Entanglement between an NV Center and Chiral Photons in a Topological SWCNT Plasmonic Microtoroid

Quantum Physics [Submitted on 31 Mar 2026] Entanglement between an NV Center and Chiral Photons in a Topological SWCNT Plasmonic Microtoroid Fang-Yu Hong We present a theoretical proposal for a hybrid solid-state quantum node based on a single nitrogen-vacancy (NV) center coupled to a topological single-walled carbon nanotube (SWCNT) plasmonic microtoroid. The SWCNT ring supports deeply sub-wavelength whispering-gallery-like plasmonic modes that are naturally described within a Tomonaga-Luttinger liquid framework. Owing to the closed-ring topology, the cavity spectrum contains a zero-mode sector that is tunable by an external magnetic flux through an Aharonov-Bohm shift. We show that the strongly confined CNT near field can exhibit chiral spin-momentum locking, enabling the two circularly polarized NV transitions to couple selectively to clockwise and counter-clockwise cavity modes, while the parasitic linearly polarized \pi-transition is strongly suppressed by the pronounced anisotropy of the local Purcell enhancement. Based on a tripod stimulated Raman adiabatic passage (STIRAP) scheme, the system can in principle map the NV spin onto a spin-photon entangled state in a deterministic manner, which is then emitted into a side-coupled tapered optical fiber as a tunable flying qubit. We derive the cavity spectrum, the chiral selection rules, the effective tripod Hamiltonian, and the open-system master equation. Quantitative estimates indicate that, under cryogenic conditions and in the overcoupled regime, high-fidelity spin-photon entanglement and in situ magnetic tuning of the emitted photon frequency are in principle achievable. We also discuss a realistic fabrication route for the CNT resonator and deterministic positioning strategies for a single NV center in the CNT near field. Comments: 9 pages, 3 figures Subjects: Quantum Physics (quant-ph) Cite as: arXiv:2603.29290 [quant-ph]   (or arXiv:2603.29290v1 [quant-ph] for this version)   https://doi.org/10.48550/arXiv.2603.29290 Focus to learn more Submission history From: Fang-Yu Hong [view email] [v1] Tue, 31 Mar 2026 05:50:31 UTC (3,142 KB) Access Paper: 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?)