Performant coherent control: bridging the gap between high- and low-level operations on hardware

TL;DR

This paper introduces a scalable, automated control system for trapped-ion quantum computers that reduces calibration complexity, data bandwidth, and supports high-level feedback, enhancing system stability and performance.

Contribution

It presents a novel control hardware and embedded pulse compiler that automate calibration, compress data, and enable in-situ optimization for improved quantum system scalability.

Findings

Reduces calibration steps and manual bookkeeping

Decreases data transfer bandwidth via gate compression

Supports high-level algorithmic feedback and on-chip execution

Abstract

Scalable coherent control hardware for quantum information platforms is rapidly growing in priority as their number of available qubits continues to increase. As these systems scale, more calibration steps are needed, leading to challenges with system instability as calibrated parameters drift. Moreover, the sheer amount of data required to run circuits with large depth tends to balloon, especially when implementing state-of-the-art dynamical-decoupling gates which require advanced modulation techniques. We present a control system that addresses these challenges for trapped-ion systems, through a combination of novel features that eliminate the need for manual bookkeeping, reduction in data transfer bandwidth requirements via gate compression schemes, and other automated error handling techniques. Moreover, we describe an embedded pulse compiler that applies staged optimization, including compressed intermediate representations of parsed output products, performs in-situ mutation of compressed gate data to support high-level algorithmic feedback to account for drift, and can be run entirely on chip.