Experimental validation of a compact fault-tolerant architecture for trapped ions

Quantum Physics arXiv:2609.03194 (quant-ph) [Submitted on 2 Sep 2026] Title:Experimental validation of a compact fault-tolerant architecture for trapped ions Authors:Noah Berthusen, Ali Lavasani, Asmae Benhemou, M.S. Allman, Joan Dreiling, Brian Estey, Cameron Foltz, Trent Jacobs, Michael Mills, Annie Jihyun Park, Adam P. Reed, David Hayes, Tzvetan S. Metodi, Andrew C. Potter View a PDF of the paper titled Experimental validation of a compact fault-tolerant architecture for trapped ions, by Noah Berthusen and Ali Lavasani and Asmae Benhemou and M.S. Allman and Joan Dreiling and Brian Estey and Cameron Foltz and Trent Jacobs and Michael Mills and Annie Jihyun Park and Adam P. Reed and David Hayes and Tzvetan S. Metodi and Andrew C. Potter View PDF Abstract:Quantum error correction (QEC) is beginning to enable logical operations that outperform their unencoded physical counterparts, but useful fault-tolerant computation will require more than low-error quantum memory. An effective architecture must orchestrate efficient logical encoding, low-overhead logical operations, and access to the non-Clifford resources required for universal computation. Here, we introduce and experimentally validate such an architecture based on the $[[20,2,6]]$ $C_4$-Helix code, designed for the early fault-tolerant regime.

Using Quantinuum Helios, a 98-qubit trapped-ion quantum processor, we experimentally demonstrate the principal components of this architecture: we perform repeated quantum error correction with an error of $4.6^{+6.2}_{-2.6}\times10^{-5}$ per logical qubit per QEC cycle. We benchmark the complete Clifford group on the two logical qubits of a single codeblock under active error correction, obtaining an error of $2.8^{+1.0}_{-1.6}\times 10^{-4}$ per two-qubit logical Clifford. We further demonstrate a fault-tolerant chain-map interface between $C_4$-Helix and a distance-5 surface code, preparing a heterogeneous three-logical-qubit GHZ state with a fidelity lower bound of $99.925^{+0.068}_{-0.245}\%$. In each case, the encoded implementation outperforms its corresponding unencoded physical baseline without relying on postselection. Circuit-level simulations indicate that improvements in physical fidelity bring the same architecture into the $10^{-6}$-$10^{-8}$ logical-error regime targeted for early fault-tolerant computation. Together, these results establish $C_4$-Helix as a hardware-validated fault-tolerant architecture rather than a bare quantum memory. Comments: Subjects: Quantum Physics (quant-ph) Cite as: arXiv:2609.03194 [quant-ph] (or arXiv:2609.03194v1 [quant-ph] for this version) https://doi.org/10.48550/arXiv.2609.03194 Focus to learn more arXiv-issued DOI via DataCite (pending registration) Submission history From: Noah Berthusen [view email] [v1] Wed, 2 Sep 2026 22:21:23 UTC (9,720 KB) Full-text links: Access Paper: View a PDF of the paper titled Experimental validation of a compact fault-tolerant architecture for trapped ions, by Noah Berthusen and Ali Lavasani and Asmae Benhemou and M.S. Allman and Joan Dreiling and Brian Estey and Cameron Foltz and Trent Jacobs and Michael Mills and Annie Jihyun Park and Adam P. Reed and David Hayes and Tzvetan S. Metodi and Andrew C. PotterView PDFTeX Source view license Current browse context: quant-ph new | recent | 2026-09 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?)