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REVIEW 3 major objections 5 minor 59 references

Stream Decoding with Confidence Scores at Room and Cryogenic Temperatures

T0 review · 3 major / 5 minor · reviewed 2026-08-12 · deepseek-v4-flash

Pith's one-line read A streaming Union-Find decoder on an FPGA decodes a surface-code syndrome round in under a microsecond for code distances up to 21.

desk verdict Real cryogenic FPGA decoder work with honest limitations, but the sub-microsecond d=21 claim is extrapolation, not measurement. read the letter →

arxiv 2608.10576 v1 pith:CDFNZBXR submitted 2026-08-11 quant-ph cs.DC

classification quant-phcs.DC PACS 03.67.Pp
keywords quantumerrorcorrectionsurfacecodeUnion-FinddecoderstreamingdecodingFPGAcryogenicelectronicsconfidencescorereal-time
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

The paper aims to establish that Snowflake, a round-wise streaming Union-Find decoder for the surface code, can run on commercial FPGAs fast enough for real-time fault-tolerant quantum computing. The authors report an average per-round decoding time below one microsecond for code distances up to $d=21$ in simulation, satisfying the real-time budget for superconducting qubits, and validate the same design on hardware for distances 3 to 9 at both room and cryogenic temperatures. They also add a decoder confidence score, the Cluster Size 1-Norm Fraction, with no added latency and negligible resource cost, and propose a flattened 2D architecture that reduces the logic footprint by a factor of about the code distance while implementing the same algorithm exactly. If correct, this makes a single small FPGA a viable tier-1 decoder with soft output for a superconducting quantum processor.

What carries the argument

The load-bearing object is Snowflake's decoding window, a fixed-size connected subgraph of the surface-code decoding graph containing $d^2(d+1)$ nodes; the window slides upward by one layer per measurement round (a “drop”), and clusters grow and merge within it according to a Union-Find schedule. The hardware maps each node to a small finite-state-machine processing element and each edge to a communication link, with edge variables (growth and correction) kept in a global register array; a central controller issues the drop-grow-merge commands. The confidence machinery is the Cluster Size 1-Norm Fraction, obtained by summing growth variables in the edge table, which quantifies the total cluster volume in the window and is computed in the idle time between drops. The proposed 2D architecture replaces the full $d^2(d+1)$-node network with a $d\times d$ grid of column processors plus memory, processing one horizontal sheet of the window at a time; active-depth measurements show most nodes are idle most of the time, so early stopping at the active depth is exact, not approximate.

What would settle it

Run the Verilog design for $d=11$ through place-and-route on the same FPGA family at a 200 MHz constraint; if timing closure fails or the measured average decode time per round exceeds 1 microsecond, the central extrapolation is refuted.

Watch

Extended reading notes

Core claim

On the paper's own terms, the central claim is that Snowflake's inherently parallel decoding window maps naturally onto an FPGA fabric: every node of the fixed-size decoding window becomes a processing element and every edge a communication link, so the drop-grow-merge cycle runs as a distributed synchronous process at 200 MHz. With this implementation, simulated code distances up to $d=21$ decode each stabiliser-measurement round in sub-microsecond average time, meeting the 1 microsecond inverse-throughput budget for superconducting devices. Physical hardware tests for $d=3$ to 9 at room and cryogenic temperatures confirm the design operates correctly, though the $d=9$ build exceeded the FPGA's LUT capacity and required an area-optimised variant running at 60 MHz. The same circuit computes the Cluster Size 1-Norm Fraction confidence score between drop cycles at no timing overhead, and the authors further propose a 2D slice-processing architecture that would cut logic usage by a factor of $d$ and enable offload of distant decoding-window data to high-speed memory.

Load-bearing premise

The sub-microsecond decoding claim for distances 11 to 21 rests on a simulated 200 MHz design, even though the largest hardware build (distance 9) already overflowed the FPGA's logic and had to run at 60 MHz.

Editorial extensions

If this is right

  • A single commercial FPGA running Snowflake clears the 1 microsecond per-round budget for distances up to $d=21$, so streaming decoding can coexist with fast superconducting readout.
  • Decoder confidence scores come essentially for free in this architecture, enabling decoder switching or postselection without sacrificing throughput.
  • Cryogenic operation works, but heat from a highly utilised FPGA at the 4 K stage is substantial, so large-scale deployments would move to higher-temperature stages or clusters.
  • The 2D slice architecture reduces logic resource use by roughly a factor of $d$, making Snowflake practical on smaller FPGAs or as the basis for a custom cryo-CMOS ASIC.
  • Early-stop logic based on active depth is exact—skipping deeper sheets never changes the decoder output—so the 2D design gains speed without losing accuracy.

Reading between the lines

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

  • The active-depth result suggests the decoding window height could be made adaptive per noise realisation, shrinking the window when defects are shallow; the paper fixes the window size and only stops early.
  • The confidence score's negligible overhead generalises naturally: any local decoding graph whose edge variables are already in registers could emit a cluster-volume score, so the idea may transfer to other hardware decoders.
  • A memory-bound 2D design raises a new bottleneck the paper does not quantify: if the high-speed bus or DRAM bandwidth cannot feed sheets fast enough at 200 MHz, the factor-of-$d$ saving in logic will be traded for a memory-bandwidth ceiling.
  • Clusters of small FPGAs at the 50 K stage might be tested end-to-end with a realistic syndrome stream; the paper identifies the direction but stops short of a benchmark.
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Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

3 major / 5 minor

Summary. This paper presents an FPGA implementation of the Snowflake streaming Union–Find decoder for the unrotated surface code, augmented with three decoder confidence scores, and evaluates it at both room temperature and inside a cryostat. The authors report resource utilisation for code distances d=3–9, measured decoding throughput, and cryogenic power and temperature data. For d=11–21 they simulate decoding times at a target clock frequency of 200 MHz and claim a sub-microsecond average decoding time per stabiliser measurement round, which they argue satisfies the 1 µs real-time budget for superconducting quantum devices. They also propose a 2D time-multiplexed architecture intended to reduce resource usage, supported by an analysis of 'active depth' and by pseudocode.

Significance. If the extrapolation were backed by timing closure, the sub-microsecond streaming decoder claim would be a significant result for real-time quantum error correction. The measured hardware results for d=3–9, the cryogenic power characterisation, and the confidence-score implementation with negligible latency overhead are useful engineering contributions, and the external benchmarking against Helios, AQ2-RT, and QUEKUF is valuable. The active-depth analysis and the proposed 2D architecture are also interesting. However, the headline claim as stated in Section 4.2 is not supported by the presented evidence: the d=11–21 points are simulated at an assumed clock frequency, while the only d=9 hardware implementation runs at 60 MHz and already exceeds the 1 µs budget. The manuscript should either provide timing-closure evidence for the larger designs or explicitly reframe the claim as an extrapolation.

major comments (3)
  1. [Section 4.2, Figure 6] The statement that 'Snowflake achieves a sub-microsecond average decoding time for code distances up to d=21' is not supported by the hardware evidence. The d=11–21 curve is a cycle-count simulation evaluated at an assumed 200 MHz clock; no placed-and-routed results or timing closure are shown for these distances. The only d=9 hardware result, from the area-optimised design, runs at 60 MHz and yields 1.06 µs per round (Section 4.3), already above the 1 µs budget. The claim should be reworded to distinguish demonstrated hardware performance (d=3–9, with d=9 above the budget) from extrapolated simulation, or the extrapolation should be removed from the abstract and conclusions.
  2. [Section 4.1, Table 1] The resource-scaling data directly conflict with the plausibility of the 200 MHz target at large distances. The d=9 design already exceeds the XCKU5P LUT capacity (237,929 LUTs), and the area-optimised variant that fits still runs at only 60 MHz. Since the number of processing elements scales as d^2(d+1), the d=11–21 designs would require many millions of LUTs, beyond any current FPGA; the paper itself concedes this in the abstract and in Section 5. The simulation should therefore be presented as an algorithmic extrapolation under an explicit assumption that the clock target is met, not as an achieved hardware result.
  3. [Section 4.2, QUEKUF comparison] The estimate that QUEKUF crosses the 1 µs threshold at d≥11 assumes a constant clock frequency of 247.5 MHz, equal to the maximum reported at d=10. This optimistic assumption is stated in the text, but the comparison is used to position Snowflake's extrapolated performance; the same standard of evidence should be applied to both decoders. Please add a sentence noting that the QUEKUF figures are estimates under a favourable clock assumption, and consider showing sensitivity to the clock frequency.
minor comments (5)
  1. [Figure 6] The axis labels in Figure 6 appear garbled in the manuscript; please ensure that the fonts and symbols render correctly in the final version.
  2. [Section 4.2] The sentence 'the architecture leaves ample room for further timing optimisation' is an unsupported assertion; consider replacing it with a discussion of the specific critical-path bottlenecks that limited the area-optimised d=9 design to 60 MHz.
  3. [Section 3.2] The claim that the confidence-score logic has 'minimal impact on the resource utilisation' is not quantified; state explicitly whether Table 1 includes the DCS logic and report the incremental LUT and FF counts attributable to the three DCS implementations.
  4. [Abstract and Section 4.2] The abstract carefully says the results 'when extrapolated' remain within acceptable limits, but Section 4.2 states the sub-microsecond figure as an achieved value; the body should consistently use the same qualifier for all distances above the hardware-validated range.
  5. [Section 4.3] The sentence 'This amounts to a ∼47% reduction in power draw at cryogenic temperatures compared to the XCKU5P FPGA' is ambiguous: the comparison appears to be between the Artix-7 d=3 implementation and the XCKU5P d=3 implementation, and this should be stated explicitly.

Circularity Check

0 steps flagged · score 1.0 of 10

No significant circularity; the central hardware result is benchmarked externally, and the d=11-21 sub-microsecond claim is an explicitly labelled extrapolation rather than a tautological reduction.

full rationale

The paper's substantive claims are not derived from their own inputs by construction. The FPGA hardware implementation is compared against external decoders (AQ2/AQ2-RT, QUEKUF, Helios) in Section 4.2, and the primary decoder confidence score is attributed to an independent reference ([23]) rather than to the authors' own prior work. Cryogenic operation is benchmarked against externally characterized FPGA behavior ([49-52]). The d=11-21 sub-microsecond figure is a cycle-count simulation multiplied by an assumed 200 MHz clock period; it is presented as an extrapolation ('when extrapolated' in the abstract) and is not a fitted parameter renamed as a prediction. The agreement of the hardware simulation with the same-author software analogue [1] is a self-consistency check, not a load-bearing derivation, and the same-author localuf package [55] is used only for the ancillary active-depth analysis. The Lemma imported from [54] is a stated prior mathematical result, not a uniqueness argument used to forbid alternatives, and no ansatz is smuggled in via citation. The main weakness of the paper is that the largest-distance throughput claim rests on an unvalidated clock-frequency assumption and lacks timing closure — a correctness/evidence risk, not circularity. Appendix B's logarithmic fit is descriptive and is not used to generate a predicted quantity that is then reported as an independent result. No specific reduction of a claimed result to its inputs was found.

Assumptions & free parameters 1 free parameters · 5 assumptions · 0 invented entities

Central claim relies on prior Snowflake algorithm correctness and on the circuit-level noise model from [54]; throughput extrapolation additionally assumes a 200 MHz clock remains reachable for d>9, which is unverified and contradicted by the d=9 experience. The active-depth scaling law is fitted to the authors' own simulator.

free parameters (1)
  • active-depth log-law coefficients alpha, beta = alpha = -1.3(1), beta = 3.09(9)
    Appendix B fits the mean active depth versus code distance to D = alpha + beta log10(d); used only to motivate the 2D architecture, not the central throughput claim.
assumptions (5)
  • domain assumption Snowflake as specified in [1] is a correct streaming decoder with the properties used here
    The paper implements rather than re-derives the algorithm; any bug or incorrectness in [1] would invalidate the hardware behavior and the 2D architecture's exactness.
  • ad hoc to paper A target 200 MHz clock frequency remains achievable for code distances d=11 to 21
    The d<=21 sub-microsecond claim is a 200 MHz simulation; the d=9 hardware design exceeded available LUTs and ran at 60 MHz, so scaling to 200 MHz is not demonstrated (Sections 4.1 and 4.2).
  • domain assumption The circuit-level noise model of [54, Section B] at p=10^-3 is representative for throughput and active-depth studies
    Used to generate 1024-round syndrome streams in Section 4.2 and Figure 9; decoder timing can depend on spatiotemporal error density.
  • standard math Lemma 1 from [54, Section A.2] (inactive iff even defect count or touches boundary) holds
    Invoked in Appendix C.4.2 to decide cluster activity in the 2D pseudocode.
  • domain assumption Commercial FPGAs and the custom LDO regulator operate correctly at cryogenic temperatures as prior work suggests
    Sections 3.3 and 3.4 rely on prior demonstrations [49-53]; the temperature diode calibration and rail temperatures are used to validate operation.

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Cite this review

Pith. "Pith review of Stream Decoding with Confidence Scores at Room and Cryogenic Temperatures." pith.science (2026). https://pith.science/paper/CDFNZBXR

@misc{pith2026260810576,
  author       = {Pith},
  title        = {Pith review of: Stream Decoding with Confidence Scores at Room and Cryogenic Temperatures},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/CDFNZBXR}},
  note         = {Machine review of arXiv:2608.10576}
}
read the original abstract

In fault-tolerant quantum computing, fast and accurate decoding is crucial. Snowflake is a decoder for the surface code that runs in a streaming fashion. In this paper, we implement Snowflake on commercial FPGAs and validate them at room and cryogenic temperatures. Our results demonstrate high decoding throughput for small code distances that, when extrapolated, remains within acceptable limits for larger distances. Further, we incorporate the calculation of certain decoder confidence scores with negligible overhead both in terms of latency and physical resource utilisation. We note that implementing a large-scale system would require either a large FPGA beyond today's technology or clusters of FPGAs connected via a high-speed bus. Thus, we discuss an alternative architecture that exploits the locality of Snowflake by processing 2D slices of the 3D decoding window and offloading segments of the 3D structure to a high-speed memory.

Figures

Figures reproduced from arXiv: 2608.10576 by the authors.

Figure 2
Figure 2. Simplified state transition diagram for Snowflake [PITH_FULL_IMAGE:figures/full_fig_p003_2.png] view at source ↗
Figure 1
Figure 1. Schematics relating to Snowflake configured for [PITH_FULL_IMAGE:figures/full_fig_p003_1.png] view at source ↗
Figure 3
Figure 3. Custom printed circuit boards featuring onboard [PITH_FULL_IMAGE:figures/full_fig_p004_3.png] view at source ↗
Figures from the paper (9 more)
Figure 4
Figure 4. Figure 4: Measurement setup featuring both FPGA modules [PITH_FULL_IMAGE:figures/full_fig_p005_4.png]
Figure 6
Figure 6. Figure 6: Mean duration to decode per stabiliser measure [PITH_FULL_IMAGE:figures/full_fig_p006_6.png]
Figure 7
Figure 7. Figure 7: Impact of code distance (d) on decoder power con￾sumption at room (Prt) and cryogenic (Pcryo) temperatures, along with the corresponding XCKU5P FPGA die (Tdie) and cryostat (Trail) temperatures. The findings indicate that operating the FPGA in a cryogenic environment c…
Figure 8
Figure 8. Figure 8: (a) A flattened implementation of Snowflake in [PITH_FULL_IMAGE:figures/full_fig_p008_8.png]
Figure 10
Figure 10. Figure 10: An architecture for the flattened implementation [PITH_FULL_IMAGE:figures/full_fig_p009_10.png]
Figure 11
Figure 11. Figure 11: The same data as in [PITH_FULL_IMAGE:figures/full_fig_p012_11.png]
Figure 12
Figure 12. Figure 12: Flowchart for the stages of Snowflake: drop, grow whole, and grow half are of fixed duration whereas the other two last a variable duration, hence their loops. At a high level, the following processes occur in each stage. In drop, the decoding window W slides up the d…
Figure 13
Figure 13. Figure 13: An example of a decoding cycle (Definition 3) that takes 6 timesteps (Definition 2), for a distance-3 repetition code. Ungrown edges are invisible; half-grown, dotted; fully grown, solid. Edges flipped by the decoder are in black. Active nodes are squares; inactive no…
Figure 14
Figure 14. Figure 14: A demonstration of unrooting on the distance-2 [PITH_FULL_IMAGE:figures/full_fig_p015_14.png]

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Reference graph

Works this paper leans on

59 extracted references · 44 canonical work pages

  1. [1]

    Snowflake: A distributed streaming decoder

    Tim Chan. “Snowflake: A distributed streaming decoder”. Quantum10, 2033 (2026)

  2. [2]

    Scheme for reducing decoher- ence in quantum computer memory

    Peter W. Shor. “Scheme for reducing decoher- ence in quantum computer memory”. Physical Review A52, R2493–R2496 (1995). 9

  3. [3]

    Fault-tolerant quantum compu- tation

    John Preskill. “Fault-tolerant quantum compu- tation”. Introduction to quantum computation and information213(1998)

  4. [4]

    Quantum error correction for quantum memories

    Barbara M. Terhal. “Quantum error correction for quantum memories”. Rev. Mod. Phys.87, 307–346 (2015)

  5. [5]

    Sur- face codes: Towards practical large-scale quan- tum computation

    Austin G. Fowler, Matteo Mariantoni, John M. Martinis, and Andrew N. Cleland. “Sur- face codes: Towards practical large-scale quan- tum computation”. Physical Review A86, 032324 (2012)

  6. [6]

    Topological quantum mem- ory

    Eric Dennis, Alexei Kitaev, Andrew Landahl, and John Preskill. “Topological quantum mem- ory”. Journal of Mathematical Physics43, 4452– 4505 (2002)

  7. [7]

    A game of surface codes: Large- scale quantum computing with lattice surgery

    Daniel Litinski. “A game of surface codes: Large- scale quantum computing with lattice surgery”. Quantum3, 128 (2019)

  8. [8]

    A case for elastic quantum error correction decoders

    Satvik Maurya, Abtin Molavi, Aws Albargh- outhi, and Swamit Tannu. “A case for elastic quantum error correction decoders”. In Pro- ceedings of the 21st European Conference on Computer Systems. Pages 514–531. EUROSYS ’26New York, NY, USA (2026). Association for Computing Machinery

Show all 59 references
  1. [9]

    Real-time decoding for fault-tolerant quantum computing: progress, challenges and outlook

    Francesco Battistel, Christopher Chamberland, Kauser Johar, Ramon W. J. Overwater, Fabio Sebastiano, Luka Skoric, Yosuke Ueno, and Muhammad Usman. “Real-time decoding for fault-tolerant quantum computing: progress, challenges and outlook”. Nano Futures7, 032003 (2023)

  2. [10]

    Suppressing quantum er- rors by scaling a surface code logical qubit

    Google Quantum AI. “Suppressing quantum er- rors by scaling a surface code logical qubit”. Na- ture614, 676–681 (2023)

  3. [11]

    Quan- tum error correction below the surface code threshold

    Google Quantum AI and collaborators. “Quan- tum error correction below the surface code threshold”. Nature638, 920–926 (2025)

  4. [12]

    A fault-tolerant neutral-atom architecture for universal quantum computation

    Dolev Bluvstein, Alexandra A. Geim, Sophie H. Li, Simon J. Evered, J. Pablo Bonilla Ataides, Gefen Baranes, Andi Gu, Tom Manovitz, Muqing Xu, Marcin Kalinowski, Shayan Ma- jidy, Christian Kokail, Nishad Maskara, Elias C. Trapp, Luke M. Stewart, Simon Hollerith, Hengyun Zhou, M...

  5. [13]

    Time-optimal quantum com- putation

    Austin G. Fowler. “Time-optimal quantum com- putation” (2013). arXiv:1210.4626

  6. [14]

    How to factor 2048 bit rsa integers in 8 hours using 20 million noisy qubits

    Craig Gidney and Martin Eker ˚ a. “How to factor 2048 bit rsa integers in 8 hours using 20 million noisy qubits”. Quantum5, 433 (2021)

  7. [15]

    A scalable and real-time neural decoder for topological quantum codes

    Andrew W. Senior, Thomas Edlich, Francisco J. H. Heras, Lei M. Zhang, Oscar Higgott, James S. Spencer, Taylor Applebaum, Sam Blackwell, Justin Ledford, Akvil˙ e ˇZemgulyt˙ e, Augustin ˇZ ´ ıdek, Noah Shutty, Andrew Cowie, Yin Li, George Holland, Peter Brooks, Charlie Beattie, ...

  8. [16]

    How to factor 2048 bit RSA inte- gers with less than a million noisy qubits

    Craig Gidney. “How to factor 2048 bit RSA inte- gers with less than a million noisy qubits” (2025). arXiv:2505.15917

  9. [17]

    Accelerating the tesseract de- coder for quantum error correction

    Dragana Grbic, Laleh Aghababaie Beni, and Noah Shutty. “Accelerating the tesseract de- coder for quantum error correction” (2026). arXiv:2602.02985

  10. [18]

    Decoder switching: Breaking the speed- accuracy tradeoff in real-time quantum error cor- rection

    Riki Toshio, Kaito Kishi, Jun Fujisaki, Hiro- taka Oshima, Shintaro Sato, and Keisuke Fu- jii. “Decoder switching: Breaking the speed- accuracy tradeoff in real-time quantum error cor- rection” (2025). arXiv:2510.25222

  11. [19]

    Mitigating errors in logical qubits

    Samuel C. Smith, Benjamin J. Brown, and Stephen D. Bartlett. “Mitigating errors in logical qubits”. Communications Physics7, 386 (2024)

  12. [20]

    Fault-tolerant postselec- tion for low-overhead magic state preparation

    H´ ector Bomb ´ ın, Mihir Pant, Sam Roberts, and Karthik I. Seetharam. “Fault-tolerant postselec- tion for low-overhead magic state preparation”. PRX Quantum5, 010302 (2024)

  13. [21]

    Efficient soft-output decoders for the surface code

    Nadine Meister, Christopher A. Pattison, and John Preskill. “Efficient soft-output decoders for the surface code” (2024). arXiv:2405.07433

  14. [22]

    Yoked surface codes

    Craig Gidney, Michael Newman, Peter Brooks, and Cody Jones. “Yoked surface codes”. Nature Communications16, 4498 (2025)

  15. [23]

    Efficient post-selection for general quantum LDPC codes

    Seok-Hyung Lee, Lucas H. English, and Stephen D. Bartlett. “Efficient post-selection for general quantum LDPC codes”. npj Quantum Information12(2026)

  16. [24]

    Error mitigation of fault-tolerant quantum circuits with soft infor- mation

    Zeyuan Zhou, Shaun Pexton, Aleksander Ku- bica, and Yongshan Ding. “Error mitigation of fault-tolerant quantum circuits with soft infor- mation” (2025). arXiv:2512.09863

  17. [25]

    Error mitigation for logical circuits using decoder confidence

    Maria Dinc˘ a, Tim Chan, and Simon C. Ben- jamin. “Error mitigation for logical circuits using decoder confidence” (2026). arXiv:2512.15689

  18. [26]

    Macro- mux: scalable postselection for high-threshold fault-tolerant quantum computation

    Patrick Birchall, Jacob Bridgeman, Christo- pher Dawson, Terry Farrelly, Yehua Liu, Naomi Nickerson, Mihir Pant, Sam Roberts, Karthik Seetharam, and David Tuckett. “Macro- mux: scalable postselection for high-threshold fault-tolerant quantum computation” (2026). arXiv:2603.04875

  19. [27]

    Scalable accuracy gains from postselection in quantum error cor- recting codes

    Hongkun Chen, Daohong Xu, Grace M. Som- mers, David A. Huse, Jeff D. Thompson, and Sarang Gopalakrishnan. “Scalable accuracy gains from postselection in quantum error cor- recting codes” (2025). arXiv:2510.05222

  20. [28]

    Neural network decoder confidence as a learned proxy for the logical gap

    David Dentelski. “Neural network decoder confidence as a learned proxy for the logical gap” (2026). arXiv:2606.08758. 10

  21. [29]

    Adaptive window decoding based on spatiotemporal complementary gap

    Moeto Mishima, Riki Toshio, Kaito Kishi, Jun Fujisaki, Hirotaka Oshima, Shintaro Sato, and Keisuke Fujii. “Adaptive window decoding based on spatiotemporal complementary gap” (2026). arXiv:2605.14637

  22. [30]

    Scalable postselection of quantum resources

    J. Wilson Staples, Winston Fu, and Jeff D. Thompson. “Scalable postselection of quantum resources” (2026). arXiv:2603.08697

  23. [31]

    A quantum engineer’s guide to superconducting qubits

    P. Krantz, M. Kjaergaard, F. Yan, T. P. Orlando, S. Gustavsson, and W. D. Oliver. “A quantum engineer’s guide to superconducting qubits”. Ap- plied Physics Reviews6(2019)

  24. [32]

    Interfacing spin qubits in quantum dots and donors—hot, dense, and coherent

    L. M. K. Vandersypen, H. Bluhm, J. S. Clarke, A. S. Dzurak, R. Ishihara, A. Morello, D. J. Reilly, L. R. Schreiber, and M. Veldhorst. “Interfacing spin qubits in quantum dots and donors—hot, dense, and coherent”. npj Quan- tum Information3(2017)

  25. [33]

    The electronic interface for quantum proces- sors

    J.P.G. van Dijk, E. Charbon, and F. Sebastiano. “The electronic interface for quantum proces- sors”. Microprocessors and Microsystems66, 90– 101 (2019)

  26. [34]

    QECOOL: On-line quantum error correction with a superconducting decoder for surface code

    Yosuke Ueno, Masaaki Kondo, Masamitsu Tanaka, Yasunari Suzuki, and Yutaka Tabuchi. “QECOOL: On-line quantum error correction with a superconducting decoder for surface code”. In 2021 58th ACM/IEEE Design Automa- tion Conference (DAC). Pages 451–456. (2021)

  27. [35]

    QULATIS: A quantum error correction method- ology toward lattice surgery

    Yosuke Ueno, Masaaki Kondo, Masamitsu Tanaka, Yasunari Suzuki, and Yutaka Tabuchi. “QULATIS: A quantum error correction method- ology toward lattice surgery”. In 2022 IEEE International Symposium on High-Performance Computer Architecture (HPCA). Pages 274–287. (2022)

  28. [36]

    NISQ+: boosting quan- tum computing power by approximating quan- tum error correction

    Adam Holmes, Mohammad Reza Jokar, Ghasem Pasandi, Yongshan Ding, Massoud Pedram, and Frederic T. Chong. “NISQ+: boosting quan- tum computing power by approximating quan- tum error correction”. In Proceedings of the ACM/IEEE 47th Annual International Sympo- sium on Computer Arc...

  29. [37]

    Pinball: A cryogenic predecoder for quan- tum error correction decoding under circuit-level noise

    Alexander Knapen, Guanchen Tao, Jacob Mack, Tomas Bruno, Mehdi Saligane, Dennis Sylvester, Qirui Zhang, and Gokul Subramanian Ravi. “Pinball: A cryogenic predecoder for quan- tum error correction decoding under circuit-level noise”. In 2026 IEEE International Sympo- sium on Hi...

  30. [38]

    Mitigating classical resource costs in quantum error correction via generalized qLDPC predecoding

    Alexander Knapen, Junyi Luo, Guanchen Tao, Yuxuan Wang, Tomas Bruno, Qirui Zhang, Den- nis Sylvester, Mehdi Saligane, and Gokul Sub- ramanian Ravi. “Mitigating classical resource costs in quantum error correction via generalized qLDPC predecoding” (2026). arXiv:2605.03180

  31. [39]

    Real-time surface-code error correction using an FPGA-based neural-network decoder

    Xiaohan Yang, Xuandong Sun, Zhiyi Wu, Jiawei Zhang, Ji Jiang, Xiayu Linpeng, Yuxuan Zhou, Ji Chu, Jingjing Niu, Youpeng Zhong, Song Liu, and Dapeng Yu. “Real-time surface-code error correction using an FPGA-based neural-network decoder” (2026). arXiv:2605.04892

  32. [40]

    Re- think the role of neural decoders in quantum er- ror correction

    Ge Yan, Shanchuan Li, and Yuxuan Du. “Re- think the role of neural decoders in quantum er- ror correction” (2026). arXiv:2605.12046

  33. [41]

    A scalable FPGA architecture for real-time decoding of quantum LDPC codes using GARI

    Daniel B´ ascones, Arshpreet Singh Maan, Valentin Savin, and Francisco Garcia-Herrero. “A scalable FPGA architecture for real-time decoding of quantum LDPC codes using GARI” (2026). arXiv:2605.01035

  34. [42]

    Zero-G: A pre-decoder-aware decoder for quantum error correction

    Peter Wegmann, Theofilos Augoustis, Aleksan- dra ´Swierkowska, Emmanouil Giortamis, and Pramod Bhatotia. “Zero-G: A pre-decoder-aware decoder for quantum error correction” (2026). arXiv:2608.02030

  35. [43]

    FPGA-based distributed union-find decoder for surface codes

    Namitha Liyanage, Yue Wu, Siona Tagare, and Lin Zhong. “FPGA-based distributed union-find decoder for surface codes”. IEEE Transactions on Quantum Engineering5, 1–18 (2024)

  36. [44]

    Lo- cal clustering decoder as a fast and adaptive hardware decoder for the surface code

    Abbas B. Ziad, Ankit Zalawadiya, Can- berk Topal, Joan Camps, Gy¨ orgy P. Geh´ er, Matthew P. Stafford, and Mark L. Turner. “Lo- cal clustering decoder as a fast and adaptive hardware decoder for the surface code”. Nature Communications16, 11048 (2025)

  37. [45]

    QUEKUF: An FPGA union find de- coder for quantum error correction on the toric code

    Federico Valentino, Beatrice Branchini, Davide Conficconi, Donatella Sciuto, and Marco D. San- tambrogio. “QUEKUF: An FPGA union find de- coder for quantum error correction on the toric code”. ACM Trans. Reconfigurable Technol. Syst.18(2025)

  38. [46]

    Micro Blossom: Accelerated minimum-weight perfect matching decoding for quantum error cor- rection

    Yue Wu, Namitha Liyanage, and Lin Zhong. “Micro Blossom: Accelerated minimum-weight perfect matching decoding for quantum error cor- rection”. In Proceedings of the 30th ACM In- ternational Conference on Architectural Support for Programming Languages and Operating Sys- tems, ...

  39. [47]

    Linear-time maximum likelihood decoding of surface codes over the quantum erasure channel

    Nicolas Delfosse and Gilles Z´ emor. “Linear-time maximum likelihood decoding of surface codes over the quantum erasure channel”. Physical Re- view Research2, 033042 (2020)

  40. [48]

    Almost-linear time decoding algorithm for topo- logical codes

    Nicolas Delfosse and Naomi H. Nickerson. “Almost-linear time decoding algorithm for topo- logical codes”. Quantum5, 595 (2021)

  41. [49]

    Perfor- mance characterization of Altera and Xilinx 28 nm FPGAs at cryogenic temperatures

    Harald Homulle and Edoardo Charbon. “Perfor- mance characterization of Altera and Xilinx 28 nm FPGAs at cryogenic temperatures”. In 2017 International Conference on Field Programmable Technology (ICFPT). Pages 25–31. (2017)

  42. [50]

    Cryogenic characterization of commercial devices for application of quantum 11 computing electronics

    Zhanhong Jin, Xinzhe Wang, Futian Liang, and Cheng-Zhi Peng. “Cryogenic characterization of commercial devices for application of quantum 11 computing electronics”. In 2022 IEEE 65th In- ternational Midwest Symposium on Circuits and Systems (MWSCAS). Pages 1–5. (2022)

  43. [51]

    Implementation of field pro- grammable gate arrays (FPGAs) in extremely cold environments for space and cryogenic com- puting applications

    Christopher Lewis, Drew Sellers, and Michael Hamilton. “Implementation of field pro- grammable gate arrays (FPGAs) in extremely cold environments for space and cryogenic com- puting applications” (2025). arXiv:2504.13305

  44. [52]

    An fpga-based instrumentation platform for use at deep cryo- genic temperatures

    I. D. Conway Lamb, J. I. Colless, J. M. Horni- brook, S. J. Pauka, S. J. Waddy, M. K. Frechtling, and D. J. Reilly. “An fpga-based instrumentation platform for use at deep cryo- genic temperatures”. Review of Scientific Instru- ments87(2016)

  45. [53]

    Cryo- genic low-dropout voltage regulators for stable low-temperature electronics

    Harald Homulle and Edoardo Charbon. “Cryo- genic low-dropout voltage regulators for stable low-temperature electronics”. Cryogenics95, 11– 17 (2018)

  46. [54]

    Actis: A strictly local Union–Find decoder

    Tim Chan and Simon C. Benjamin. “Actis: A strictly local Union–Find decoder”. Quantum7, 1183 (2023)

  47. [55]

    url:https://github.com/ timchan0/localuf

    Tim Chan (2023). url:https://github.com/ timchan0/localuf

  48. [56]

    Even more efficient soft-output decoding with extra-cluster growth and early stopping

    Kaito Kishi, Riki Toshio, Jun Fujisaki, Hiro- taka Oshima, Shintaro Sato, and Keisuke Fujii. “Even more efficient soft-output decoding with extra-cluster growth and early stopping” (2026). arXiv:2602.03336

  49. [57]

    Multi-FPGA system for quan- tum error correction with lattice surgery

    Namitha Liyanage, Yue Wu, Emmet Houghton, and Lin Zhong. “Multi-FPGA system for quan- tum error correction with lattice surgery”. In 2024 IEEE International Conference on Quan- tum Computing and Engineering (QCE). Vol- ume 02, pages 622–623. (2024)

  50. [58]

    Network-integrated decoding system for real-time quantum error correction with lattice surgery

    Namitha Liyanage, Yue Wu, Emmet Houghton, and Lin Zhong. “Network-integrated decoding system for real-time quantum error correction with lattice surgery”. In 2025 IEEE International Conference on Quantum Computing and Engi- neering (QCE). Volume 01, pages 1148–1159. (2025)

  51. [59]

    University of Oxford Ad- vanced Research Computing

    Andrew Richards. “University of Oxford Ad- vanced Research Computing”. (2015). A Other Decoder Confidence Scores In this section, we mention two other DCSs with min- imal impact on resource utilisation. These are: 1.Drop Frequency:How fast the decoder gener- ates a correction;...

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