Recent comments from SciRate

Marco Tomamichel Jun 24 2020 05:02 UTC

The paper has now been updated.

Sevag Gharibian Jun 23 2020 07:18 UTC

Thanks for the update! (It's good to see such forthcoming/virtuous academic integrity :-) ) Also good idea to post it here, will have to remember it in the future.

Abhinav Deshpande Jun 23 2020 05:54 UTC

Hi Henrik,

That certainly helps, thank you! I did read the other paper too.

Abhinav

Marco Tomamichel Jun 23 2020 02:42 UTC

The claim that we strengthen Matsumoto's result is incorrect. An update of the paper removing this claim is forthcoming.

Henrik Wilming Jun 22 2020 19:43 UTC

Hi Abhinav,

thank you for your comment! I believe that any $P$ fulfilling $\exp(\mathrm i P)=U$ decays as $1/|x-y|$. But indeed, we don't show this in the paper and should have phrased the appendix a bit differently. We will update it.
(I would like to thank Zoltán Zimborás for discussions regar

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Nicola Bernini Jun 21 2020 18:37 UTC

In short, the authors improved $\beta$ VAE Framework by reaching a better trade-off in terms of Reconstruction Quality vs Disentanglement (first contribution) according to a new metric they propose (second contribution)

The core idea comes from the fact the authors reached a deep understanding of t

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Abhinav Deshpande Jun 19 2020 19:41 UTC

Really nice paper! Regarding Appendix D, how can I see that there cannot be a different generator giving rise to the same dynamics at discrete times? I mean that $U = \exp(iP)$ does not have a unique solution for $P$, so it does not rule out a quasi-local generator for $U$. Or are you claiming that

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Yu Cai Jun 17 2020 20:29 UTC

Hi Filip, thank you for your interest. We are looking forward to making the code available once it is more user-friendly.

Blake Stacey Jun 16 2020 20:57 UTC

I'm going to cautiously advance the opposite of the italicized conjecture on p. 2 and hazard a guess that sets of $2d^2 - d$ equiangular lines will _not_ generally exist in $\mathbb{H}^d$. This inclination of mine is perhaps due to coming to the problem of equiangular lines from quantum theory, and

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Wojciech Kryszak Jun 16 2020 12:51 UTC

> the idea (emerging from the above assertion)
that the event A gives rise, as effect, to an event which is absolutely not different from A, has to be
rejected as an absurdity

It reminds me of John Wheeler's Participatory (aka Self-observing) Universe, and it seems you have unwillingly strength

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Filip Maciejewski Jun 15 2020 22:12 UTC

Exciting work! May I kindly ask if you thought about making your optimization code publicly available? I believe that it would make using your methods much easier for a lot of people!

Jerry Finkelstein Jun 15 2020 18:20 UTC

This is a clever and interesting paper. I am not a proponent of the "consciousness causes collapse hypothesis" (CCCH), but I nevertheless want to remark that somebody who is might attempt a defense of the CCCH along lines of the following:

Take the CCCH to say that wave-function collapse occurs w

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Zachary Remscrim Jun 09 2020 22:31 UTC

Cedric,

1) In Theorem 27, we show that if a promise problem is recognizable in O(log n) space and poly(n) time by a family of *general* quantum circuits, then it is also recognizable in O(log n) space and poly(n) time by a family of *unitary* quantum circuits. A bound on the hidden constants in t

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Cedric Lin Jun 09 2020 06:50 UTC

Great work! I haven't had time to gone through the paper in great detail, but I have two immediate questions:

1) You mention in the abstract that the procedure is simultaneously space-efficient and time-efficient, but I couldn't find a statement of this in the main body. Could you be more precise

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Robert Tucci Jun 07 2020 04:15 UTC

https://qbnets.wordpress.com/2020/06/07/anomaly-detection-with-quantum-computers-better-than-with-classical-computers/

Ravi Kunjwal Jun 05 2020 13:05 UTC

A short talk based on this work is scheduled today at 16:30 (UTC+2): https://www.youtube.com/watch?v=h4uFaV6rFSc

More details (including a 3-page abstract) here: https://www.monoidal.net/paris2020/talk/qs12t1.html

Ravi Kunjwal Jun 02 2020 16:04 UTC

Here's a short talk based on this, given today at QPL 2020: https://www.youtube.com/watch?v=uO08ci5dK6Q

Markus Heinrich May 28 2020 09:38 UTC

From my perspective, everything until Section 5 follows directly from the fact that the group $\mathrm{DS}(2^w)$ (aka *real Pauli group*) as well as the projective and normal Pauli group form unitary 1-designs and thus a tight frame for the space of complex matrices which gives you the desired Parse

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Mao LIN May 19 2020 05:11 UTC

It would be very interesting if one can show and realize the maximally localized Wannier functions in a digital quantum simulations.

Sevag Gharibian May 12 2020 08:52 UTC

Great work, please do keep it up! Minor gripe about abstract statement - the sentence about experimental systems is misleading, as far as I understand due primarily to the difficulty of reliable single-photon sources in the lab. I realize you say "in principle", but to the average CS person like mys

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Blake Stacey May 09 2020 23:15 UTC

The orthonormal operator bases defined in Eq. (9) were previously studied by Zhu, who proved that they saturate bounds defined using the negativity of quasi-probabilities [PRL **117** (2016), 120404, [arXiv:1604.06974\]][1].

[1]: https://scirate.com/arxiv/1604.06974

Ben May 05 2020 01:04 UTC

Simons Apers's talk at the Simons Institute: [https://simons.berkeley.edu/events/quantum-speedup-graph-sparsification-cut-approximation-and-laplacian-solving][1]

[1]: https://simons.berkeley.edu/events/quantum-speedup-graph-sparsification-cut-approximation-and-laplacian-solving

Robert Tucci May 01 2020 04:03 UTC

https://arxiv.org/abs/quant-ph/9805016
How to Compile a Quantum Bayesian Net

Seyed Sajjad Nezhadi Apr 24 2020 17:32 UTC

I am unsure about the reasoning presented in this paper. It seems to me that there is an issue with the reasoning used to upper-bound the query complexity of the multi-layer quantum search method.

On page 4, you begin by lower bounding the number of queries Q of the algorithm by a value Qmin (eq

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Varun Narasimhachar Apr 24 2020 03:52 UTC

Nice work. By the way, your paper's arxiv metadata abstract field has a redundant copy of part of the abstract.

Mankei Tsang Apr 23 2020 03:39 UTC

Proposition 7 for the SLD information is a known property called extended convexity; see S. Alipour and A. T. Rezakhani, PRA 91, 042104 (2015), http://dx.doi.org/10.1103/PhysRevA.91.042104. We proved it for multiple parameters by relating it to the strong concavity of the fidelity; see Ng et al., PR

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Richard Howl Apr 16 2020 07:07 UTC

Thanks very much for your comment Jerry. As with other table-top tests of quantum gravity, we are proposing an experiment in which all forces other than gravity, e.g. the electromagnetic force, can be neglected. Then, due to the universal coupling of gravity, gravity couples to the kinetic and mass

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Kianna Wan Apr 14 2020 23:36 UTC

much thanks to Craig Gidney, for pointing out that the only linear-depth Clifford component can equivalently be implemented in logarithmic depth

Ryan Babbush Apr 13 2020 17:57 UTC

Indeed, just focusing on T complexity is a bit too simplistic. I only quoted that number because your abstract focused on T complexity. The tradeoff between gate complexity and space complexity is why the abstract of [arXiv:1902.02134][1] emphasizes the reduction in surface code spacetime volume (a

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Sam Pallister Apr 13 2020 16:57 UTC

Hi Ryan,

I agree with your argument that the $10^{15}$ value is outdated at this point. I'll post an updated version that better reflects this. However, the $10^{11}$ figure is a swing too far in the opposite direction, I think. Even though the algorithm in [arXiv:1902.02134][1] is the most minimal

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Ryan Babbush Apr 13 2020 05:13 UTC

The $10^{15}$ figure in the abstract refers to an older algorithm. More recent work has brought estimates for FeMoco to around $10^{11}$ (see [arXiv:1902.02134][1]), albeit with some ancilla (but even a version with very few ancilla improves from $10^{15}$ gates). That new work is based on qubitizat

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Jerry Finkelstein Apr 09 2020 16:43 UTC

This is certainly an important result. However, it does seem to require the assumption that "the classical interaction would not induce quantum self-interaction". So I wonder how certain we can be that, for example, classical gravity might not induce a very small term (such as suggested in footno

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Cupjin Huang Apr 06 2020 18:36 UTC

The code implementing the angle finding algorithm, together with an example of Hamiltonian simulation, is available at [GitHub][1].

[1]: https://github.com/alibaba-edu/angle-sequence

Blake Stacey Apr 01 2020 19:33 UTC

I was sure that somebody had won an Ig Nobel for doing this, but I think my memory mixed up the levitating-frog experiment with a stunt that they did back in the day at the MIT Magnet Lab, lowering the temperature of a whole workshop with LN2 until they could Meissner a magnet off the floor.

Robin Blume-Kohout Apr 01 2020 13:12 UTC

After reading footnote [32], I would like to enthusiastically urge everyone to cite this paper heavily via every medium. My homestead on the Tozitna River in interior Alaska is, in fact, engaged in a long-running and ongoing war with beavers. The dam critters keep building dam after dam across the

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Māris Ozols Apr 01 2020 12:13 UTC

A breakthrough!

Mark M. Wilde Mar 17 2020 02:34 UTC

now this is one paper on QKD that I think deserves many scites! :)

Victory Omole Mar 11 2020 14:39 UTC

Tensorflow Quantum combines Tensorflow with [Cirq](https://github.com/quantumlib/Cirq). Are you asking for Cirq to be combined with pyTorch as well?

Andreas Wendt Mar 10 2020 02:44 UTC

Cool, thanks. Can now somebody please port it to pyTorch?

rrtucci Mar 09 2020 08:24 UTC

https://qbnets.wordpress.com/2020/03/09/google-releases-tensorflow-quantum/

甘文聪 Mar 08 2020 04:01 UTC

A quick question. Volume is complexity. Then the time that Alice needs to measure the volume is the complexity of complexity, just like

>Complexity of complexity is the number of simple logical steps that it would take to confirm
$\mathcal{C} \le \mathcal{C}_0$

Then why can we assume

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David Gross Mar 04 2020 07:39 UTC

Thanks, Edgar, Vishal, for your feedback!

The title is an attempt at humor - no sensationalism intended. I don't think that a technical paper on gate decompositions will be understood as taking a stance on the validity of mystic medicine. (In the same way that the title of Scott Aaronson's book i

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Christopher Chubb Mar 04 2020 02:30 UTC

I agree that scientists should suppress their tendency to *excessive* sensationalism, but I don't know that this title crosses the line. In fact, in this case, it seems to be a relatively apt description of the title and amusing to boot. It certainly caught my attention.

Perhaps a note somewhere

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Vishal Katariya Mar 03 2020 17:17 UTC

I agree.

Edgar A Aguilar Mar 03 2020 10:22 UTC

Perhaps it would be good to reconsider the title. As scientists, we should not succumb to the temptation for sensationalism - and we should try to mark a clearer distinction between real science and pseudoscience.
I think the work you did here is really impressive, and the title removes some of thi

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Jalex Stark Mar 02 2020 16:21 UTC

Takes a task that I thought required complicated self-testing techniques and achieves it with a beautifully simple protocol that requires almost no technology for the analysis. This should be taught in classes.

Steve Flammia Feb 24 2020 20:43 UTC

Regarding the name, I actually prefer "shadow estimation" for this task. (I suggested this as well to Scott, but he went with "shadow tomography" instead.) This is because tomography is the inverse problem of taking a shadow and reconstructing the object that produced the shadow. The term "shadow" d

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Hsin-Yuan Huang Feb 24 2020 19:28 UTC

Good observation! The main theoretical result we proved for predicting quadratic functions with random Pauli measurements is given in Example 1, Appendix (A3). The number of measurements needed to predict $M$ quadratic functions to $\epsilon$ additive error is $\mathcal{O}(\log(M) 4^k / \epsilon^2)$

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Alireza Seif Feb 24 2020 15:25 UTC

Congratulations on this very exciting work! I have a question regarding the second Rényi entropy measurements in Figure 4b. The error in Brydges et al. scales like $\frac{1}{\sqrt{\text{num. of exper.}}}$ as expected. However, the figure suggests that the shadow protocol's error scales as $\frac{1}{

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Mankei Tsang Feb 21 2020 05:52 UTC

I completely agree that the quantum problem has interesting new nuances and I look forward to reading your work as well as related papers; I'm just not sure about the necessity of the name "shadow tomography."

Regarding the issue of non-commuting observables, it is interesting to note that the Ho

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