A Scalable mK DC Demultiplexer With Extremely Low OFF-Leakage CMOS Switches for Biasing of Spin Qubits

This paper demonstrates a DC demultiplexer using CMOS switches with extremely low OFF-state current at mK temperatures. The DC demultiplexer is designed to reduce the number of interconnections needed for voltage biasing of large-scale spin qubit arrays. The demultiplexer utilizes a T-switch structure and thick-oxide devices in a 65nm bulk CMOS technology to avoid current leakage in the OFF-state of switches at mK temperatures, which enables preservation of a voltage stored on a capacitor without the need for resampling thereby reducing dynamic power consumption. The demultiplexer has a static power consumption of 33nW with 4 inputs and 16 outputs, which can be scaled up using the SPI interface of the demultiplexer in a daisy-chain configuration. With its scalability, ultra-low static power dissipation, and extremely low OFF-leakage current, the DC demultiplexer can help mitigate the wiring bottleneck of spin-based quantum computers at the base stage of dilution refrigerators.