplifiers (O-JPA)

We have recently developed submicron scale overlap Josephson junction fabrication process suitable for superconducting qubits with long coherence times [1]. Here, we extend the fab process to micron scale overlap junctions to enable other superconducting quantum devices such as overlap junction-based Josephson parametric amplifiers (O-JPA). We realize frequency tunable O-JPAs with negligible insertion loss. Compared to other competing processes, overlap junction process for micron scale junctions allows the fabrication of O-JPAs with high yield and good device performance at a much lower infrastructure requirements. We present the fabrication details as well as the characterization of O-JPAs.

[1] X. Wu, J. L. Long, H. S. Ku, R. E. Lake, M. Bal, and D. P. Pappas, “Overlap junctions for high coherence superconducting qubits”, Appl. Phys. Lett. 111, 032602 (2017).