Linear-optical generation of hybrid GKP entanglement from small-amplitude cat states

Quantum Physics [Submitted on 20 Mar 2026] Linear-optical generation of hybrid GKP entanglement from small-amplitude cat states Shohei Kiryu, Yohji Chin, Masahiro Takeoka, Kosuke Fukui Hybrid bosonic codes combining bosonic codes with photon states offer a promising pathway for fault-tolerant quantum computation. However, the efficient generation of such states in optical setups remains technically challenging due to the requirement for complex non-Gaussian resources. In this paper, we propose a novel scheme to efficiently generate hybrid entangled states between a GKP qubit and a photon-number state using small-amplitude cat states as the primary resource. We apply a breeding process using small-amplitude cat states to increase the non-Gaussianity of the input states. This method requires only linear optical elements and homodyne measurements. Furthermore, we demonstrate that this protocol can be extended to generate hybrid qudit states. This scheme has the potential to provide a resource-efficient and experimentally attractive route toward implementing hybrid quantum error correction. Subjects: Quantum Physics (quant-ph) Cite as: arXiv:2603.19870 [quant-ph]   (or arXiv:2603.19870v1 [quant-ph] for this version)   https://doi.org/10.48550/arXiv.2603.19870 Focus to learn more Submission history From: Shohei Kiryu [view email] [v1] Fri, 20 Mar 2026 11:36:52 UTC (256 KB) Access Paper: HTML (experimental) view license Current browse context: quant-ph < prev   |   next > new | recent | 2026-03 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?)