Recent comments from SciRate

Aram Harrow Dec 19 2025 10:33 UTC

Just until this is addressed in v2: loglog(1/eps) depth is Thm 13.5 of the Kitaev-Shen-Vyalyi book. This is overall depth, not just T depth.

Zhenhuan Liu Dec 18 2025 10:04 UTC

Thank you so much. I just realized this!

Michael Dec 18 2025 09:21 UTC

Dear Zhenhuan, if the group only contains the identity, the channel only needs to purify the maximally mixed state (the unique state in the algebra spanned by the group). It achieves this by always outputting the maximally entangled state (regardless of the input state).

Zhenhuan Liu Dec 18 2025 07:40 UTC

Congratulations on the intersting result!

I was wondering the relationship between your result and Theorem 3 in [arXiv:2509.21111][1], which proves the exponential sample complexity lower bound of preparing a single purification state.

Your result seems to hold for all unitary groups. So if th

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Nicolas Delfosse Dec 17 2025 08:13 UTC

If you want to try it yourself Min's implementation of the beam search decoder is now available here: https://github.com/ionq-publications/BeamSearchDecoder

Blake Stacey Dec 17 2025 02:53 UTC

The term *light rectangle* was used [20 years ago by N. David Mermin with the same meaning](https://arxiv.org/pdf/gr-qc/0411069). Mermin also deduces the invariant interval from the area of a light rectangle drawn on the Euclidean plane.

Antonio Anna Mele Dec 17 2025 02:05 UTC

Hi Ben, thanks a lot for your kind words!

Whether "optimal" should be reserved only for results that are tight without logarithmic factors is, we think, still somewhat up for debate. 🙂

For example, one of the two concurrent seminal papers establishing quantum state tomography optimal up to logs w

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Michal Krompiec Dec 16 2025 16:46 UTC

It's great as a quantum-inspired algorithm, but what are the prospects of ever executing this on FTQC, given the scaling of the sampling cost of VQE? I mean, isn't the number of samples required to reach a decent accuracy prohibitively high above ~10 qubits?

Martin Ekerå Dec 16 2025 00:49 UTC

I fail to see a novel contribution in this pre-print. Since Shor put out his groundbreaking paper [[Shor94]](https://doi.org/10.1109/SFCS.1994.365700) [[Shor97]](https://doi.org/10.1137/S0097539795293172) back in 1994 many proposals for improvements have been published. Using divisors of the order $

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Ben Lee Dec 15 2025 09:07 UTC

This is an excellent piece of work, congratulations on the result! I am particularly excited to see query complexity bounds established for general quantum channels, going beyond states and unitaries.

I just wanted to clarify one point. Would it be more appropriate to use the term *near-optimal l

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Zhide Lu Dec 14 2025 15:45 UTC

Congratulations on this nice paper! I have a small query regarding Algorithm 2 (Sliding-Window Decoding), specifically in lines 17 and 18. In the pseudo-code, m_com is passed to the inner DECODE function (line 17), while m_cvg is used to mask the error vector ê (line 18). However, based on the input

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Leo Shaposhnik Dec 13 2025 10:09 UTC

it might be interesting for you to know that somewhat related states were studied here from a different perspective (in particular using continuous groups)
https://arxiv.org/abs/2510.06602

Paweł Cieśliński Dec 11 2025 13:53 UTC

Thanks for the reference!

Sadly, we were not aware of your work. The polygamous behaviour you describe is exactly of our interest. I'll look into that.

Congratulations on the results!

Arthur Mehta Dec 11 2025 13:41 UTC

It is always great to see more work exploring these important properties of non-locality. I wanted to highlight our work from earlier this year studying bipartite monogamy/polygamy. PRR : https://journals.aps.org/prresearch/abstract/10.1103/1m7q-rgrh. (ArXiv version: https://arxiv.org/abs/2405.20286

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Stephen DiAdamo Dec 08 2025 19:31 UTC

Link to the repo: https://github.com/QoroQuantum/maestro

Ben Lee Dec 08 2025 04:29 UTC

The work is interesting, but there are several major issues that make it difficult for me to fully trust the authors’ claims. Clarifying these points would greatly help my understanding.

1. It is unclear whether the experiments were actually conducted according to the definitions proposed in the

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Barbara Terhal Dec 05 2025 06:20 UTC

Without having looked at this paper, the following comments. The fact that one has to use a different norm for errors (diamond norm) for FTQC to cover general errors has been known since Kitaevs papers "Quantum error correction with imperfect gates" and "Quantum computing: algorithms and error corre

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Craig Gidney Dec 04 2025 11:52 UTC

@Mingyu I suspect you made some mistake in the simulation, or were simulating a non-fault-tolerant construction (e.g. the output qubit being a single physical qubit). When I put 5-to-1 simulation into Quirk, I see the same qualitative "continuous perturbations become perturbations with pauses near t

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Aliki Capatos Dec 04 2025 10:16 UTC

Lovely stuff - just wanted to signpost our paper which also considers these errors at the resource state level, applying it to a full architecture scirate.com/arxiv/2507.16152. I'd say our work is most closely aligned with what you talk about, since we don't use polarization encoding and do consider

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Mingyu Kang Dec 04 2025 09:07 UTC

Interesting. I have some old simulation for 5-to-1 distillation that says otherwise (coherent rotations before the MSD circuit is suppressed but not those after it). Thanks for correcting, I might check this out

Craig Gidney Dec 04 2025 08:07 UTC

@Mingyu What? That's definitely false about the 15-to-1 distillation. One of the most common examples I show people when introducing them to Quirk is that if you put global continuous rotations at the end of the 15-to-1 distillation, and then look at the postselected output state, it rotates continu

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Ashutosh Goswami Dec 04 2025 06:17 UTC

Thanks, I'm glad that splitting-up helped!

Ashutosh Goswami Dec 04 2025 06:08 UTC

Hi Craig,
Thanks for the question! Yes, it's not known if A implies B! The problem is not limited to fault-tolerance but also is there in error correction. So let's say A' refers to "a family of error correcting code having error correcting threshold for stochastic noise" and "not B'" refers to "

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Mingyu Kang Dec 04 2025 04:49 UTC

Right... maybe it's related to the difficulty of designing the entire FTQC architecture that works for both stochastic and coherent noise models, which this paper seems to do successfully. I can give you a really dumb example where typical protocols fail under the noise model where you have small an

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Craig Gidney Dec 04 2025 02:42 UTC

But in the context of scaling-with-distance-or-not-with-some-threshold, that distinction shouldn't matter... right? I might need a bigger distance or a stricter threshold to ensure the bound holds despite quadratic growth rather than linear growth, but qualitatively that detail shouldn't be able to

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Mingyu Kang Dec 04 2025 01:30 UTC

I think the concern has been that in a stochastic error model, the error builds up linearly, but in a worst-case coherent error model where error is a sigma_z rotation by some angle theta, error builds up quadratically (p=sin^2(theta) then sin^2(n*theta) ~ n^2*p), so it has been hard to "translate"

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Chris Pattison Dec 03 2025 19:31 UTC

I appreciate the splitting-up of 2408.05260 into two. It's a large paper with lots of results that could be missed. (At least, I missed some of them)

Craig Gidney Dec 03 2025 17:38 UTC

I have a background question: are there any known examples where a circuit is known to be fault tolerant to stochastic noise (call this "A") but not fault tolerant to general noise (call this "not B")?

I ask because I was surprised to learn it wasn't known that the A implies B. My intuition is that

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Stanislaw Wolanski Dec 03 2025 09:47 UTC

Hi Timo,
Thanks for your interest! I’m aware of your work; ultimately I decided to use a distinct name so readers wouldn’t get tripped up by the terminology.

Timo Hillmann Dec 03 2025 09:21 UTC

Interesting work! Just wanting to point out that previously ACID was known as LSD in the community, see here: https://arxiv.org/abs/2406.18655

Anthony O'Rourke Dec 03 2025 03:15 UTC

Congratulations on your paper! It's really nice to see this dense packing simulated. I think there is a small mistake in your Figure 4, namely what constitutes a Z hook error should be parallel with the logical Z operator rather than perpindicular to it. Similarly in Figure 3 if the data qubits c an

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Walden Killick Dec 01 2025 17:09 UTC

Very nice paper! In Section 5.2, you state that

> in lattice surgery each move costs one stabilizer measurement round, independent of distance.

However, if my understanding is correct, according to the [cited paper][1] a move takes $d$ stabilizer measurement rounds (for a distance $d$ surface

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Germund Johansson Nov 27 2025 08:27 UTC

It’s very helpful to see a careful re analysis of whether DESI DR2 really requires dynamical dark energy. A quick perspective from a framework where “Λ” actually has a controlled meaning.

In a recent series of notes I constructed a gauged constant‑vacuum (GCV) framework where the strictly spaceti

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Germund Johansson Nov 27 2025 08:25 UTC

These full shape DESI DR2 cosmological constraints are an important part of the current DE discussion. A quick perspective from a framework where “Λ” actually has a controlled meaning.

In a recent series of notes I constructed a gauged constant‑vacuum (GCV) framework where the strictly spacetime‑

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Germund Johansson Nov 27 2025 08:23 UTC

Thank you for this careful analysis of dynamical dark energy using DESI DR2 BAO. A quick perspective from a framework where “Λ” actually has a controlled meaning.

In a recent series of notes I constructed a gauged constant‑vacuum (GCV) framework where the strictly spacetime‑constant part of the m

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话小声 Nov 26 2025 10:08 UTC

想请教一下每个agent的具体的打分方式:如果用的自己训练的模型,是如何训练的呢
为什么agent增加之后有的指标掉的这么厉害呢;N-gram中的n是取多少呢,data_synthesizer是如何实现的呢,如何生成的呢,自动生成的么,
𝑅𝑠𝑡𝑒𝑝和Renhanced有啥区别么,有没有emb和rerank一起结合MARM进行对比评价的呢

zhenyu chen Nov 26 2025 02:36 UTC

Thank you very much for your thoughtful and detailed comment. Let me clarify our perspective and address your concerns point by point:

About the effective trainable region:
Our construction does not restrict all training dynamics to the shallow $O(\log n)$-depth region near the gadget layer. As sho

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Alex Meiburg Nov 25 2025 19:41 UTC

I have concerns about whether the proposed circuit construction actually addresses the problem. The idea of the construction can be described with an analog in classical machine learning:

Suppose I have a model M for, say, image generation. I create a new model M' which consists of the following:

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Carlo Marconi Nov 24 2025 07:05 UTC

Outstanding work!!

qodesign Nov 21 2025 17:14 UTC

interesting paper! did you find any examples that give a stabilizer or CSS code; preferably with d>2

Paul Webster Nov 21 2025 03:54 UTC

Thanks Tom!

Tom Scruby Nov 21 2025 03:47 UTC

welcome back

Q_cat_1729 Nov 15 2025 06:04 UTC

> You say that the values $r_j$ are random guesses, but this directly contradicts the paper. The paper doesn't say "choose $r_j$ randomly", it says: "The values $r_j$ are trial orders, typically a list of hypothesized orders (or their multiples/divisors) that the true order r may belong to."

Per

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Craig Gidney Nov 13 2025 19:22 UTC

I don't want to complain too harshly about doing examples, because having examples is a huge improvement over not having any. But... an example case in the tens of millions is really not large enough to be convincing here. To quote Scott Aaronson:

> We’ve had decades of experience to tell us that

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Q_cat_1729 Nov 13 2025 03:03 UTC

> The values rj are trial orders, typically a list of hypothesized orders (or their multiples/divisors) that the true order r may belong to.

> Basically you will need to know the entire factorization of the period for this to work, but if you knew that then you would already know the period and s

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Marcin Kotowski Nov 11 2025 21:25 UTC

And yet, despite this and many other retractions and BS papers "Nature" inexplicably continues to be treated as the pinnacle of scientific achievement...

Craig Gidney Nov 11 2025 19:55 UTC

I'm glad someone did the work of showing these representations should be safe. Solid stuff.

Tom Scruby Nov 10 2025 04:38 UTC

Thanks a lot for the reply! I'm looking forward to seeing what kind of codes you can obtain with these techniques.

Varun Menon Nov 10 2025 04:04 UTC

**An update on “Magic Tricycles: Efficient magic-state generation with finite block-length quantum LDPC codes”:**

We have made several major revisions to this work that are reflected in the current Arxiv version of the paper. In addition to correcting the technical issue with the original submissio

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stefan joka Nov 10 2025 02:16 UTC

Thank you both for your comments. I would like to see objections formulated more precisely: which part of the proof do You see as problematic? I am not sure that I understand what the comment "The N + 1 subspaces of operator space have nothing to do with the Hilbert space you start out with" really

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