Millikelvin temperature cryo-CMOS multiplexer for scalable quantum device characterisation

Quantum computers based on solid state qubits have been a subject of rapid development in recent years. In current Noisy Intermediate-Scale (NISQ) technology, each quantum device is controlled and characterised though dedicated signal line between room temperature base dilution refrigerator. This approach not scalable currently limiting the large-scale system integration characterisation. Here we demonstrate custom designed cryo-CMOS multiplexer operating at 32 mK. The exhibits excellent microwave properties up to 10 GHz millikelvin temperatures. We increased characterisation throughput with by measuring four high-quality factor superconducting resonators using single input output Our work lays foundation for has perspective address wiring problem future computers.