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arXiv · 1805.07307

Flux-driven Josephson parametric amplifier for sub-GHz frequencies fabricated with side-wall passivated spacer junction technology

Slawomir Simbierowicz·Visa Vesterinen·Leif Grönberg·Janne Lehtinen·Mika Prunnila·Juha Hassel
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Abstract

We present experimental results on 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 MHz and 640 MHz. At 600 MHz, the amplifier adds 105 mK $\pm$ 9 mK of noise, as determined with the hot/cold source method. Phase-sensitive amplification is demonstrated with the device.

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Slawomir Simbierowicz, Visa Vesterinen, Leif Grönberg, Janne Lehtinen, Mika Prunnila, Juha Hassel. 2018-05-18. Flux-driven Josephson parametric amplifier for sub-GHz frequencies fabricated with side-wall passivated spacer junction technology. https://doi.org/10.1088/1361-6668/aad4f2

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