A 1.6-mW Cryogenic SiGe LNA IC for Quantum Readout Applications Achieving 2.6-K Average Noise Temperature From 3 to 6 GHz

Readout of superconducting quantum processors of sufficient scale to enable useful fault-tolerant quantum computing will require large arrays of high-performance cryogenic low-noise amplifiers. While it is desirable to employ silicon-based integrated-circuit amplifiers for this application, to date, the noise performance of such devices has been significantly worse than that of amplifiers implemented in III-V technologies. Here, we present the design and characterization of a high-gain cryogenic SiGe LNA IC achieving an average noise temperature of 2.6 K over the 3-6-GHz frequency band while dissipating just 1.6 mW. To the best of our knowledge, this amplifier achieves the best performance of any silicon-based LNA (discrete or integrated circuit) operating in this frequency range.