Deterministic linear-optical computing with symmetry-based qubits

Quantum Physics [Submitted on 8 Apr 2026] Deterministic linear-optical computing with symmetry-based qubits David S. Simon, Christopher R. Schwarze, Anthony D. Manni, Abdoulaye Ndao, Alexander V. Sergienko A particular type of linear optical multiport, the Grover four-port, has previously been shown to couple the spatial symmetry of a photon to its direction of travel. It is shown here that use of a nonstandard choice of qubit, based on symmetry, allows Grover four ports to act as compact, low-resource deterministic linear optical controlledNOTgates, with no post-selection or ancilla measurements required. This approach allows programmable devices, made from Grover multiports in combination with other standard optical components, that can implement multiple different one-, two-, and three-qubit gates, including the Fredkin and Toffoli gates. Subjects: Quantum Physics (quant-ph) Cite as: arXiv:2604.06584 [quant-ph]   (or arXiv:2604.06584v1 [quant-ph] for this version)   https://doi.org/10.48550/arXiv.2604.06584 Focus to learn more Journal reference: Quantum Information Processing 25, 136 (2026) Related DOI: https://doi.org/10.1007/s11128-026-05157-6 Focus to learn more Submission history From: David Simon [view email] [v1] Wed, 8 Apr 2026 02:12:17 UTC (452 KB) Access Paper: HTML (experimental) view license Current browse context: quant-ph < prev   |   next > new | recent | 2026-04 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?)