APS March Meeting 2024

Cryo-CMOS flux control generator for tunable transmons


In the last decade quantum gate fidelities have inched closer to error correcting thresholds, and the number of qubits per quantum processor have grown year over year. To sustain this growth, simultaneous advancements in quantum system hardware are also necessary. This implies the need for new and improved technologies to meet the scaling demands: performance, power, size, and cost. For qubit control electronics, CMOS technology provides a powerful set of capabilities and overall platform, due to the extent of design and fabrication resources supported by the semiconductor industry. Furthermore, when integrated at cryogenic temperatures, CMOS devices have the potential to address not only the scaling issues of power, size, and cost, but to also improve performance and reduce the fridge I/O; especially when compared to conventional electronics at room temperature. A key challenge in the development of scalable quantum control electronics is understanding how electronics noise gives rise to gate errors in the quantum processor. Here we evaluate the impact of electronics noise on flux tunable transmons controlled with a cryo-CMOS current generator, fabricated in 14nm FinFET technology, and thermalized to the T=4K plate of a dilution refrigerator. We evaluate the CMOS generated noise floor and correlate the noise with measurements of qubit dephasing as a function of flux bias sensitivity. Additionally, we investigate the potential of using a cryo-CMOS current generator for performing quantum gates.