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arxiv: 2605.04016 · v1 · submitted 2026-05-05 · ✦ hep-th · quant-ph

Recognition: unknown

Entangling gates for the SU(N) anyons

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Pith reviewed 2026-05-07 15:03 UTC · model grok-4.3

classification ✦ hep-th quant-ph
keywords SU(N) anyonstopological quantum computingChern-Simons theoryentangling gatesknot cablingbraiding operationsfusion rules
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The pith

Cabling of knots extends the construction of entangling gates from SU(2) anyons to the SU(N) case.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

This paper examines how to generalize a cabling-based method for two-qubit entangling gates, previously developed for SU(2) Chern-Simons theory, to SU(N) anyons. The SU(2) approach relies on braiding anyon trajectories and cabling knots to produce noise-resistant quantum operations. For SU(N), the higher-rank structure changes the fusion rules and knot invariants, requiring adjustments to the cabling technique and raising fresh implementation issues. A reader would care because successful extension would expand the family of anyons usable for fault-tolerant topological quantum computing beyond the simplest models.

Core claim

The cabling construction developed for SU(2) Chern-Simons theory admits a generalization to SU(N), where the required modifications, the differences between the anyon models, and the new problems that arise in building entangling gates are identified and discussed.

What carries the argument

Cabling of knots, which combines multiple anyon strands to produce effective braiding operations that implement two-qubit entangling gates in the topological model.

If this is right

  • Entangling gates for SU(N) anyons can be constructed by adapting the knot-cabling procedure.
  • Differences in fusion rules and braid representations between SU(2) and SU(N) must be incorporated into gate design.
  • New technical problems appear in ensuring the operations remain protected against local errors.
  • The method opens a route to multi-qubit operations in anyon systems with rank greater than two.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • The extension could support topological quantum computers using qudits with dimension larger than two.
  • It may connect to generalizations of knot polynomials such as the HOMFLY polynomial for SU(N).
  • Small-N cases could be tested by computing explicit braid matrices and checking whether they generate entanglement.
  • Experimental searches for suitable anyons might prioritize models where the cabling remains computationally tractable.

Load-bearing premise

The cabling construction for SU(2) admits a direct and useful extension to SU(N) without fundamental obstructions from representation theory or knot invariants.

What would settle it

An explicit calculation for SU(3) showing that no cabling configuration produces a topologically protected entangling gate whose matrix elements are invariant under continuous deformations of the knot diagram.

Figures

Figures reproduced from arXiv: 2605.04016 by Andrey Morozov, Sergey Mironov.

Figure 1
Figure 1. Figure 1: A graphical description of an R-matrix actually depends on the irreducible representations from the product of two initial representations, and moreover it acts on them by just multiplying them by a corresponding eigenvalue: V1 ⊗ V2 = PQ; Rˆ (V1 ⊗ V2) = PRˆQ = PλQQ; λQ ∼ εQq κQ , κQ = P (i,j)∈Q (i − j), (5) where εQ are the signs of eigenvalues, which depend on whether the representation Q comes from the p… view at source ↗
Figure 2
Figure 2. Figure 2: Braid description of a trefoil knot with three and four strands. The left braid should be closed as a traditional view at source ↗
Figure 3
Figure 3. Figure 3: Plat representation of a link L6a1. On the left the corresponding view at source ↗
Figure 4
Figure 4. Figure 4: A trefoil knot on the left and a 2-cabled trefoil knot on the right. The strand is replaced with two parallel view at source ↗
Figure 5
Figure 5. Figure 5: Cabled R-matrix. The R-matrix in representation [2] can be built from a product of four R-matrices in the fundamental representation on the right. Indices of the matrices on the right indicate which matrix in the four-strand braid should be taken. 5 One-qubit topological operations The idea of a topological quantum computer is based on using the evolution of anyons as a medium for quantum calculations. Due… view at source ↗
Figure 6
Figure 6. Figure 6: In a topological quantum computer, a one-qubit operation corresponds to a 4-strand braid. From the braid view at source ↗
Figure 7
Figure 7. Figure 7: Different entanglements of two qubits. Most of them move the system out of computational space. view at source ↗
Figure 8
Figure 8. Figure 8: Entangling of two qubits with the cables on the left can be interpreted as a braid in higher representations on view at source ↗
Figure 9
Figure 9. Figure 9: Two types of the first Reidemeister move for parallel (on the left) and anti-parallel (on the right) strands. view at source ↗
Figure 10
Figure 10. Figure 10: Notation for an entangling cabled braid [ view at source ↗
Figure 11
Figure 11. Figure 11: Examples of braid for the patterns from the table for co-directional cables. view at source ↗
Figure 12
Figure 12. Figure 12: Examples of braid for the patterns from the table for counter-directional cables. view at source ↗
read the original abstract

The model of a topological quantum computer is a promising one due to its natural resistance to noise and other errors. Operations in such a computer are implemented by braiding the trajectories of anyons. While it is easy to understand how to build one-qubit operations, two-qubit operations are more difficult. In arXiv:2412.20931 we suggested an approach to build such operations for a topological quantum computer based on SU(2) Chern-Simons theory with arbitrary level using cabling of knots. In this paper we discuss how this approach should be generalized to the SU(N) case, what the differences are, and which new problems arise.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

1 major / 1 minor

Summary. The paper discusses generalizing the cabling construction for entangling gates from SU(2) Chern-Simons theory (as in the authors' prior work arXiv:2412.20931) to the SU(N) case. It focuses on identifying differences between the two settings and the new problems that arise, without providing explicit constructions or derivations.

Significance. If the discussion accurately flags genuine obstructions or differences in the SU(N) extension, it could usefully orient future research on higher-rank anyonic gates. However, the absence of concrete analysis or examples means the significance is limited to a high-level outline rather than advancing the field with new results or tools.

major comments (1)
  1. [Abstract] Abstract: the manuscript states an intent to discuss the generalization, differences, and new problems for SU(N) anyons but supplies no derivations, explicit constructions, equations, or illustrative examples. This is load-bearing because the central claim is precisely that discussion, yet the text reduces to a statement of intent without substance.
minor comments (1)
  1. [Introduction] The manuscript assumes familiarity with the cabling method from arXiv:2412.20931 without a brief recap of its key steps or results, which hinders readability for a general audience.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for their review and the opportunity to respond. We address the major comment below, clarifying the scope and intent of the manuscript while agreeing to strengthen its substance.

read point-by-point responses
  1. Referee: [Abstract] Abstract: the manuscript states an intent to discuss the generalization, differences, and new problems for SU(N) anyons but supplies no derivations, explicit constructions, equations, or illustrative examples. This is load-bearing because the central claim is precisely that discussion, yet the text reduces to a statement of intent without substance.

    Authors: We appreciate the referee's observation that the manuscript is concise and high-level. The paper is structured as a short discussion note whose central contribution is precisely to outline the generalization of the cabling construction from our prior SU(2) work, to flag concrete differences (such as the richer fusion rules and higher-dimensional representations in SU(N) Chern-Simons theory), and to identify new technical problems (including greater complexity in evaluating the associated quantum invariants and potential additional obstructions to finding entangling cablings). While the current text keeps technical detail minimal to emphasize these conceptual points, we agree that the discussion would benefit from added substance. In the revised version we will incorporate illustrative examples of the differences in braiding matrices, key equations for the SU(N) cabling procedure, and at least one partial derivation showing how a new problem arises. revision: yes

Circularity Check

0 steps flagged

No significant circularity; discussion paper with no load-bearing derivations

full rationale

The paper is explicitly a discussion piece on generalizing the cabling construction for entangling gates from the authors' prior SU(2) work (arXiv:2412.20931) to SU(N) Chern-Simons theory. It identifies differences and new problems without presenting any new theorem, quantitative prediction, fitted parameter, or derivation chain. No equations or constructions are advanced that reduce by construction to inputs from the cited paper. The self-citation serves only as background reference for the approach being discussed, not as a load-bearing justification for any claim. Per the guidelines, this is a self-contained discussion with no circular steps; the central content does not assert a successful extension or force any result from prior fitted quantities.

Axiom & Free-Parameter Ledger

0 free parameters · 0 axioms · 0 invented entities

Abstract-only review supplies no explicit free parameters, axioms, or invented entities; the ledger is therefore empty.

pith-pipeline@v0.9.0 · 5397 in / 1009 out tokens · 58375 ms · 2026-05-07T15:03:56.331268+00:00 · methodology

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Reference graph

Works this paper leans on

41 extracted references · 32 canonical work pages · 1 internal anchor

  1. [1]

    A. Y. Kitaev, Russian Mathematical Surveys, 52 (1997), 1191

  2. [2]

    Simon and Ady Stern and Das Sarma, Sankar , Date-Added =

    C. Nayak, S. H. Simon, A. Stern, M. Freedman, S. Das Sarma, Rev. Mod. Phys. 80 (2008), 1083, [arXiv:0707.1889 [hep-th]]

  3. [3]

    R. S. Souto, A. Tsintzis, M. Leijnse, J. Danon, Phys. Rev. Research 5, 043182 (2023) [arXiv:2308.14751 [cond- mat]]

  4. [4]

    D. Zou, N. Pan, T. Chen, H. Sun, X. Zhang, Adv. Intell. Syst. 2300354 (2023) [arXiv:2309.04896 [cond-mat]]

  5. [5]

    Winblad, H

    A. Winblad, H. Chen, [arXiv:2309.11607 [cond-mat]]

  6. [6]

    Bonderson, A

    P. Bonderson, A. Kitaev, K. Shtengel, Phys. Rev. Lett. 96, 016803 (2006) [arXiv:cond-mat/0508616]

  7. [7]

    69 De Groote, R

    J. Nakamura, S. Liang, G. C. Gardner, M. J. Manfra, Nat. Phys. 16, 931–936 (2020), doi:10.1038/s41567-020- 1019-1 [arXiv:2006.14115 [cond-mat]]. 15

  8. [8]

    Dom´ ınguez, F

    F. Dom´ ınguez, F. Hassler, G. Platero, [arXiv:1202.0642 [cond-mat]]

  9. [9]

    Kauffman, S

    L. Kauffman, S. Lomonaco, New Journal of Physics,4(2002) 73.1-18; 6 (2004) 134.1-40, [arXiv:quant- ph/0401090]

  10. [10]

    S. H. Simon, Topological Quantum (Oxford, 2023; online edn, Oxford Academic, 14 Dec. 2023)

  11. [11]

    Melnikov, A

    D. Melnikov, A. Mironov, S. Mironov, A. Morozov and A. Morozov, Nucl. Phys. B926(2018), 491-508 [arXiv:1703.00431 [hep-th]]

  12. [12]

    Kolganov and A

    N. Kolganov and A. Morozov, JETP Lett.111(2020) no.9, 519-524 [arXiv:2004.07764 [hep-th]]

  13. [13]

    Kolganov, S

    N. Kolganov, S. Mironov and A. Morozov, Nucl. Phys. B987(2023), 116072 [arXiv:2105.03980 [hep-th]]

  14. [14]

    Morozov, Probl.Info.Transm

    A. Morozov, Probl.Info.Transm. 60 (2024) 28-34 [arXiv:2403.07847 [hep-th]]

  15. [15]

    Mironov and A

    S. Mironov and A. Morozov, Phys. Rev. D 110, 126020, 2024 [arXiv:2404.12222 [hep-th]]

  16. [16]

    J. Long, Z. Liu, Y. Li, J. Zhong and L. Meng, [arXiv:2602.15324 [quant-ph]]

  17. [17]

    J. Long, Y. Li, J. Zhong and L. Meng, Phys. Lett. A565, 131142 (2026) [arXiv:2505.01774 [quant-ph]]

  18. [18]

    Levaillant, B

    C. Levaillant, B. Bauer, M. Freedman, Z. Wang and P. Bonderson, Phys. Rev. A92, no.1, 012301 (2015) [arXiv:1504.02098 [quant-ph]]

  19. [19]

    A. L. Kaufmann and S. X. Cui, Quant. Inf. Proc.24, no.1, 14 (2025) [arXiv:2312.16747 [quant-ph]]

  20. [20]

    Mironov, A

    S. Mironov, A. Morozov, Eur.Phys.J.C85(2025) 7, 799 [arXiv:2412.20931 [quant-ph]]

  21. [21]

    Cabling procedure for the colored HOMFLY polynomials

    A. Anokhina and An. Morozov, Teor. Mat. Fiz.178(2014), 3-68 [arXiv:1307.2216 [hep-th]]

  22. [22]

    Witten, Commun

    E. Witten, Commun. Math. Phys. 121, 351 (1989)

  23. [23]

    Turaev, The Yang-Baxter equation and invariants of links, Invent.Math

    V.G. Turaev, The Yang-Baxter equation and invariants of links, Invent.Math. 92 (1988) 527-553

  24. [24]

    Reshetikhin, and V.G

    N.Yu. Reshetikhin, and V.G. Turaev, Commun.Math.Phys. 127 (1990) 1-26

  25. [25]

    Reshetikhin, V.G

    N. Reshetikhin, V.G. Turaev, Invent.Math. 103 (1991) 547-597

  26. [26]

    Character expansion for HOMFLY polynomials. II. Fundamental representation. Up to five strands in braid

    A. Mironov, A. Morozov, An. Morozov, CJHEP 03 (2012) 034, [arXiv:1112.2654 [hep-th]]

  27. [27]

    Character expansion for HOMFLY polynomials. III. All 3-Strand braids in the first symmetric representation

    H. Itoyama, A. Mironov, A. Morozov, An. Morozov, International Journal of Modern Physics A 27 (2012) 1250099, [arXiv:1204.4785 [hep-th]]

  28. [28]

    Tabulating knot polynomials for arborescent knots

    A. Mironov, A. Morozov, A. Morozov, P. Ramadevi, V. K. Singh and A. Sleptsov, J. Phys. A50(2017) no.8, 085201 [arXiv:1601.04199 [hep-th]]

  29. [29]

    Mironov, A

    A. Mironov, A. Morozov, A. Morozov, P. Ramadevi and V. K. Singh, JHEP07(2015), 109 [arXiv:1504.00371 [hep-th]]

  30. [30]

    Nawata, P

    S. Nawata, P. Ramadevi and Zodinmawia, Lett. Math. Phys. 103 (2013), 1389-1398, [arXiv:1302.5143 [hep-th]]

  31. [31]

    Mironov, A

    A. Mironov, A. Morozov, A. Sleptsov, JHEP07(2015) 069, [arXiv:1412.8432 [hep-th]]

  32. [32]

    and Schm¨ udgen, K

    Klimyk, A. and Schm¨ udgen, K. Quantum groups and their representations. Springer Science & Business Media (2012)

  33. [33]

    Eigenvalue hypothesis for multi-strand braids

    Saswati Dhara, A. Mironov, A. Morozov, An. Morozov, P. Ramadevi, Vivek Kumar Singh, A. Sleptsov, Phys. Rev. D 97, 126015 (2018), [arXiv:1711.10952 [hep-th]]

  34. [34]

    Colored knot polynomials. HOMFLY in representation [2,1]

    A. Mironov, A. Morozov, An. Morozov, A. Sleptsov, Int. J. Mod. Phys. A 30 (2015) 1550169, [arXiv:1508.02870 [hep-th]]

  35. [35]

    Mironov, A

    A. Mironov, A. Morozov and A. Sleptsov, JETP Lett. 106 (2017) no.10, 630-636, [arXiv:1709.02290 [hep-th]]

  36. [36]

    Kauffman, The Interface of Knots and Physics, AMS, 1996

    Louis H. Kauffman, The Interface of Knots and Physics, AMS, 1996

  37. [37]

    V.Prasolov, A.Sosinski, Amer. Math. Soc. Publ., Providence, R.I., 1996 16

  38. [38]

    P.Borhade, P.Ramadevi, T.Sarkar, Nucl.Phys.B678 (2004) 656-681, [arXiv:hep-th/0306283]

  39. [39]

    E. O. Kiktenko, A. S. Nikolaeva and A. K. Fedorov, Rev. Mod. Phys.97(2025) no.2, 021003 [arXiv:2311.12003 [quant-ph]]

  40. [40]

    Universal Racah matrices and adjoint knot polynomials. I. Arborescent knots

    A. Mironov and A. Morozov, Physics Letters B755 (2016) 47-57 [arXiv:1511.09077 [hep-th]]

  41. [41]

    Alekseev, An

    V. Alekseev, An. Morozov and A. Sleptsov, Nucl. Phys. B 960 (2020), 115164, [arXiv:1912.13325 [hep-th]] 17