Gain calibration of a cryogenic amplification chain using normal-metal–insulator–superconductor junctions
ORAL
Abstract
To achieve a high-efficiency readout in a low-temperature microwave circuit using both cryogenic and room temperature electronics, the signal has to go through one or more amplifiers to obtain a reasonable signal-to-noise ratio. In practice, the readout line has additional losses and reflections due to different microwave components which hinder the gain estimation.
We present a gain calibration scheme [1] that utilizes a normal-metal–insulator–superconductor junction, which is capacitively coupled to a superconducting microwave resonator [2]. Depending on the bias voltage applied to the junction, the nanostructure can be employed as a quantum-circuit refrigerator [3] or as an incoherent photon source [4]. For the latter case, we derive an analytic expression for the total gain that is based on only a single fitting parameter. We present our experimental results where we reach 0.1 dB relative uncertainty of the total gain in a three-stage amplification chain.
[1] - E. Hyyppä et al. Appl. Phys. Lett. 114, 192603 (2019)
[2] - M. Silveri et al. Phys. Rev. B 9, 96, 094524 (2017)
[3] - K. Y. Tan et al. Nat. Commun 8, 15189 (2017)
[4] - S. Masuda et al. Sci. Rep. 8, 3966 (2018)
We present a gain calibration scheme [1] that utilizes a normal-metal–insulator–superconductor junction, which is capacitively coupled to a superconducting microwave resonator [2]. Depending on the bias voltage applied to the junction, the nanostructure can be employed as a quantum-circuit refrigerator [3] or as an incoherent photon source [4]. For the latter case, we derive an analytic expression for the total gain that is based on only a single fitting parameter. We present our experimental results where we reach 0.1 dB relative uncertainty of the total gain in a three-stage amplification chain.
[1] - E. Hyyppä et al. Appl. Phys. Lett. 114, 192603 (2019)
[2] - M. Silveri et al. Phys. Rev. B 9, 96, 094524 (2017)
[3] - K. Y. Tan et al. Nat. Commun 8, 15189 (2017)
[4] - S. Masuda et al. Sci. Rep. 8, 3966 (2018)
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Presenters
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Máté Jenei
- QCD Labs, QTF Center of Excellence, Department of Applied Physics, Aalto University
- Department of Applied Physics, Aalto University