  The control interface of a large-scale quantum computer will likely require
electronic sub-systems that operate in close proximity to the qubits, at deep
cryogenic temperatures. Here, we report the low-temperature performance of
custom cryo-CMOS band-gap reference circuits designed to provide stable
voltages and currents on-chip, independent of local temperature fluctuations.
Our circuits are fabricated in 0.35 um silicon Germanium (SiGe) BiCMOS and 28
nm Fully Depleted Silicon On Insulator (FDSOI) CMOS processes, and we compare
the performance of each. Beyond their specific application as low-power
references, these circuits are ideal test-vehicles for developing design
approaches that mitigate the adverse effects of cryogenic temperatures on
circuit performance.
