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Florian Meier

@mathsmire.bsky.social

420 followers 140 following 32 posts

Foundational questions: Raclette or Fondue? 🧀🇨🇭 What is time without entropy? 🕒 || PhD student at quitphysics.info when not stuck hiking in nordic wilderness

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Reposted by Florian Meier

Nicolai Friis @improbabilitydrive.bsky.social · Aug 20

Glad someone took the time to debunk the (obviously nonsensical) claim that Bell inequalities could be violated w/o entanglement. It is astonishing (to say the least) that this claim was made by experienced authors & that it passed peer review in the first place, does not reflect well on the journal

Bell Inequality Violations Without Entanglement? It's Just Postselection

Recently Wang et al. have reported a violation of a Bell inequality without entanglement [arXiv:2507.07756]. We show that their result is an artifact of postselection. It is well known that postselect...

Reposted by Florian Meier

Henrik Wilming @arrr.de · Jul 23

A fun project with Seok Hyung, Jeongrak ( @perp-waterfall.bsky.social ), @nellynghy.bsky.social , and Paul Boes. We dusted off some old notes because there seemed to be renewed interest in what differentiates thermal operations from Gibbs-preserving maps.

arxiv.org/abs/2507.16637

Florian Meier @mathsmire.bsky.social · Jul 15

time-reversal with indefinite causal order

Florian Meier @mathsmire.bsky.social · Jul 10

sounds fishy 🐟

Reposted by Florian Meier

Henrik Wilming @arrr.de · Jun 23

Thanks to @phys.org.web.brid.gy for covering our recent work with @stotti-alex.bsky.social and @lvanluijk.bsky.social on embezzlement of entanglement in critical systems:

phys.org/news/2025-06...

Paper: www.nature.com/articles/s41...

Universal embezzlers naturally emerge in critical fermion systems, study finds

Embezzlement of entanglement is an exotic phenomenon in quantum information science, describing the possibility of extracting entanglement from a resource system without changing its quantum state. In...

Florian Meier @mathsmire.bsky.social · Jun 13

Congrats to Jake and all the collaborators for this fantastic work. They take the well studied problem of cooling quantum systems and use cool mathematics from group and graph theory to systematically characterize and solve that problem.

Jake Xuereb @curlyqubit.bsky.social · Jun 13

(1/n) Today on the arXiv, we examine the folklore that cooling a quantum system with access to another requires one to order their joint state eigenvalues in decreasing order and find that this sorting is actually dictated by a simple set of inequalities.

scirate.com/arxiv/2506.1...

Florian Meier @mathsmire.bsky.social · Jun 11

In that sense, I'd put thermo on a level above, a meta-theory.

Florian Meier @mathsmire.bsky.social · Jun 11

Good question! Well, I think it would indeed be more appropriate to put thermo on a different level of the hierarchy. Thermo is based on very general principles and those are usually fulfilled by microscopic theories which is why we see emergent thermodynamic phenomena in QTFs or also GR.

Florian Meier @mathsmire.bsky.social · Jun 2

Thanks and congrats of course too 😀 Will be a volume with exciting theory

Florian Meier @mathsmire.bsky.social · Jun 2

The beautiful artistic illustration in the first post is by Alexander Rommel (www.aerroscape.de), copyright by Alexander Rommel / TU Wien. I also thank my fantastic collaborators from @tuwien.at, @iqoqi-vienna.bsky.social, Chalmers and Malta from the @aspects-quantum.bsky.social consortium!

Florian Meier @mathsmire.bsky.social · Jun 2

What this project also shows in my opinion is how important it is to create an informal, inviting and friendly discussion culture in science where also junior people happily express their opinions and thoughts; and how such an environment can seed exciting scientific projects. go.nature.com/4jWxUm7

Florian Meier @mathsmire.bsky.social · Jun 2

Here, you can see an animation of the excitation travelling around a ring of 50 sites (y-axis = occupation probability, x-axis = where).

Florian Meier @mathsmire.bsky.social · Jun 2

For example with quantum clocks it is possible to circumvent such limitations. The ring-clock does this by counting cycles completed by a single quantum particle traveling a ring. Since coherent transport is dissipation-free, this clock breaks the linear entropy-precision bound exponentially.

Florian Meier @mathsmire.bsky.social · Jun 2

Generally, the more accurate a clock is, the more entropy it produces. For a wide range of classical stochastic clocks this is proved by the so-called "Thermodynamic Uncertainty Relation", which provides a linear relationship between clock precision and entropy.

Florian Meier @mathsmire.bsky.social · Jun 2

What started as informal discussions on the Danube beach in Vienna during QTD2023 has been published at last. Trying to come up with an experimentally feasible quantum clock we came across a rich model – the ring clock – that overturned a common wisdom in the community. doi.org/10.1038/s415...

Copyright by Alexander Rommel / TU Wien.

Florian Meier @mathsmire.bsky.social · May 12

Florian Meier @mathsmire.bsky.social · May 2

Fantastic, congrats!

Reposted by Florian Meier

ASPECTS @aspects-quantum.bsky.social · Apr 28

Don't forget to submit your abstract for our conference in Dublin, August 2025! www.aspects-quantum.com/flqt2025

FLQT 2025 — ASPECTS

Fundamental Limits of Quantum Technologies conference, Dublin, 25-29 August 2025

www.aspects-quantum.com

Reposted by Florian Meier

Mark Mitchison @mitchison.bsky.social · Apr 7

We are excited for Fundamental Limits of Quantum Technologies conference, Dublin, 25-29 August. Only three weeks left until the abstract submission deadline, don't delay! All details at www.aspects-quantum.com/flqt2025

Reposted by Florian Meier

Jake Xuereb @curlyqubit.bsky.social · Mar 31

Sms alot of people wanna go to Benasque QI than one can fit in the beautiful tiny village.

Having organised a bunch of stuff in Malta, I feel the urge to organise a straggler event on the island of Gozo.

If interested, fill this form so I can gauge interest - share!

forms.gle/azwrJe8AidrS...

Gozo QI - Expression of Interest

I really like no timetable free discussion workshops. It seems like the Benasque Quantum Information Workshop has gotten too many applicants to cater for the demand. Having organised a couple confer...

Reposted by Florian Meier

Mark Mitchison @mitchison.bsky.social · Mar 25

We’re organising a conference in Dublin! Fundamental Limits of Quantum Technologies 2025 — everything from error mitigation on NISQ devices, through control constraints on complex quantum systems, to quantum thermodynamics and energetics, and much more! Abstract submission and registration open! 👇

NAresgroup @naresgroup.bsky.social · Mar 25

🔥 Excited to announce 'Fundamental Limits of Quantum Technologies', a conference at The Alex Hotel, Dublin,
25–29 August 2025! 🌐 Abstracts & early-bird registration now open: www.aspects-quantum.com/flqt2025

Reposted by Florian Meier

Philip Taranto 🍋 @tarantophilip.bsky.social · Mar 14

Wrote up a little tutorial + review on higher-order quantum operations. If you love quantum channels, you can think of these as linear maps that act on channels themselves in manner fully consistent with quantum theory! I hope it helps future students / researchers! 🤗
arxiv.org/abs/2503.09693

Higher-Order Quantum Operations

An operational description of quantum phenomena concerns developing models that describe experimentally observed behaviour. $\textit{Higher-order quantum operations}\unicode{x2014}$quantum operations ...

Florian Meier @mathsmire.bsky.social · Feb 7

Congrats Shintaro!

Reposted by Florian Meier

Mark Mitchison @mitchison.bsky.social · Feb 4

Latest preprint from the ASPECTS consortium! arxiv.org/abs/2502.00096 Experiments by the amazing @naresgroup.bsky.social and theory by @mathsmire.bsky.social of @quitphysics.info We measured the entropy cost of generating and recording ticks in a microscopic clock
1/6 🧵👇

Depiction of the quantum-classical transition in a microscopic clock. A quantum clock transitions between three discrete states, driven by thermal noise. These transitions are amplified by a sensor into a classical signal, which can be shared among classical observers as an objective record of the passage of time.

Florian Meier @mathsmire.bsky.social · Jan 16

Wow, so beautiful. And very cool thesis cover!