Q-IRIS: The Evolution of the IRIS Task-Based Runtime to Enable Classical-Quantum Workflows

TL;DR

This paper introduces a hybrid runtime framework that integrates classical and quantum workloads, demonstrating asynchronous execution and improved quantum simulation throughput in heterogeneous high-performance computing systems.

Contribution

It presents a novel proof-of-concept framework combining IRIS and XACC for orchestrating classical and quantum tasks across diverse backends, including quantum circuit cutting techniques.

Findings

Successful asynchronous scheduling of multiple quantum workloads

Quantum circuit cutting reduces simulation load and improves throughput

Framework demonstrates practical integration of classical and quantum runtimes

Abstract

Extreme heterogeneity in emerging HPC systems are starting to include quantum accelerators, motivating runtimes that can coordinate between classical and quantum workloads. We present a proof-of-concept hybrid execution framework integrating the IRIS asynchronous task-based runtime with the XACC quantum programming framework via the Quantum Intermediate Representation Execution Engine (QIR-EE). IRIS orchestrates multiple programs written in the quantum intermediate representation (QIR) across heterogeneous backends (including multiple quantum simulators), enabling concurrent execution of classical and quantum tasks. Although not a performance study, we report measurable outcomes through the successful asynchronous scheduling and execution of multiple quantum workloads. To illustrate practical runtime implications, we decompose a four-qubit circuit into smaller subcircuits through a process known as quantum circuit cutting, reducing per-task quantum simulation load and demonstrating how task granularity can improve simulator throughput and reduce queueing behavior -- effects directly relevant to early quantum hardware environments. We conclude by outlining key challenges for scaling hybrid runtimes, including coordinated scheduling, classical-quantum interaction management, and support for diverse backend resources in heterogeneous systems.