Pith. sign in

REVIEW 4 major objections 5 minor 87 references

Approximate Dynamical Quantum Error-Correcting Codes

T0 review · 4 major / 5 minor · reviewed 2026-08-07 · deepseek-v4-flash

Pith's one-line read Optimal approximate dynamical codes are unique and stable under noise

desk verdict A genuinely new combination of approximate and dynamical QEC with an honest numerical study, but Theorem 1's uniqueness claim is only proved for each SDP subproblem, not for the nonconvex see-saw problem it is stated for. read the letter →

arxiv 2502.09177 v2 pith:OTFRI5CJ submitted 2025-02-13 quant-ph

classification quant-ph MSC 81P7081P6890C22 PACS 03.67.Pp03.67.-a
keywords approximatequantumerrorcorrectiondynamicalcodesstrategiccodeframeworksemidefiniteprogrammingamplitudedampingnoisePetzrecoverymapentanglementfidelitycombs
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

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

The reading

Quantum error correction usually either protects against all noise types at high resource cost, or is tailored to a specific noise model but remains static. This paper claims the tailored approach can be extended to dynamical codes, where the codespace evolves through time-dependent check operations. Using the strategic code framework, it formulates code design as a semidefinite program and proves that the optimal encoding channel, check instrument, and decoding channel are unique and robust under small perturbations. It also introduces a temporal Petz recovery map that coincides with the perfect recovery map whenever the code exactly corrects the noise. Explicit 2- and 3-qubit protocols for amplitude-damping noise are constructed and reported to outperform several standard small static codes.

What carries the argument

The central object is the strategic code $Q = \sum_m C^{(0)} \otimes C^{(1)}_m \otimes D_m$, a Choi-operator description of an entire error-correction protocol as one positive operator, with an interrogator $T = \sum_m |C_m\rangle\rangle\langle\langle C_m|$ representing the time-ordered check operations. The paper maximizes entanglement fidelity $\mathrm{Tr}(E * Q |\rho\rangle\rangle\langle\langle \rho|)$ over valid Choi operators subject to positivity and trace constraints. The proof machinery is semidefinite programming: the see-saw algorithm alternates optimizing the decoder, the check instrument, and the encoder, and Theorem 1 uses dual nondegeneracy (no nonzero symmetric $M$ solves $M Y^* = 0$ and $\Xi(M) = 0$) together with a robustness bound to conclude uniqueness and $O(\epsilon)$ stability. The temporal Petz recovery map is the natural multi-time generalization of the static Petz map, with Kraus operators built from the interrogator, the initial codespace projector, and the noise operators.

What would settle it

Run the see-saw algorithm on a 2-qubit amplitude-damping code at damping strength $\gamma = 0.2$ from many random feasible starting points and compute the Frobenius distance between the returned Choi operators; a nonzero separation, or a direct numerical solution of the homogeneous system $M Y^* = 0$ with $\mathrm{Tr}[M(I \otimes Y^*)] = 0$ at the returned optimum, would show the optimum is not unique and Theorem 1 fails.

Watch

Extended reading notes

Core claim

The paper's central claim is that approximate dynamical quantum error-correcting codes can be found by solving one optimization program, and that the solution is well posed: Theorem 1 states that the optimal Choi operators $C^{(0)*}$, $C^{(1)*}_m$, and $D^*_m$ for encoding, check instrument, and decoding are unique and robust, with Frobenius-norm deviations of order $O(\epsilon)$ for any $\epsilon$-feasible alternatives. The argument proceeds through a see-saw SDP algorithm, using dual nondegeneracy to force a unique primal optimum and a known robustness bound to control nearby feasible solutions. The paper further claims a temporal Petz recovery map whose Kraus operators match the perfect recovery map whenever exact correction is possible, and an entanglement-fidelity guarantee $F \ge 1 - 2\sqrt{\epsilon}$ when the entropy-based correction deficit is below $\epsilon$. For amplitude-damping noise, the constructed 2-, 3-, and 4-qubit dynamical codes are reported to beat several standard approximate static codes in fidelity.

Load-bearing premise

The proof of uniqueness and robustness depends on the claim that the optimal dual solution $Y^*$ of the SDP is dual nondegenerate, and that claim is asserted rather than fully derived; if a nontrivial $M$ satisfying the homogeneous system exists, the uniqueness and $O(\epsilon)$ robustness conclusions do not follow.

Editorial extensions

If this is right

  • If Theorem 1 holds, the see-saw algorithm's output is not an arbitrary local optimum: any $\epsilon$-feasible alternative is within $O(\epsilon)$, so the reported protocols are representative of the true optimum.
  • Approximate dynamical codes can be tailored to dominant noise such as amplitude damping with only two or three physical qubits, making time-dependent checks viable for near-term devices.
  • The temporal Petz recovery map provides a canonical decoder for dynamical codes, extending optimal-recovery results from static to multi-round error correction.
  • The fidelity bound $F \ge 1 - 2\sqrt{\epsilon}$ gives a simple information-theoretic criterion: if the entropy deficit is small, near-perfect recovery is guaranteed.
  • Static approximate QEC is recovered as a special case, unifying static and dynamical approximate code design in one optimization framework.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • A natural test the paper leaves implicit: run the see-saw algorithm from many random feasible starting points and check that the returned Choi operators agree to numerical precision, which would corroborate the claimed uniqueness in practice.
  • The same SDP strategy could be extended to non-Markovian noise with memory, since the strategic code formalism already accommodates multi-time correlations, though the uniqueness proof would need to be rechecked for the larger feasible set.
  • The temporal Petz map may serve as a benchmark for other approximate dynamical decoders, analogous to how the static Petz map benchmarks recovery in ordinary approximate QEC.
Share X Bluesky LinkedIn Reddit HN

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

4 major / 5 minor

Summary. The paper introduces approximate dynamical quantum error-correcting codes by applying the strategic code framework of Ref. [55], and proposes an SDP-based see-saw optimization, Algorithm 1/3, to maximize the entanglement fidelity with respect to a given noise model. The central theoretical claims are Theorem 1 (the optimal encoding channel, check instrument, and decoding channel obtained from program (3) are unique and robust), a temporal Petz recovery map (Definition 1 and Theorem 3), and an information-theoretic fidelity bound for approximate correction (Theorem 5). The authors demonstrate the method numerically on two- and three-round amplitude-damping noise models, provide explicit 2- and 3-qubit protocols, and supply code in a public GitHub repository. The main gap is in the proof of Theorem 1: the proof in Appendix C establishes at best uniqueness and robustness of the individual linear SDP subproblems of the see-saw, and relies on an unproved dual-nondegeneracy assertion in Lemma 3; moreover, the global trilinear program (3) is nonconvex and the paper itself concedes in Section IV that the algorithm may report a local maximum. The other two main results, the temporal Petz recovery map and the fidelity bound, are more self-contained and appear sound, up to presentation issues.

Significance. If the uniqueness and robustness claim can be proved in a suitably scoped form, the paper would provide a useful practical tool for noise-tailored dynamical QEC: the SDP-based see-saw with explicit 2- and 3-qubit amplitude-damping codes, the temporal Petz recovery map, and the fidelity bound in Theorem 5 are concrete contributions, and the availability of reproducible code is a clear strength. The comparison with static codes in Figures 2, 3, 6, and 7 is informative even though the see-saw output may be only a local optimum. However, the headline mathematical claim of the abstract and Theorem 1 currently overstates what is proven, and the dual-nondegeneracy step is load-bearing. The paper's value would be substantially improved by either proving nondegeneracy for the relevant instances, or explicitly restricting the uniqueness/robustness statement to the linear SDP subproblems or to certified stationary points of the see-saw.

major comments (4)
  1. [Section III, Theorem 1, and Appendix C] The theorem as stated concerns program (3), which is trilinear in C^(0), C^(1)_m, and D_m and is therefore nonconvex; the see-saw Algorithm 1/3 is not guaranteed to find a global optimum. The proof in Appendix C only treats the three linear SDP subproblems at lines 6, 8, and 10 of Algorithm 3, and no argument shows that a fixed point of the see-saw is the global optimizer of program (3) or that different initializations cannot yield different fixed points. The paper itself states in Section IV that the program "is reporting a local maxima." Thus Theorem 1's conclusion that the Choi operators obtained by solving program (3) are unique and robust does not follow from the supplied proof; at most, uniqueness/robustness of each linear subproblem would follow if the nondegeneracy issue below is resolved.
  2. [Appendix C, Lemma 3 (and Lemmas 5-6)] Dual nondegeneracy is asserted rather than derived. Definition 2 requires the homogeneous system M Z* = 0 and Ξ(M) = 0 to admit only the trivial solution, where Z* is the dual slack. Lemma 3 instead considers "M Y* = 0" and "Tr[M(I_L' ⊗ Y*)] = 0", then asserts that Y* has a trivial null space and spans the operator space determined by (C0C1)_m. These claims are not proved; the full-rank assertion is nontrivial and may fail for the specific SDPs used in the numerics, and the orthogonality condition used in the lemma is not evidently equivalent to the affine constraint Ξ(M) = 0 in Definition 2. Since Lemma 3 is the sole basis for invoking Fact 6 to obtain uniqueness, the proof chain from Lemma 3 to Lemma 4 to Theorem 1 is incomplete. Lemmas 5 and 6 make the same nondegeneracy assertion without proof and inherit the same gap.
  3. [Theorem 1 and Lemma 4] The robustness statement is not formulated with the correct quantifier. Theorem 1 says that for any feasible ~C^(0), ~C^(1)_m, and ~D_m the Frobenius deviation is O(ε), but ε is not defined in the theorem. Lemma 4 invokes Fact 6, which applies only to primal feasible points satisfying p* - ε ≤ Tr(CX), i.e., ε-optimal feasible points. Feasible points that are far from optimality need not be close to a unique optimum. The theorem should be restated for ε-optimal feasible solutions, with ε made explicit, or the use of O(ε) in the abstract should be corrected accordingly.
  4. [Appendix H, proof of Theorem 3] The proof that the temporal Petz recovery map coincides with the perfect recovery map contains a step whose algebra needs verification. In Eq. (H5), after summing over e and e′, the displayed expression is proportional to Σ_e d^3_{e,m} Π_{Q0}; it is not clear why the third power of d_{e,m} appears rather than a second power or a product of different d factors. The polar-decomposition formalism in Eqs. (H6)-(H9) is compact, and the equality of the Petz Kraus operators with the perfect-recovery Kraus operators should be checked line by line. If the factor is simply a typographical error, it should be corrected; otherwise the proof needs a revised derivation.
minor comments (5)
  1. [Section IV] The phrase "m = 1 in program (3)" is ambiguous: program (3) involves a sum over outcome branches m, and it should be stated whether only one outcome branch is considered and how the trace-preserving normalization Σ_m Tr_{A1}(C^(1)_m) = I_{A0} is handled in that case.
  2. [Throughout] The notation "J5, 1K" and "J3, 1K" should be replaced by the standard quantum code notation [[5,1]] and [[3,1]], since the current notation is nonstandard and appears to be an artifact.
  3. [Eq. (3) and surrounding text] The tensor-product order in program (3) is written as Q = Σ_m D_m ⊗ C^(1)_m ⊗ C^(0), whereas Eq. (1) writes Q = Σ_m C^(0) ⊗ C^(1)_m ⊗ D_m; the tensor-factor labels should be fixed so that the Choi spaces are unambiguous.
  4. [Appendix C, Lemma 2] The proof of Lemma 2 contains a garbled fragment "/Leftr⮯g➸tl⮯ne⇒" that interrupts a displayed equation; the derivation should be cleaned up typographically.
  5. [Appendix I and Theorem 5] The proof of Theorem 5 invokes a specific decoding channel D_m described only by reference to Eq. (29) of Ref. [55]; the proof should either define that channel or state explicitly that it adopts the construction from Ref. [55], so that the argument is self-contained.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity; the derivation chain is supported by external SDP and strategic-code theorems, not by assuming the conclusion.

full rationale

This paper does not exhibit circular reasoning. The central new claim, Theorem 1, is proved in Appendix C from two ingredients: dual nondegeneracy of the SDP subproblems and Fact 6, a distance-to-optimal-set bound for SDPs from Ref. [84]. Fact 6 is a general semidefinite-programming theorem (Bharti et al., PRL 2019) whose statement does not involve approximate dynamical codes; invoking it is legitimate external support, even though one author is shared. The strategic-code facts (Fact 2 and Fact 4) are likewise prior theorems from Ref. [55] with proofs; the paper uses them as lemmas rather than assuming the desired uniqueness or fidelity bound. The temporal Petz recovery map (Definition 1) is an explicit construction; Theorem 3 derives its equality to the perfect recovery map via polar decomposition and the Knill-Laflamme-type condition, so the equality is not assumed by definition. The numerical sections benchmark optimized encoders against existing static codes; no fitted parameter is relabeled as a prediction. The see-saw caveat in Section IV ('the program is reporting a local maxima') is an admitted limitation on global optimality but does not make any local claim circular. The proof of dual nondegeneracy in Lemma 3 is asserted rather than fully derived; that is a correctness gap, not circularity, and does not change this verdict.

Assumptions & free parameters 1 free parameters · 7 assumptions · 0 invented entities

The paper introduces no new physical entities. Its central theoretical claims rest on the strategic code formalism, the chosen amplitude-damping noise ensembles, a hand-chosen split of damping over rounds, and an unproven nondegeneracy assertion in the proof of Theorem 1.

free parameters (1)
  • Two-round amplitude-damping split = gamma0 = gamma/2, gamma1 = gamma/(2-gamma)
    The two-round noise model in Appendix E distributes the total damping strength gamma between rounds. The split is chosen by hand so that the composed channel has damping strength gamma; it is not learned from data and is not a target of the derivation.
assumptions (7)
  • domain assumption Quantum combs and strategic code representation of dynamical codes and noise as positive semidefinite operators, with bilinear action E*Q
    Section III and Appendices B and J use this representation from Refs. [55,62-66] to define the optimization program (3).
  • domain assumption Temporal self-similarity of amplitude-damping noise
    Section IV and Appendix E write two-round amplitude damping with Kraus operators E(l)_{0,*} and E(l)_{1,*} and total strength gamma = gamma0 + gamma1 - gamma0*gamma1, following Ref. [67].
  • domain assumption Local and weight-k noise ensembles for k of n qubits
    Equations (4) and (E3) define the noise ensembles used in all numerical comparisons; the codes are tailored to these ensembles.
  • ad hoc to paper Dual nondegeneracy of the optimal dual solutions in Lemmas 3, 5, and 6
    The proof of Theorem 1 rests on this property; Lemma 3 gives an incomplete argument, and the paper does not prove it for the SDPs in lines 8 and 10 of Algorithm 3 beyond analogy.
  • standard math SDP robustness bound from Fact 6 of Ref. [84] with singularity degree zero
    Used in Appendix C to convert uniqueness into O(epsilon) robustness; Ref. [84] is co-authored by a present author, but it is a general SDP statement.
  • domain assumption Strategic-code correctability condition (Fact 2 from Ref. [55])
    Theorem 3 uses this as the dynamical generalization of the Knill-Laflamme condition to construct the perfect recovery map.
  • standard math Fidelity-relative entropy inequality F(rho,sigma) >= 1 - sqrt(S(rho||sigma))
    Appendix I2 uses this inequality from Ref. [15] to derive the square-root bound in Theorem 5.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Approximate Dynamical Quantum Error-Correcting Codes." pith.science (2026). https://pith.science/paper/OTFRI5CJ

@misc{pith2026250209177,
  author       = {Pith},
  title        = {Pith review of: Approximate Dynamical Quantum Error-Correcting Codes},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/OTFRI5CJ}},
  note         = {Machine review of arXiv:2502.09177}
}
read the original abstract

Quantum error correction plays a critical role in enabling fault-tolerant quantum computing by protecting fragile quantum information from noise. While general-purpose quantum error correction codes are designed to address a wide range of noise types, they often require substantial resources, making them impractical for near-term quantum devices. Approximate quantum error correction provides an alternative by tailoring codes to specific noise environments, reducing resource demands while still maintaining noise-robustness. Dynamical codes, including Floquet codes, introduce a dynamic approach to quantum error correction, employing time-dependent operations to stabilize logical qubits. In this work, we combine the flexibility of dynamical codes with the versatility of approximate quantum error correction to offer a promising avenue for addressing dominant noise in quantum systems. We construct several approximate dynamical codes using the recently developed strategic code framework. As a special case, we recover the approximate static codes widely studied in the existing literature. By analyzing these approximate dynamical codes through semidefinite programming, we establish the uniqueness and robustness of the optimal encoding, decoding, and check measurements. We also develop a temporal Petz recovery map suited to approximate dynamical codes.

Figures

Figures reproduced from arXiv: 2502.09177 by the authors.

Figure 1
Figure 1. We note that a static code in this framework can be simply captured by removing the interrogator T, leaving us with a strategic code Q with encoder C (0) and decoder D (as described in Appendix A). For details on the strategic code and how the objects are represented formally, see Appendix B. III. APPROXIMATE STRATEGIC CODE OPTIMIZATION By using the quantum combs formalism [62–66], we can represent both noise E and … view at source ↗
Figure 2
Figure 2. FIG. 2. The entanglement fidelity [PITH_FULL_IMAGE:figures/full_fig_p004_2.png] view at source ↗
Figure 3
Figure 3. FIG. 3. The entanglement fidelity [PITH_FULL_IMAGE:figures/full_fig_p005_3.png] view at source ↗
Figures from the paper (5 more)
Figure 4
Figure 4. Figure 4: FIG. 4. Static QECC illustration. A static code is defined [PITH_FULL_IMAGE:figures/full_fig_p009_4.png]
Figure 5
Figure 5. Figure 5: FIG. 5. damping strength vs Entanglement Fidelity plot using Algorithm [PITH_FULL_IMAGE:figures/full_fig_p011_5.png]
Figure 6
Figure 6. Figure 6: FIG. 6. The entanglement fidelity [PITH_FULL_IMAGE:figures/full_fig_p016_6.png]
Figure 7
Figure 7. Figure 7: FIG. 7. The entanglement fidelity [PITH_FULL_IMAGE:figures/full_fig_p016_7.png]
Figure 8
Figure 8. Figure 8: FIG. 8. Transmission of one-half of maximally entangled state [PITH_FULL_IMAGE:figures/full_fig_p018_8.png]

Discussion (0). Continue with ORCID to comment.

Reference graph

Works this paper leans on

87 extracted references · 58 canonical work pages

  1. [55]

    Tanggara, M

    A. Tanggara, M. Gu, and K. Bharti, Strategic code: A unified spatio-temporal framework for quan- tum error-correction, arXiv preprint arXiv:2405.17567 10.48550/arXiv.2405.17567 (2024)

  2. [1]

    P. W. Shor, Polynomial-time algorithms for prime factor- ization and discrete logarithms on a quantum computer, SIAM review41, 303 (1999)

  3. [2]

    Arora and B

    S. Arora and B. Barak, Computational complexity: a modern approach (Cambridge University Press, 2009)

  4. [3]

    M. A. Nielsen and I. L. Chuang, Quantum computa- tion and quantum information: 10th Anniversary Edi- tion (Cambridge University Press, 2010)

  5. [4]

    I. D. Kivlichan, C. Gidney, D. W. Berry, N. Wiebe, J. McClean, W. Sun, Z. Jiang, N. Rubin, A. Fowler, A. Aspuru-Guzik, et al. , Improved fault-tolerant quan- tum simulation of condensed-phase correlated electrons via trotterization, Quantum4, 296 (2020)

  6. [5]

    E. T. Campbell, Early fault-tolerant simulations of the hubbard model, Quantum Science and Technology 7, 015007 (2021)

  7. [6]

    P. W. Shor, Scheme for reducing decoherence in quantum computer memory, Physical review A52, R2493 (1995)

  8. [7]

    Gottesman, Stabilizer codes and quantum error cor- rection (California Institute of Technology, 1997)

    D. Gottesman, Stabilizer codes and quantum error cor- rection (California Institute of Technology, 1997)

Show all 87 references
  1. [8]

    Dennis, A

    E. Dennis, A. Kitaev, A. Landahl, and J. Preskill, Topological quantum memory, Journal of Mathematical Physics 43, 4452 (2002)

  2. [9]

    A. Y. Kitaev, Fault-tolerant quantum computation by anyons, Annals of physics303, 2 (2003)

  3. [10]

    D. A. Lidar and T. A. Brun,Quantum error correction (Cambridge university press, 2013)

  4. [11]

    B. M. Terhal, Quantum error correction for quantum memories, Reviews of Modern Physics87, 307 (2015)

  5. [12]

    Wootters, Mixed-state entanglement and quantum error correction, Physical Review A54, 3824 (1996)

    C.H.Bennett, D.P.DiVincenzo, J.A.Smolin,andW.K. Wootters, Mixed-state entanglement and quantum error correction, Physical Review A54, 3824 (1996)

  6. [13]

    D. W. Leung, M. A. Nielsen, I. L. Chuang, and Y. Ya- mamoto, Approximate quantum error correction can lead to better codes, Physical Review A56, 2567 (1997)

  7. [14]

    A. S. Fletcher, P. W. Shor, and M. Z. Win, Optimum quantum error recovery using semidefinite programming, Physical Review A75, 012338 (2007)

  8. [15]

    Schumacher and M

    B. Schumacher and M. D. Westmoreland, Approximate quantum error correction, Quantum Information Pro- 8 cessing 1, 5 (2002)

  9. [16]

    H. K. Ng and P. Mandayam, Simple approach to ap- proximate quantum error correction based on the trans- pose channel, Physical Review A—Atomic, Molecular, and Optical Physics81, 062342 (2010)

  10. [17]

    Faist, S

    P. Faist, S. Nezami, V. V. Albert, G. Salton, F. Pastawski, P. Hayden, and J. Preskill, Continuous symmetries and approximate quantum error correction, Physical Review X10, 041018 (2020)

  11. [18]

    Hayden and G

    P. Hayden and G. Penington, Approximate quantum er- ror correction revisited: introducing the alpha-bit, Com- munications in Mathematical Physics374, 369 (2020)

  12. [19]

    Zhou and L

    S. Zhou and L. Jiang, Optimal approximate quantum error correction for quantum metrology, Physical Review Research 2, 013235 (2020)

  13. [20]

    Bény and O

    C. Bény and O. Oreshkov, General conditions for approx- imate quantum error correction and near-optimal recov- ery channels, Physical review letters104, 120501 (2010)

  14. [21]

    Cafaro and P

    C. Cafaro and P. van Loock, Approximate quantum er- ror correction for generalized amplitude-damping errors, Physical Review A89, 022316 (2014)

  15. [22]

    Crépeau, D

    C. Crépeau, D. Gottesman, and A. Smith, Approxi- mate quantum error-correcting codes and secret shar- ing schemes, inAnnual International Conference on the Theory and Applications of Cryptographic Techniques (Springer, 2005) pp. 285–301

  16. [23]

    J. Yi, W. Ye, D. Gottesman, and Z.-W. Liu, Complex- ity and order in approximate quantum error-correcting codes, Nature Physics20, 1798 (2024)

  17. [24]

    Klesse, Approximate quantum error correction, ran- dom codes, and quantum channel capacity, Physical Re- view A75, 062315 (2007)

    R. Klesse, Approximate quantum error correction, ran- dom codes, and quantum channel capacity, Physical Re- view A75, 062315 (2007)

  18. [25]

    S. Sang, T. H. Hsieh, and Y. Zou, Approximate quan- tum error correcting codes from conformal field theory, Physical Review Letters133, 210601 (2024)

  19. [26]

    Ben-Aroya and A

    A. Ben-Aroya and A. Ta-Shma, Approximate quantum error correction for correlated noise, IEEE transactions on information theory57, 3982 (2011)

  20. [27]

    J. M. Renes, Uncertainty relations and approximate quantum error correction, Physical Review A94, 032314 (2016)

  21. [28]

    Zhao and D

    Y. Zhao and D. E. Liu, Extracting error thresholds through the framework of approximate quantum error correctioncondition, PhysicalReview Research6,043258 (2024)

  22. [29]

    Buscemi, Entanglement measures and approximate quantum error correction, Physical Review A77, 012309 (2008)

    F. Buscemi, Entanglement measures and approximate quantum error correction, Physical Review A77, 012309 (2008)

  23. [30]

    Mandayam and H

    P. Mandayam and H. K. Ng, Towards a unified frame- work for approximate quantum error correction, Physical Review A86, 012335 (2012)

  24. [31]

    Jayashankar and P

    A. Jayashankar and P. Mandayam, Pretty good state transfer via adaptive quantum error correction, Physical Review A98, 052309 (2018)

  25. [32]

    Biswas, S

    D. Biswas, S. Utagi, and P. Mandayam, Noise-adapted quantum error correction for non-markovian noise, arXiv preprint arXiv:2411.09637 10.48550/arXiv.2411.09637 (2024)

  26. [33]

    Dutta, D

    S. Dutta, D. Biswas, and P. Mandayam, Noise-adapted qudit codes for amplitude-damping noise, arXiv preprint arXiv:2406.02444 10.48550/arXiv.2406.02444 (2024)

  27. [34]

    M. B. Hastings and J. Haah, Dynamically generated log- ical qubits, Quantum5, 564 (2021)

  28. [35]

    Davydova, N

    M. Davydova, N. Tantivasadakarn, and S. Balasubra- manian, Floquet codes without parent subsystem codes, PRX Quantum4, 020341 (2023)

  29. [36]

    Haah and M

    J. Haah and M. B. Hastings, Boundaries for the honey- comb code, Quantum6, 693 (2022)

  30. [37]

    Gidney, M

    C. Gidney, M. Newman, A. Fowler, and M. Broughton, A fault-tolerant honeycomb memory, Quantum 5, 605 (2021)

  31. [38]

    Gidney, M

    C. Gidney, M. Newman, and M. McEwen, Benchmarking the planar honeycomb code, Quantum6, 813 (2022)

  32. [39]

    Hilaire, T

    P. Hilaire, T. Dessertaine, B. Bourdoncle, A. Denys, G. de Gliniasty, G. Valentí-Rojas, and S. Mansfield, Enhanced fault-tolerance in photonic quantum com- puting: Floquet code outperforms surface code in tailored architecture, arXiv preprint arXiv:2410.07065 10.48550/arXiv.24...

  33. [40]

    Vuillot, Planar floquet codes, arXiv preprint arXiv:2110.05348 10.48550/arXiv.2110.05348 (2021)

    C. Vuillot, Planar floquet codes, arXiv preprint arXiv:2110.05348 10.48550/arXiv.2110.05348 (2021)

  34. [41]

    Paetznick, C

    A. Paetznick, C. Knapp, N. Delfosse, B. Bauer, J. Haah, M.B.Hastings,andM.P.daSilva,Performanceofplanar floquet codes with majorana-based qubits, PRX Quan- tum 4, 010310 (2023)

  35. [42]

    Fu and D

    X. Fu and D. Gottesman, Error correction in dynamical codes, arXiv preprint arXiv:2403.04163 10.48550/arXiv.2403.04163 (2024)

  36. [43]

    Fahimniya, S

    A. Fahimniya, S. Mathew, H. Dehghani, K. Bharti, A. Kollar, A. Gorshkov, and M. Gullans, Hyperbolic floquet quantum error correcting codes, in APS March Meeting Abstracts, Vol. 2023 (2023) pp. N64–009

  37. [44]

    Higgott and N

    O. Higgott and N. P. Breuckmann, Constructions and performance of hyperbolic and semi-hyperbolic floquet codes, PRX Quantum5, 040327 (2024)

  38. [45]

    Tanggara, M

    A. Tanggara, M. Gu, and K. Bharti, Simple construc- tion of qudit floquet codes on a family of lattices, arXiv preprint arXiv:2410.02022 10.48550/arXiv.2410.02022 (2024)

  39. [46]

    M. S. Kesselring, J. C. M. de la Fuente, F. Thomsen, J. Eisert, S. D. Bartlett, and B. J. Brown, Anyon con- densation and the color code, PRX Quantum5, 010342 (2024)

  40. [47]

    Bombin, D

    H. Bombin, D. Litinski, N. Nickerson, F. Pastawski, and S. Roberts, Unifying flavors of fault tolerance with the ZX calculus, Quantum8, 1379 (2024)

  41. [48]

    Davydova, N

    M. Davydova, N. Tantivasadakarn, S. Balasubramanian, and D. Aasen, Quantum computation from dynamic au- tomorphism codes, Quantum8, 1448 (2024)

  42. [49]

    Aasen, J

    D. Aasen, J. Haah, Z. Li, and R. S. K. Mong, Measure- ment quantum cellular automata and anomalies in flo- quet codes (2023)

  43. [50]

    A. Dua, N. Tantivasadakarn, J. Sullivan, and T. D. El- lison, Engineering 3D floquet codes by rewinding, PRX Quantum 5, 020305 (2024)

  44. [51]

    Zhang, D

    Z. Zhang, D. Aasen, and S. Vijay, X-cube floquet code: A dynamical quantum error correcting code with a subex- tensive number of logical qubits, Physical Review B108, 205116 (2023)

  45. [52]

    Berthusen and D

    N. Berthusen and D. Gottesman, Partial Syndrome Mea- surement for Hypergraph Product Codes, Quantum 8, 1345 (2024)

  46. [53]

    T. D. Ellison, J. Sullivan, and A. Dua, Floquet codes with a twist, arXiv preprint arXiv:2306.08027 10.48550/arXiv.2306.08027 (2023)

  47. [54]

    Sullivan, R

    J. Sullivan, R. Wen, and A. C. Potter, Floquet codes and phases in twist-defect networks, Physical Review B108, 9 195134 (2023)

  48. [56]

    Barnum and E

    H. Barnum and E. Knill, Reversing quantum dynamics with near-optimal quantum and classical fidelity, Journal of Mathematical Physics43, 2097 (2002)

  49. [57]

    A.PrakashandB.HebbeMadhusudhana,Characterizing non-markovian and coherent errors in quantum simula- tion, Physical Review Research6, 043127 (2024)

  50. [58]

    Hakoshima, Y

    H. Hakoshima, Y. Matsuzaki, and S. Endo, Relationship between costs for quantum error mitigation and non- markovian measures, Physical Review A 103, 012611 (2021)

  51. [59]

    Oreshkov and T

    O. Oreshkov and T. A. Brun, Continuous quantum er- ror correction for non-markovian decoherence, Physical Review A—Atomic, Molecular, and Optical Physics76, 022318 (2007)

  52. [60]

    F. A. Pollock, C. Rodríguez-Rosario, T. Frauenheim, M. Paternostro, and K. Modi, Non-markovian quantum processes: Complete framework and efficient characteri- zation, Physical Review A97, 012127 (2018)

  53. [61]

    F. A. Pollock, C. Rodríguez-Rosario, T. Frauenheim, M. Paternostro, and K. Modi, Operational markov condi- tion for quantum processes, Physical review letters120, 040405 (2018)

  54. [62]

    Milz and K

    S. Milz and K. Modi, Quantum stochastic processes and quantum non-markovian phenomena, PRX Quantum2, 030201 (2021)

  55. [63]

    Chiribella, G

    G. Chiribella, G. M. D’Ariano, and P. Perinotti, Theoret- ical framework for quantum networks, Physical Review A 80, 022339 (2009)

  56. [64]

    Gutoski and J

    G. Gutoski and J. Watrous, Toward a general theory of quantum games, in Proceedings of the thirty-ninth an- nual ACM symposium on Theory of computing (2007) pp. 565–574

  57. [65]

    Chiribella, G

    G. Chiribella, G. M. D’Ariano, and P. Perinotti, Quan- tum circuit architecture, Physical review letters 101, 060401 (2008)

  58. [66]

    Oreshkov, F

    O. Oreshkov, F. Costa, and Č. Brukner, Quantum corre- lations with no causal order, Nature communications3, 1092 (2012)

  59. [67]

    Utagi, R

    S. Utagi, R. Srikanth, and S. Banerjee, Temporal self- similarity of quantum dynamical maps as a concept of memorylessness, Scientific Reports10, 15049 (2020)

  60. [68]

    Dutta, A

    S. Dutta, A. Jain, and P. Mandayam, Smallest quan- tum codes for amplitude damping noise, arXiv preprint arXiv:2410.00155 10.48550/arXiv.2410.00155 (2024)

  61. [69]

    Jayashankar, M

    A. Jayashankar, M. D. H. Long, H. K. Ng, and P. Man- dayam, Achieving fault tolerance against amplitude- damping noise, Phys. Rev. Res.4, 023034 (2022)

  62. [70]

    Knill and R

    E. Knill and R. Laflamme, Theory of quantum error- correcting codes, Physical Review A55, 900 (1997)

  63. [71]

    Ezzell, B

    N. Ezzell, B. Pokharel, L. Tewala, G. Quiroz, and D. A. Lidar, Dynamical decoupling for superconducting qubits: a performance survey, Physical Review Applied 20, 064027 (2023)

  64. [72]

    Viola, E

    L. Viola, E. Knill, and S. Lloyd, Dynamical decoupling of open quantum systems, Physical Review Letters82, 2417 (1999)

  65. [73]

    M. J. Biercuk, H. Uys, A. P. VanDevender, N. Shiga, W. M. Itano, and J. J. Bollinger, Optimized dynamical decoupling in a model quantum memory, Nature458, 996 (2009)

  66. [74]

    Khodjasteh and D

    K. Khodjasteh and D. A. Lidar, Fault-tolerant quantum dynamical decoupling, Physical review letters95, 180501 (2005)

  67. [75]

    De Lange, Z

    G. De Lange, Z. Wang, D. Riste, V. Dobrovitski, and R. Hanson, Universal dynamical decoupling of a single solid-state spin from a spin bath, Science330, 60 (2010)

  68. [76]

    J. Du, X. Rong, N. Zhao, Y. Wang, J. Yang, and R. Liu, Preserving electron spin coherence in solids by optimal dynamical decoupling, Nature461, 1265 (2009)

  69. [77]

    G. A. Álvarez and D. Suter, Measuring the spectrum of colored noise by dynamical decoupling, Physical review letters 107, 230501 (2011)

  70. [78]

    Viola and E

    L. Viola and E. Knill, Robust dynamical decoupling of quantum systems with bounded controls, Physical review letters 90, 037901 (2003)

  71. [79]

    Medford, Ł

    J. Medford, Ł. Cywiński, C. Barthel, C. Marcus, M. Han- son, and A. Gossard, Scaling of dynamical decoupling for spin qubits, Physical review letters108, 086802 (2012)

  72. [80]

    Khodjasteh and D

    K. Khodjasteh and D. A. Lidar, Performance of deter- ministic dynamical decoupling schemes: Concatenated and periodic pulse sequences, Physical Review A 75, 062310 (2007)

  73. [81]

    Facchi, D

    P. Facchi, D. Lidar, and S. Pascazio, Unification of dy- namical decoupling and the quantum zeno effect, Physi- cal Review A69, 032314 (2004)

  74. [82]

    Setiawan and C

    F. Setiawan and C. McLauchlan, Tailoring dynamical codes for biased noise: The X 3Z3 floquet code, arXiv preprint arXiv:2411.04974 10.48550/arXiv.2411.04974 (2024)

  75. [83]

    Alizadeh, J.-P

    F. Alizadeh, J.-P. A. Haeberly, and M. L. Overton, Complementarity and nondegeneracy in semidefinite pro- gramming, Mathematical programming77, 111 (1997)

  76. [84]

    Bharti, M

    K. Bharti, M. Ray, A. Varvitsiotis, N. A. Warsi, A. Ca- bello, and L.-C. Kwek, Robust self-testing of quantum systems via noncontextuality inequalities, Physical re- view letters122, 250403 (2019)

  77. [85]

    Watrous, The theory of quantum information (Cam- bridge university press, 2018)

    J. Watrous, The theory of quantum information (Cam- bridge university press, 2018). Appendix A: Static QECC Optimization Encoding C(0) Decoding D C(0) D ρ E (0) ρ ∣0⟩ FIG. 4. Static QECC illustration. A static code is defined by an encoderC(0) ∶ L(L) → L(A0) and decoder D∶ L(A...

  78. [86]

    An illustration of this scenario for a three-round strategic code is shown in Fig

    Purified dynamics of strategic code and noise First, we explicitly derive the purification of the in- terrogator Tm given a memory trajectory m and noise E which gives a purified dynamics E∗ Tm that maps input maximally entangled state ∣ϕ⟩ to a global pure state ∣E∗ Tm(ϕ)⟩. An...

  79. [87]

    Proof of Theorem 5 Theorem 5 states that ifS(ρR m)+S(ρBlE m )−S(ρRBlE m )< ε for each value of m, then then the entanglement fi- delity between the recovered codestateσRQ0 and the ini- tial codestate∣ϕ⟩RQ0 is bounded as Fent(σRQ0 ,∣ϕ⟩RQ0)≥ 1− 2√ε. Proof. Note that ε> S(ρR m)+ ...

Pith tools

Reviewed August 7, 2026 · model on record in the stance chip above.