Low-noise amplification at microwave frequencies has become increasingly important for the research related to superconducting qubits and nanoelectromechanical systems. The fundamental limit of added noise by a phase-preserving amplifier is the standard quantum limit, often expressed as noise temperature Tq = ℏω/2kB. Towards the goal of the quantum limit, we have developed an amplifier based on intrinsic negative resistance of a selectively damped Josephson junction. Here we present measurement results on previously proposed wide-band microwave amplification and discuss the challenges for improvements on the existing designs. We have also studied flux-pumped metamaterial-based parametric amplifiers, whose operating frequency can be widely tuned by external DC-flux, and demonstrate operation at 2 ω pumping, in contrast to the typical metamaterial amplifiers pumped via signal lines at ω. © 2014 Springer Science+Business Media New York.
CITATION STYLE
Lähteenmäki, P., Vesterinen, V., Hassel, J., Paraoanu, G. S., Seppä, H., & Hakonen, P. (2014). Advanced concepts in josephson junction reflection amplifiers. Journal of Low Temperature Physics, 175(5–6), 868–876. https://doi.org/10.1007/s10909-014-1170-0
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