A Cryogenic Variable Temperature Microwave Noise Source
ORAL
Abstract
We present a cryogenic microwave noise source with a characteristic impedance of 50 Ω designed to be installed in a coaxial line of a cryostat [1]. The bath temperature of the noise source is continuously variable between 0.1 K and 5 K without causing significant heating on the sample space. As a proof-of-concept experiment, we performed Y-factor measurements of an amplifier cascade that includes a traveling wave parametric amplifier and a commercial high electron mobility transistor amplifier. We observed system noise temperatures as low as 680+20-200 mK at 5.7 GHz corresponding to 1.5+0.1 -0.7 excess photons. The device we present has immediate applications in the characterization of solid-state qubit readout lines.
References: [1] S. Simbierowicz et al., arXiv:2009.03010 [quant-ph] (2020).
References: [1] S. Simbierowicz et al., arXiv:2009.03010 [quant-ph] (2020).
*V.V., L.G., and J.H. acknowledge financial support from the Academy of Finland through its Centers of Excellence Program (project nos. 312059 and 312294) and grant no. 321700, and from the EU Flagship on Quantum Technology H2020-FETFLAG-2018-03 project 820363 OpenSuperQ.
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Presenters
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Slawomir Simbierowicz
- VTT Technical Research Centre of Finland Ltd
- Bluefors Oy
- VTT Micro & Nanoelectronics