A Scalable Multi-Channel Cryogenic Controller for Spin Qubits/Transmons with Frequency Multiplexing Capability Implemented in Intel 22nm FinFET Technology

Scaling a fault-tolerant quantum computer to a very large number of qubits is a daunting challenge. Innovation is required in qubit fabrication, integration and control. Current approaches for controlling qubits operating at cryogenic temperature using room-temperature electronics will not scale to large qubit arrays. We have recently proposed to bring integrated electronics close to the qubits at cryogenic temperatures. Leveraging deeply-scaled CMOS process technologies, complex System-on-Chips (SoCs) with digital, analog and RF capabilities can be integrated with sufficiently low power consumption to be compatible with dilution refrigerators. We demonstrate a cryo-CMOS controller SoC designed to operate at 4K and implemented in Intel 22nm FinFET technology. The SoC is capable of addressing 128 frequency-multiplexed qubits across 4 separate channels over 1GHz RF bandwidth from 2 to 20GHz. The maximum output power is -16dBm at 6GHz with 40dB gain control. Such flexibility enables the control of both spin qubits and transmons with the same chip. By operating our cryo-CMOS controller on the 4K plate in a dilution refrigerator also hosting a Si-based qubit sample at 20mK, we demonstrate Rabi oscillations and coherent x-y rotations of the spin qubit at both 13.7 and 17.5GHz.