Oral Presentation

Cryo-CMOS circuits for qubit control and readout

Author(s): Jiun-Yun Li (Department of Electrical Engineering, National Taiwan University)

Presenter: Jiun-Yun Li (Department of Electrical Engineering, National Taiwan University)

Quantum computing is becoming a reality from a science hype in the past decade. To realize a working quantum computer, millions of quantum bits (qubits) are required to execute error corrections. While much progress has been made on the qubit number and fidelity, control systems by connecting long wires from room-temperature electronics to the qubits at few millikelvins in a dilution fridge could leads to signal latency, heating, and noise as the qubits are further scaled up. To resolve this issue, cryo-CMOS circuits have been proposed by placing the control and readout circuitry into a fridge to reduce the signal loss and mitigate the issues by long wires using room-temperature electronics. In this work, I will introduce the development of cryo-CMOS circuits to interface with transmon qubits. We’ve characterized CMOS devices at cryogenic temperatures and build parameters for SPICE modeling and successfully demonstrated the cryogenic operations of the following circuits: digital-to-analog conversion (DACs), oscillators, radio-frequency (RF) driver/amplifiers, and low-noise amplifiers (LNAs). We were able to demonstrate few significant breakthroughs on ultrawide-bandwidth LNAs (~ 4 GHz), signal generation of ultrahigh frequency (~ 30 GHz), high-performance DACs with SFDR of > 70 dB, and an extremely low power electronic switch to increase the characterization speed of cryogenic measurements.