HUGR: A Quantum-Classical Intermediate Representation
Abstract
We introduce the Hierarchical Unified Graph Representation (HUGR): a novel graph based intermediate representation for mixed quantum-classical programs. HUGR's design features high expressivity and extensibility to capture the capabilities of near-term and forthcoming quantum computing devices, as well as new and evolving abstractions from novel quantum programming paradigms. The graph based structure is machine-friendly and supports powerful pattern matching based compilation techniques. Inspired by MLIR, HUGR's extensibility further allows compilation tooling to reason about programs at multiple levels of abstraction, lowering smoothly between them. Safety guarantees in the structure including strict, static typing and linear quantum types allow rapid development of compilation tooling without fear of program invalidation. A full specification of HUGR and reference implementation are open-source and available online.
Cite
@article{arxiv.2510.11420,
title = {HUGR: A Quantum-Classical Intermediate Representation},
author = {Mark Koch and Agustín Borgna and Seyon Sivarajah and Alan Lawrence and Alec Edgington and Douglas Wilson and Craig Roy and Luca Mondada and Lukas Heidemann and Ross Duncan},
journal= {arXiv preprint arXiv:2510.11420},
year = {2025}
}
Comments
8 pages, extended abstract submitted to PlanQC25