Comparing optical-microwave conversion and all-microwave control schemes for a transmon qubit

TL;DR

This study compares traditional microwave control with optical control for transmon qubits, finding no adverse effects on coherence and suggesting potential for scalable quantum computing systems.

Contribution

It provides the first direct comparison of optical and microwave control methods for transmon qubits, demonstrating optical control's viability without coherence degradation.

Findings

No measurable impact on qubit coherence from optical control

Optical control system shows comparable performance to microwave control

Supports potential for scalable quantum computing architectures

Abstract

We report a comparative study on transmon qubit control using (i) conventional attenuated coaxial microwave line and (ii) an optical control system using modulated laser light delivered over telecommunications optical fiber to a photodiode located at the 1K stage of a dilution cryostat. During each experiment, we performed repeated measurements of the energy relaxation and coherence times of a transmon qubit using one of the control signal delivery methods. Each measurement run spanned 20 hours of measurement time and from these datasets we observe no measurable effect on coherence of the qubit compared to random coherence fluctuations. Our results open up the possibility of large scale integration of the optical qubit control system.