Quantum error correction below the surface code threshold · HackerPapers discussions

Quantum error correction below the surface code threshold — mentioned by Strilanc

Wed, 01 Apr 2026 16:31:47 GMT

> [0.1% gate error rate] is still wildly out of reach This is false. When Fowler et al assumed 0.1% gate error rates would be reached for his estimates in 2012 [0], that was ostentatious. Now it's frankly a bit overly conservative. All the big architectures are approaching or surpassing 0.1% gate error rates. From 2022 to 2024, the google team improved mean two qubit gate error rate from 0.6% [1] to 0.4% [2]. Quantinuum's Helios has a two qubit gate error rate of 0.08% [3]. IBM has Heron processors available on their cloud service with two qubit gate error rates ranging from 0.2% to 0.7% [4].…

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Quantum error correction below the surface code threshold — mentioned by Strilanc

Mon, 11 Aug 2025 13:36:15 GMT

That paper is hilarious, and is correct that there's plenty of shit to make fun of... but there's also progress. I recommend watching Sam Jacques' talk from PQCrypto 2025 [0]. It would be silly to delay PQC adoption because of focusing on the irrelevant bad papers. In the past ten years, on the theory side, the expected cost of cryptographically relevant quantum factoring has dropped by 1000x [1][2]. On the hardware side, fault tolerance demonstrations have gone from repetition code error rates of 1% error per round [3] to 0.00000001% error per round [fig3a of 4], with full quantum codes…

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Quantum error correction below the surface code threshold — mentioned by Strilanc

Mon, 17 Feb 2025 23:13:46 GMT

Using the largest number factored as a benchmark for progress in quantum computing is like evaluating floor(f(0)) = 0 and floor(f(1)) = 0 and concluding f(x) = 0. You can't distinguish f(x) = 0 from f(x) = x/2 from f(x) = e^x/3 when your test is too coarse. If you want to see the progress in quantum computing today, pay attention to component reliability. For example, in 2014, the best rep code run on a quantum computer had a 1% error rate per round [1]. In 2024, it was 0.00000001% and it had become possible to run full quantum codes with a 0.2% error rate per round [2]. If it takes another…

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Quantum error correction below the surface code threshold — HN submission

Tue, 10 Dec 2024 10:44:22 GMT

Quantum error correction below the surface code threshold

3 points; 0 discussion replies on HN. Paper and source history. A submission is not an endorsement.

Quantum error correction below the surface code threshold — mentioned by qnleigh

Mon, 09 Dec 2024 21:54:40 GMT

and the arXiv preprint, which isn't paywalled https://arxiv.org/html/2408.13687v1

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Quantum error correction below the surface code threshold — mentioned by qnleigh

Mon, 09 Dec 2024 21:48:56 GMT

I wouldn't call it extraordinary, as this has been expected since the first quantum error correcting codes were worked out theoretically. But it is a strong claim, backed up with comparably strong evidence. Figure 1d of the paper shows exactly this https://arxiv.org/html/2408.13687v1, and unlike many other comparable works, there are no hat tricks like post-selection to boost the numbers.

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Quantum error correction below the surface code threshold — mentioned by wasabi991011

Mon, 09 Dec 2024 18:56:12 GMT

It does. It's up to engineering to make errors uncorrelated. The google paper being referenced actually makes an "error budget" to see what the main sources of errors are, and also run tests to find sources of correlated errors. The claim about this is that correlated errors will lead to an "error floor", a certain size of error correction past which exponential reduction in errors no longer applies, due to a certain frequency of correlated errors. See figure 3a of the arxiv version of the paper: https://arxiv.org/abs/2408.13687

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Quantum error correction below the surface code threshold — mentioned by radioactivist

Mon, 09 Dec 2024 18:29:47 GMT

Some of these results have been on the arxiv for a few months (https://arxiv.org/abs/2408.13687) -- are there any details on new stuff besides this blog post? I can't find anything on the random circuit sampling in the preprint (or its early access published version).

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Quantum error correction below the surface code threshold — mentioned by winwang

Mon, 09 Dec 2024 17:52:55 GMT

Edit after skimming arxiv preprint[1]: Yeah, this is pretty huge. They achieved the result with surface codes, which are general ECCs. The repetition code was used to further probe quantum ECC floor. "Just POC" likely doesn't do it justice. (Original comment): Also quantum dabbler (coincidentally dabbled in bitflip quantum error correction research). Skimmed the post/research blog. I believe the key point is the scaling of error correction via repetition codes, would love someone else's viewpoint. Slightly concerning quote[2]: """ By running experiments with repetition codes and ignoring…

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Quantum error correction below the surface code threshold — mentioned by bramathon

Fri, 22 Nov 2024 21:39:23 GMT

This is not about AlphaQubit. It's about a different paper, https://arxiv.org/abs/2408.13687 and they do demonstrate real-time decoding. > we show that we can maintain below-threshold operation on the 72-qubit processor even when decoding in real time, meeting the strict timing requirements imposed by the processor’s fast 1.1 μs cycle duration

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Quantum error correction below the surface code threshold — mentioned by kittikitti

Fri, 22 Nov 2024 19:22:50 GMT

This is another hype piece from Google's research and development arm. This is a theoretical application to increase the number of logical qubits in a system by decreasing the error caused by quantum circuts. They just didn't do the last part yet so the application is yet to be seen. https://arxiv.org/abs/2408.13687 "Our results present device performance that, if scaled, could realize the operational requirements of large scale fault-tolerant quantum algorithms." Google forgot to test if it scales I guess?

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Quantum error correction below the surface code threshold — mentioned by terminalbraid

Fri, 22 Nov 2024 18:58:17 GMT

Note the paper they are referring to was published August 27, 2024 https://arxiv.org/pdf/2408.13687

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Quantum error correction below the surface code threshold — mentioned by EvgeniyZh

Fri, 22 Nov 2024 11:17:31 GMT

I'm condensed matter theory PhD student and my research is close but not directly related to quantum computing. There are some usecases for quantum computers and we are pretty sure that QCs are able to do stuff classical ones can't, but it is somewhat limited. In fact there is xprize to think of some applications [1]. You can separate usecases by whether they require fault tolerance. Fault tolerance is still very far away, and even single fault tolerant qubit (error rate of say 10^(-14)) would take a lot time from now, leave alone thousands/millions of them. We only had working error…

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Quantum error correction below the surface code threshold — HN submission

Wed, 25 Sep 2024 22:44:56 GMT

Quantum error correction below the surface code threshold

1 point; 0 discussion replies on HN. Paper and source history. A submission is not an endorsement.

Quantum error correction below the surface code threshold — HN submission

Tue, 24 Sep 2024 16:57:01 GMT

Quantum error correction below the surface code threshold

1 point; 0 discussion replies on HN. Paper and source history. A submission is not an endorsement.

Quantum error correction below the surface code threshold — mentioned by Strilanc

Thu, 12 Sep 2024 19:00:30 GMT

> I have not seen even a theoretical framework allowing both to be increased simultaneously. The threshold theorem [1], showing this can be done in principle, was proven more than a decade ago. But you don't have to believe the theory anymore, there's experiments now! Last month the google quantum computing team published an experiment [2] showing memory error rates (including decoherence) getting twice as good as a surface code was grown from distance 3 to distance 5, and twice as good again going from distance 5 to distance 7. The logical qubit's coherence time was longer than the coherence…

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Quantum error correction below the surface code threshold — mentioned by westurner

Thu, 05 Sep 2024 18:27:04 GMT

"Quantum error correction below the surface code threshold" (2024) https://arxiv.org/abs/2408.13687 : > Abstract: Quantum error correction provides a path to reach practical quantum computing by combining multiple physical qubits into a logical qubit, where the logical error rate is suppressed exponentially as more qubits are added. However, this exponential suppression only occurs if the physical error rate is below a critical threshold. In this work, we present two surface code memories operating below this threshold: a distance-7 code and a distance-5 code integrated with a real-time…

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Quantum error correction below the surface code threshold — HN submission

Tue, 27 Aug 2024 18:53:33 GMT

Google proves Fault-Tolerant Quantum Computing is possible

2 points; 0 discussion replies on HN. Paper and source history. A submission is not an endorsement.

Quantum error correction below the surface code threshold — HN submission

Tue, 27 Aug 2024 09:31:35 GMT

Quantum error correction below the surface code threshold

3 points; 2 discussion replies on HN. Paper and source history. A submission is not an endorsement.