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QuOI Theory

@quoi-theory.at
285 followers 179 following 151 posts

We're Quantum Optics & Information: the theory division of TU Wien's Atominstitut. Also with groups for quantum thermo, foundations, computing, and more! We ❤️ open, diverse science + good coffee! Find us at quoi-theory.at Posts by @tomrivlin.com

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Alex @itsmealeale.bsky.social · 8h
Can a physically motivated symmetry make many-body magic analytically solvable? If so, at what cost? We answer this question (arxiv.org/abs/2609.38319), by looking at pairwise parity symmetry. This gives rise to a family of quantum states known as X-states. (continue..)/n
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Florian Meier @mathsmire.bsky.social · 28/08/2026
How does memory help to count? Using n bits, one can count perfectly up to 2^n. Higher numbers can only be counted on average, with an uncertainty growing with the number to be counted. We looked at how this uncertainty can be reduced when using qubits instead: arxiv.org/abs/2608.26240
Two tick distributions, on the left perfectly sharp and on the right broadly distributed around the mean.
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Jake Xuereb @curlyqubit.bsky.social · 25/08/2026
Today on the arXiv with @itsmealeale.bsky.social we provide insights into the question of whether the presence of quantum entanglement at equilibrium can influence how an interacting system responds to changes in temperature. scirate.com/arxiv/2608.2...
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QuOI Theory @quoi-theory.at · 21/08/2026
New from Klára. With superactivation of genuinely multipartite entanglement, how much extra entanglement can you get from local projections of multiple copies of a state? Here it's shown that an optimal number can exist arxiv.org/abs/2608.19427
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QuOI Theory @quoi-theory.at · 17/08/2026
New preprint from Phila, teaming up with a group of experimentalists to design and test a new adaptive scheme for accurately reconstructing bosonic states (in particular Wigner functions) using fewer measurements arxiv.org/abs/2608.02049
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QuOI Theory @quoi-theory.at · 17/08/2026
New from Simon (can you tell admin recently came back from holiday and is catching up? 😅) Here we have a preprint showing how to apply the framework of quantum hypothesis testing to the sequential (continuous) parameter regime arxiv.org/abs/2608.01248
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QuOI Theory @quoi-theory.at · 17/08/2026
New preprint from Manu. They show the circumstances under which the quantum jump formalism is valid and effective when the dissipators in the quantum master equation are non-additive, finding that imperfect jumps can make additive unravellings possible arxiv.org/abs/2608.14469
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QuOI Theory @quoi-theory.at · 17/08/2026
New preprint from Shuheng, showing how indefinite causal order can be used to extend the parameter range over which entanglement remains certifiable after being transmitted through a noisy channel arxiv.org/abs/2608.14110
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Tom Rivlin @tomrivlin.com · 17/08/2026
New preprint! Continuing on our work of describing quantum measurements as a dynamical, unitary process, here we apply these principles to numerical simulations of a more realistic many-body system -- a lattice of hopping particles arxiv.org/abs/2608.11319
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QuOI Theory @quoi-theory.at · 03/08/2026
New from Philipp in PRA, showing how to perform high-harmonic generation in the classically forbidden region, and produce super-Poissonian photon statistics in so doing. This allows them to test quantum properties of the driving field journals.aps.org/pra/abstract...
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QuOI Theory @quoi-theory.at · 31/07/2026
In our group we love the Landauer bound on dissipation. So in this new preprint from Jan, Jake, Pharnam, and Marcus, they explore how the cost of erasure can increase when one has access only to finite resources, in both the classical and quantum cases arxiv.org/abs/2607.27341
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QuOI Theory @quoi-theory.at · 24/07/2026
New preprint from Dani, Marcus, and Alberto: Working out how much work quantum systems do is hard work! In this new work, the team work up the courage to work through a new definition of the quantum work operator arxiv.org/abs/2607.20602
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QuOI Theory @quoi-theory.at · 24/07/2026
This first one is now out in PRL! journals.aps.org/prl/abstract...
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QuOI Theory @quoi-theory.at · 20/07/2026
New preprint! Erik, Pharnam, Moha & co. They look at quantum thermometry when the dynamics are non-Markovian, deriving expressions for the Fisher information and the scaling of the precision in this scenario arxiv.org/abs/2607.15978
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QuOI Theory @quoi-theory.at · 15/07/2026
New in Reports on Progress in Physics by Florian, Marcus, Pauli, and Jake: they develop a self-contained model of a quantum processor without external control, to figure out what thermodynamic resources a quantum computer fundamentally needs to operate iopscience.iop.org/article/10.1...
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QuOI Theory @quoi-theory.at · 02/07/2026
New in Sciences Advances from Nicky, Florian, Pauli, and Marcus: A new way to characterise high-dimensional, time-frequency entanglement in photons for use in quantum key distribution, all with methods that can use commercial telecom components! www.science.org/doi/10.1126/...
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QuOI Theory @quoi-theory.at · 02/07/2026
This is now out in PRX Quantum! journals.aps.org/prxquantum/a...
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QuOI Theory @quoi-theory.at · 30/06/2026
New preprint! Dorian and colleagues make a simple derivation of Wigner's Inequality and a basic quantum optical lab setup to test it, with data to go with it. If you're designing an undergrad program to teach QM and give students an intuition for it, this one's for you! arxiv.org/abs/2606.30255
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QuOI Theory @quoi-theory.at · 24/06/2026
New preprint! Philipp studies the implications of two-electron effects on the strong-field approximation and look at high-harmonic generation in this context arxiv.org/abs/2606.24765
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QuOI Theory @quoi-theory.at · 24/06/2026
New preprint! Shuheng looks at the implications for multipartite entanglement in many-body systems of exceptional points arxiv.org/abs/2606.24205
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QuOI Theory @quoi-theory.at · 24/06/2026
New preprint! Florian and Marcus propose a new, easily-implementable method for certifying entanglement in discrete time bin temporal superposition states arxiv.org/abs/2606.23817
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QuOI Theory @quoi-theory.at · 23/06/2026
New preprint! Philipp and colleagues show that bright-squeezed-vacuum-driven high-harmonic generation can lead to non-Gaussianity in the resulting states, or to Gaussian entanglement, or to non-classical Gaussian states arxiv.org/abs/2606.22714
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QuOI Theory @quoi-theory.at · 23/06/2026
New preprint! It's known that measurement error can make certifying quantum effects harder. But here, Simon and colleagues show that it's sometimes possible for an adversary to trick you into seeing entanglement using arbitrarily small errors! arxiv.org/abs/2606.20396
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Nicolai Friis @improbabilitydrive.bsky.social · 18/06/2026
What a brilliant day, three consecutive defenses: It was an honor to serve on the PhD committee of Philipp Sohr (middle), and then very proud to see my student Nicky Kai Hong Li (second from right) defend valiantly, before leaning back as Marcus' (left) student Iraj (second from left) took the stage
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QuOI Theory @quoi-theory.at · 17/06/2026
What's better than celebrating a PhD defence? How about THREE? Congrats to Drs (L-R) Umesh, Sohr, and Li for finishing their doctorates (and organising a three-in-a-row defence day!)
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Dulwich Quantum Computing @dulwichquantum.bsky.social · 03/06/2026
My mom: What have you been doing all these years? Me:
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Jake Xuereb @curlyqubit.bsky.social · 04/06/2026
@quoi-theory.at mods posted the defense pic where I look most dead - whilst I was tired, I was also very happy ❤️
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QuOI Theory @quoi-theory.at · 03/06/2026
New from Philipp: a Rep. Prog. Phys. about attosecond quantum optical interferometry! iopscience.iop.org/article/10.1... See also this write-up in Physics World: physicsworld.com/a/attosecond...
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QuOI Theory @quoi-theory.at · 03/06/2026
Congratulations, Dr. Xuereb! 🔥🧊🖥️👹
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QuOI Theory @quoi-theory.at · 28/05/2026
New preprint from Klára and Nico on genuinely multipartite entanglement: they show that all members of a certain kind of Gaussian state are both fully inseparable biseparable, and also GME. This raises the question: are ALL fully inseparable Gaussian states GME? arxiv.org/abs/2605.28404
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QuOI Theory @quoi-theory.at · 27/05/2026
New preprint! Here, Dorian, Marcus, and Eliza describe how to create a form of entanglement that has both discrete and continuous features in a quantum optical setting arxiv.org/abs/2605.26962
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QuOI Theory @quoi-theory.at · 22/05/2026
Well done, Phila and Tom!
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QuOI Theory @quoi-theory.at · 19/05/2026
Two new preprints today! First, a first arXiv posting for Bita. The team used a quantum optics setup to detect contextuality with sequential, single-photon measurements, both theoretically and experimentally arxiv.org/abs/2605.18112
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QuOI Theory @quoi-theory.at · 18/05/2026
This has now been published in PRA! journals.aps.org/pra/abstract...
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QuOI Theory @quoi-theory.at · 13/05/2026
New preprint! Dimpi, Shuheng, Giuseppe, and Konrad study the structure of covariance matrices for finite-dimensional position and momentum observables, expanding uncertainty relations to account for more complicated correlation structures arxiv.org/abs/2605.11876
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QuOI Theory @quoi-theory.at · 08/05/2026
Congratulations, Dr. Meier!
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QuOI Theory @quoi-theory.at · 29/04/2026
This is now out in PRE! journals.aps.org/pre/abstract...
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QuOI Theory @quoi-theory.at · 21/04/2026
This is now out in Quantum! quantum-journal.org/papers/q-202...
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QuOI Theory @quoi-theory.at · 21/04/2026
This is now published in PRL! journals.aps.org/prl/abstract...
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QuOI Theory @quoi-theory.at · 17/04/2026
New preprint! Carlos looks at the dynamics of an all-to-all quantum Ising model and finds that it expresses a wide range of behaviours, from integrable to chaotic arxiv.org/abs/2604.14798
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QuOI Theory @quoi-theory.at · 13/04/2026
New in PRA! Using analytic and numerical methods, Carlos and colleagues study how imperfections in a measuring device impact one's ability to characterise a quantum many-body state journals.aps.org/pra/abstract...
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QuOI Theory @quoi-theory.at · 09/04/2026
New preprint! Marcus and Nico from our team were involved in this huge roadmap on high-dimensional quantum photonics! arxiv.org/abs/2604.06528
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QuOI Theory @quoi-theory.at · 02/04/2026
...okay back to serious papers, starting with the field of many-body physics. In this new preprint, Julia, Nicky, Pharnam, and Giuseppe provide new optimal entanglement witnesses for various many-body thermal settings: arxiv.org/abs/2604.01157
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QuOI Theory @quoi-theory.at · 01/04/2026
A new, very serious preprint is out from Veronika and Alberto. No, don't look at today's date it's 100% legit we promise. It's a genuine proof that P=NP... (...if you believe in quantum many-worlds and are willing to destroy almost every observer in the multiverse 👀) arxiv.org/abs/2603.28869
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QuOI Theory @quoi-theory.at · 31/03/2026
This is now fully published in Reviews of Modern Physics. Congrats to all involved! journals.aps.org/rmp/abstract...
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QuOI Theory @quoi-theory.at · 31/03/2026
New preprint! Manu, Max, and Pharnam look at how long chaotic many-body systems take to equilibrate, with both analytics and a numerical model. They find both results that confirm random matrix theory and results that suggest it is lacking in places! arxiv.org/abs/2603.28587
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QuOI Theory @quoi-theory.at · 26/03/2026
New preprint! Philipp and colleagues show how quantum fluctuations can lead to symmetry-breaking and violation of classical selection rules in high harmonic generation, leading to squeezing-like behaviour arxiv.org/abs/2603.24377
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QuOI Theory @quoi-theory.at · 23/03/2026
New in Quantum! Shuheng and colleagues lay out new, experimentally-accessible ways to detect entanglement directly from measurements of the Wigner function! quantum-journal.org/papers/q-202...
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QuOI Theory @quoi-theory.at · 23/03/2026
We talk a lot here about weird quantum things, from conceptual foundations questions to technological challenges. It's easy to be confused by it all, so here's Phila from our group giving a TEDx Talk at TU Wien last year on demystifying quantum physics! www.youtube.com/watch?v=pJkO...
youtube.com
Demystifying quantum physics | Phila Rembold | TEDxTUWien
YouTube video by TEDx Talks
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QuOI Theory @quoi-theory.at · 20/03/2026
This is now fully published in Phys Rev Letters! journals.aps.org/prl/abstract...
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