Approximate Error Correction for Quantum Simulations of SU(2) Lattice Gauge Theories

Quantum Physics [Submitted on 26 Mar 2026] Approximate Error Correction for Quantum Simulations of SU(2) Lattice Gauge Theories Zachary P. Bradshaw We present a protocol for actively suppressing Gauss law violations in quantum simulations of SU(2) lattice gauge theory. The protocol uses mid-circuit measurements to extract a characterization of the gauge-violation sector at each lattice vertex, resolving both the total angular momentum and magnetic quantum numbers of the violation via a group quantum Fourier transform. Syndrome-conditional recovery operations map the state back to the gauge-invariant subspace through an iterative sweep over vertices, a procedure we call gauge cooling. We show that while the Knill-Laflamme conditions are not generically satisfied at vertices with nontrivial singlet multiplicity, every single-qubit error is detected by the gauge syndrome. We demonstrate gauge cooling on a single-plaquette simulation of the Kogut-Susskind Hamiltonian truncated to the spin-1/2 representation under depolarizing and amplitude damping noise, showing that the protocol restores gauge invariance and improves fidelity at noise rates representative of current superconducting hardware. Comments: 16 pages, 1 figure Subjects: Quantum Physics (quant-ph); High Energy Physics - Lattice (hep-lat) MSC classes: 81P73 (Primary) 81T13 (Secondary) Cite as: arXiv:2603.26819 [quant-ph]   (or arXiv:2603.26819v1 [quant-ph] for this version)   https://doi.org/10.48550/arXiv.2603.26819 Focus to learn more Submission history From: Zachary Bradshaw [view email] [v1] Thu, 26 Mar 2026 21:43:47 UTC (53 KB) Access Paper: view license Current browse context: quant-ph < prev   |   next > new | recent | 2026-03 Change to browse by: hep-lat References & Citations INSPIRE HEP NASA ADS Google Scholar Semantic Scholar Export BibTeX Citation 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 Demos Related Papers About arXivLabs Which authors of this paper are endorsers? | Disable MathJax (What is MathJax?)