Granthi: Higher-Order Quantum Programming via Unitary Wiring

Quantum Physics arXiv:2608.20443 (quant-ph) [Submitted on 20 Aug 2026] Title:Granthi: Higher-Order Quantum Programming via Unitary Wiring Authors:Samson Abramsky, Radha Jagadeesan View a PDF of the paper titled Granthi: Higher-Order Quantum Programming via Unitary Wiring, by Samson Abramsky and Radha Jagadeesan View PDF HTML (experimental) Abstract:Existing quantum programming languages confine higher order structure to a classical host while restricting the quantum layer to first order operations on qubits. This paper presents Granthi, a purely unitary higher-order quantum programming language built on three design commitments: quantum programs are first class values that may be passed, returned, and coherently composed; additive structure is tag-preserving routing rather than observational branching, so control may remain in superposition; and programmer-facing finite label types with named reversible operations provide domain-level control spaces without exposing tag management. Every well-typed term, including at function type, denotes a unitary on its boundary interface, and the compiler realizes exactly its wiring as a quantum circuit on the physical qubit layout (assuming correctness of the pytket backend). Granthi is implemented end-to-end: an OCaml DSL elaborates surface programs through a binder-free core IR to executable quantum circuits via pytket. The language directly supports the quantum switch, compiled to a static circuit, as well as interference on control-flow history and structured finite control, all within the purely unitary fragment. Comments: Subjects: Quantum Physics (quant-ph); Emerging Technologies (cs.ET); Logic in Computer Science (cs.LO); Programming Languages (cs.PL) Cite as: arXiv:2608.20443 [quant-ph] (or arXiv:2608.20443v1 [quant-ph] for this version) https://doi.org/10.48550/arXiv.2608.20443 Focus to learn more arXiv-issued DOI via DataCite Submission history From: Radha Jagadeesan [view email] [v1] Thu, 20 Aug 2026 15:49:09 UTC (140 KB) Full-text links: Access Paper: View a PDF of the paper titled Granthi: Higher-Order Quantum Programming via Unitary Wiring, by Samson Abramsky and Radha JagadeesanView PDFHTML (experimental)TeX Source view license Current browse context: quant-ph new | recent | 2026-08 Change to browse by: cs cs.ET cs.LO cs.PL References & Citations INSPIRE HEP NASA ADSGoogle Scholar Semantic Scholar export BibTeX citation Loading... BibTeX formatted citation × loading... Data provided by: Bookmark Bibliographic Tools Bibliographic and Citation Tools Bibliographic Explorer Toggle Bibliographic Explorer (What is the Explorer?) Connected Papers Toggle Connected Papers (What is Connected Papers?) Litmaps Toggle Litmaps (What is Litmaps?) scite.ai Toggle scite Smart Citations (What are Smart Citations?) Code, Data, Media Code, Data and Media Associated with this Article alphaXiv Toggle alphaXiv (What is alphaXiv?) Links to Code Toggle CatalyzeX Code Finder for Papers (What is CatalyzeX?) DagsHub Toggle DagsHub (What is DagsHub?) GotitPub Toggle Gotit.pub (What is GotitPub?) Huggingface Toggle Hugging Face (What is Huggingface?) ScienceCast Toggle ScienceCast (What is ScienceCast?) Demos Demos Replicate Toggle Replicate (What is Replicate?) Spaces Toggle Hugging Face Spaces (What is Spaces?) Spaces Toggle TXYZ.AI (What is TXYZ.AI?) Related Papers Recommenders and Search Tools Link to Influence Flower Influence Flower (What are Influence Flowers?) Core recommender toggle CORE Recommender (What is CORE?) Author Venue Institution Topic About arXivLabs arXivLabs: experimental projects with community collaborators arXivLabs is a framework that allows collaborators to develop and share new arXiv features directly on our website. Both individuals and organizations that work with arXivLabs have embraced and accepted our values of openness, community, excellence, and user data privacy. arXiv is committed to these values and only works with partners that adhere to them. Have an idea for a project that will add value for arXiv's community? Learn more about arXivLabs. Which authors of this paper are endorsers? | Disable MathJax (What is MathJax?)