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.