Abstract
We present experimental results for a Josephson parametric amplifier tailored for readout of ultra-sensitive thermal microwave detectors. In particular, we discuss the impact of fabrication details on the performance. We show that the small volume of deposited dielectric materials enabled by the side-wall passivated spacer niobium junction technology leads to robust operation across a wide range of operating temperatures up to 1.5 K. The flux-pumped amplifier has gain in excess of 20 dB in three-wave mixing and its center frequency is tunable between 540-640 MHz. At 600 MHz, the amplifier adds 105 mK 9 mK of noise, as determined with the hot/cold source method. Phase-sensitive amplification is demonstrated with the device.
Original language | English |
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Article number | 105001 |
Journal | Superconductor Science and Technology |
Volume | 31 |
Issue number | 10 |
DOIs | |
Publication status | Published - 24 Aug 2018 |
MoE publication type | A1 Journal article-refereed |
Funding
This work was performed as part of the Academy of Finland Centre of Excellence program (projects 312294, 284594, 312059, 251748, and 284621). The work also received funding from the Academy of Finland project QuMOS (project numbers 288907 and 287768), Future Makers Funding Program by Technology Industries of Finland Centennial Foundation and Jane and Aatos Erkko Foundation.
Keywords
- Josephson junction
- parametric amplifier
- SQUID array