A 6mW Cryogenic SiGe Receiver IC For High-Fidelity Qubit Readout

A SiGe BiCMOS cryogenic direct-conversion receiver operating at 4K is presented that demonstrates high-fidelity readout of a transmon qubit. Notably, at 6mW, this design demonstrates a readout fidelity greater than 98% in 1 mu s when preceded by a Josephson parametric amplifier with a gain of 15-18 dB. To the best of the authors' knowledge, this is the first system that entirely replaces an InP-HEMT LNA-based receiver chain with a silicon readout integrated circuit. This demonstration represents an important step in the realization of fully integrated, large-scale cryogenic qubit control systems.