Ultralow-power coherent qubit control using AQFP logic at millikelvin temperatures

TL;DR

This paper introduces an ultralow-power, multiplexed qubit controller using AQFP logic that operates at millikelvin temperatures, enabling scalable superconducting quantum processors with minimal cooling impact.

Contribution

It presents the first implementation of an AQFP-based qubit controller capable of parallel qubit control at 10 mK with ultralow power dissipation and multiplexing.

Findings

Achieved qubit control with 111 pW power per qubit.

Demonstrated coherent single-qubit gates at 10 mK.

Enabled parallel control of multiple qubits with few control lines.

Abstract

Qubit controllers are essential for scaling superconducting quantum processors, but implementing them at the 10 mK stage of a dilution refrigerator remains challenging due to stringent cooling constraints. Here we report an ultralow-power qubit controller using adiabatic quantum-flux-parametron (AQFP) logic, termed an AQFP-multiplexed qubit controller with virtual Z gates (AQFP QC-VZ). The AQFP QC-VZ generates multi-tone microwave pulses for qubit control with an ultralow power dissipation of 111 pW per qubit. By combining microwave and time-division multiplexing, the AQFP QC-VZ enables parallel application of X and virtual Z gates to multiple qubits using only a few control lines from room temperature. We demonstrate coherent single-qubit gates at the 10 mK stage using an AQFP mixer, a core component of the AQFP QC-VZ, without observable degradation in coherence.