David Sutter

@yaoyunshi @marcotomamichel @giulia_qp I am not an expert on these applications, but as far as I know there we are interested in statements involving the trace-distance which is related to the fidelity (via Fuchs-van der Graaf) and hence Uhlmann's theorem is relevant. Not sure how other relative entropies could help

@quantum_sutter @marcotomamichel @giulia_qp Among the many amazing implications of U’s are the impossibility of q bit commitment and in device-ind qcrypt a seed being globally uniform seed is equivalent to uniform-to-device, making composition security trivial. Any implications of your result on qcrypt or others?

Uhlmann's theorem states that the fidelity of two states rho and sigma can be expressed in terms of their purifications (where the fidelity simplifies). In arxiv.org/abs/2502.01749 we (with @giulia_qp and Renato Renner) generalize Uhlmann's theorem to Rényi relative entropies.

on bluesky now as `quantum-sutter`

@marcotomamichel congratulations Marco

I am very happy to share that I have been promoted to tenured full professor at NUS. It is a good time to reflect and thank all my mentors and collaborators over the last 15 years.

@_MonitSharma For cutting wires the situation is different. We have a provable separation between LO and LOCC (check out arxiv.org/abs/2302.03366).

@quantum_sutter Was just reading your previous paper on the same topic. The interesting findings you mentioned should come with a spoiler alert. Although it'll be interesting to know how classical simulation does not help in the recent paper.

We finally understand how to (optimally) cut arbitrary two-qubit gates. Two interesting findings: (1) cutting multiple gates jointly is always cheaper than cutting them individually (2) classical communication does not help ---> check out arxiv.org/abs/2312.11638

@_MonitSharma This work was 1.5 years before our recent paper arxiv.org/abs/2312.11638. At that time we had (and still have some) protocols for cutting gates with LOCC that we don't know how to cut with LO. But we don't have a proof that it is not possible (with the same overhead) with LO.

Follow up work on the effective dimension (with M. Datres, GP. Leonardi, @AFigalli): (i) stronger generalization bound (ii) lower bound that can be computed efficiently (for Markovian models) (iii) new simulation results --> check out arxiv.org/abs/2401.09184

There is something mesmerising about seeing one's paper(s) completely plagiarised, theorem by theorem, without any reference, and posted on arXiv. Compare arxiv.org/abs/2010.02152 with our arxiv.org/abs/1604.03023

Which of the two cuts below (dotted red vs dashed blue) is better? And what are the optimal costs? --> check out arxiv.org/abs/2302.03366

@RichardKueng @jenseisert @phfaist @sylvaingigan @sutter_tobias don't forget the famous Fawzi brothers (Omar, Hamza, and Allhussein)

@jenseisert @phfaist @sylvaingigan or even closer to 'home': David (@quantum_sutter) and Tobias (@sutter_tobias) Sutter.

#quiz « it runs in the family » can you find the longest dynasties of physicists ? (besides the Curie)

IBM blogpost about our recent work on circuit knitting research.ibm.com/blog/circuit-k…

Does classical communication between (small) quantum computers help to run large computations? We show it does. Check out arxiv.org/abs/2205.00016

In recognition of his contributions to mathematical physics, Jürg Fröhlich of @ETH_en is being inducted into the National Academy of Sciences. Watch the #NAS159 livestream: ow.ly/uuXh50IVNP2

How does entropy accumulate? Check out our recent generalization of the EAT arxiv.org/abs/2203.04989 [joint work with Tony, Omar, and Renato]

How hard is it to train a quantum support vector machine? --> check out arxiv.org/abs/2203.00031 (joint work with @GianGentinetta, Arne, and Stefan

New arXiv paper out! Purely classical machine learning :) in collaboration with @quantum_sutter @AFigalli and Stefan Woerner. We define and motivate a measure of capacity for ML models: the local effective dimension. We show how this quantity bounds generalization error 1/3

Happy to finally get this paper published and looking forward to seeing more results that bring error mitigation and correction together. @quantum_sutter journals.aps.org/prl/abstract/1…

I'm at #iccmp2021 today to receive the 2019 AHP prize awarded jointly with my co-authors Ralph Silva and @postquantum for arxiv.org/ct?url=https%3…. I wish they could be there. Nice to see @quantum_sutter (AHP prize 2018) and J. Bauch (AHP prize 2017) in person again!

@hubersebi @ETH_physics good job with the bike. I tried to run there yesterday and was struggling even without a bike :-(

Took some dedication to get to the office today @ETH_physics