Programmable and scalable radio-frequency pulse sequence generator for multi-qubit quantum information experiments

TL;DR

This paper introduces a scalable, programmable RF pulse generator system for multi-qubit quantum experiments, capable of producing precise pulse sequences across multiple channels and frequencies, supporting real-time updates and synchronization.

Contribution

The authors present a versatile, multi-channel RF control system with real-time programmability and synchronization, extending frequency range and supporting various quantum platforms.

Findings

Achieved high-fidelity quantum gates meeting fault-tolerance thresholds

Extended RF control to gigahertz frequencies for atomic systems

Demonstrated system's effectiveness in trapped-ion quantum experiments

Abstract

We present a versatile rf pulse control system that has been designed for multi-qubit quantum experiments. One instrument can be scaled to provide 32 channels of rf between 10 - 450 MHz. Synchronization can be achieved across multiple instruments. By using direct digital synthesis and custom control circuitry contained within a field-programmable gate array, sequences of transform-limited pulses can be produced. These have been used to carry out quantum gates that are able to meet fault-tolerant thresholds for single- and two-qubit gate fidelities, as published elsewhere. We have also extended the frequency to the gigahertz regime using additional mixers to address hyperfine transitions in atomic systems. The system uses an efficient memory management scheme and a low-latency communications protocol that allows pulse sequences to be updated in real-time. Together these can enable outcome-based algorithms such as quantum error correction to be executed. The system is fully programmable in C++, and other languages such as Python can be supported by the on-board CPU, offering a highly flexible platform for a wide variety of experimental systems, and has been proven in trapped-ion quantum information experiments.