Microwave-multiplexed qubit controller using adiabatic superconductor logic

TL;DR

This paper introduces a scalable cryogenic qubit controller using ultra-low-power adiabatic superconductor logic, enabling microwave multiplexing to efficiently control large-scale superconducting quantum processors with minimal power dissipation.

Contribution

The paper presents the first implementation of an AQFP-based multiplexed qubit controller capable of generating microwave signals with extremely low power consumption and reduced cabling via microwave multiplexing.

Findings

Demonstrated microwave multiplexing and demultiplexing with two output ports.

Achieved output power of approximately -80 dBm and 40 dB on/off ratio.

Validated basic mixing operation through sideband signals.

Abstract

Cryogenic qubit controllers (QCs) are the key to build large-scale superconducting quantum processors. However, developing scalable QCs is challenging because the cooling power of a dilution refrigerator is too small (~10 $\mu$W at ~10 mK) to operate conventional logic families, such as complementary metal-oxide-semiconductor logic and superconducting single-flux-quantum logic, near qubits. Here we report on a scalable QC using an ultra-low-power superconductor logic family, namely adiabatic quantum-flux-parametron (AQFP) logic. The AQFP-based QC, referred to as the AQFP-multiplexed QC (AQFP-mux QC), produces multi-tone microwave signals for qubit control with an extremely small power dissipation of 81.8 pW per qubit. Furthermore, the AQFP-mux QC adopts microwave multiplexing to reduce the number of coaxial cables for operating the entire system. As a proof of concept, we demonstrate an AQFP-mux QC chip that produces microwave signals at two output ports through microwave multiplexing and demultiplexing. Experimental results show an output power of approximately $-$80 dBm and on/off ratio of ~40 dB at each output port. Basic mixing operation is also demonstrated by observing sideband signals.