Cryo-CMOS Systems and Circuits for Large-Scale Quantum Computers

Today’s quantum processors can be controlled by conventional electronics working at room temperature, as only a few electrical signals must be wired to and from the few available qubits. However, as practical quantum computers will require an aggressive scaling up of the number of qubits, this approach will become impractical. A more scalable approach requires operating a complex electronic interface at cryogenic temperature, very close to the quantum processor, eventually in the same package or even on the same chip. Thanks to its high integration capabilities, CMOS is the most viable technology for such a cryogenic interface. In this talk, we will review several state-of-the-art cryo-CMOS circuits and systems, both for qubit drive and readout, including high-speed analog-to-digital converters, low-noise amplifiers and microwave generators, demonstrating their electrical performance and their capability to operate in the field with real qubits. This will show how the capabilities of the CMOS technology — the very large scale of integration (VLSI) combined with advanced digital processing and cutting-edge analog performance — can be exploited to build a comprehensive toolbox of components and functionalities, that will be instrumental to enable novel cryogenic systems and to realize future large-scale quantum computers.