We present a lumped-element Josephson parametric amplifier (JPA) utilizing a straightforward fabrication process involving a single electron beam lithography step followed by double-angle evaporation of aluminum and in-situ oxidation. The Josephson junctions forming the SQUID are fabricated using bridgeless shadow evaporation technique, which enables reliable fabrication of relatively large (∼9μm2) junctions. Our strongly coupled flux-pumped JPA achieves 20~dB gain with 95~MHz bandwidth around 5~GHz, while the center frequency is tunable by more than 1~GHz, with the additional possibility for rapid tuning by varying the pump frequency alone. Analytical calculations based on the input-output theory reproduce our measurement results closely.
@article{arxiv.1812.07621,
title = {Broadband lumped-element Josephson parametric amplifier with single-step lithography},
author = {T. Elo and T. S. Abhilash and M. R. Perelshtein and I. Lilja and E. V. Korostylev and P. J. Hakonen},
journal= {arXiv preprint arXiv:1812.07621},
year = {2019}
}