This is for the wrong component of O(n) as you point out. You can play around a bit with the `real_csd` code in `linalg.py` to adjust to the negative-determinant branch. Otherwise, compiling atypical matrices is not quite covered by our techniques (yet). Happy to chat further about this!

flagsynth/flagsynth/ortho_synth.py at main · PennyLaneAI/flagsynth Unitary synthesis with the optimal number of rotation gates https://arxiv.org/abs/2603.20376 - PennyLaneAI/flagsynth

Ah I see! Yeah that sounds like more specialized tools will be needed.
In the meantime, I just added a new method to flagsynth, called `ortho_synth`. It synthesizes a SO matrix to PennyLane's multiplexed rotations `SelectPauliRot`, which you can then further decompose github.com/PennyLaneAI/...

some subgroup of SO(n)? Otherwise, SO(n) has dimension (n^2-n)/2 and that's the parameter count you'd get with the recursive CSD indicated above :) I hope this helps, happy to hear more thoughts you might have, and about your use case! Thanks :)

This decomposition of multiplexers also is parameter-optimal. I am not sure how much better we might be able to do in terms of CNOTs, the secondary cost metric in our work.
Regarding your hint at n^2 vs n parameters, why do you say that SO(n) matrices are determined by n parameters? Are you using

Hi nate!
The Cosine Sine Decomposition(CSD) works naturally with real matrices, and it automatically is parameter-optimal (unlike the complex-valued one, which forces us to do all the diagonal movement gymnastics). The multiplexed RY rotations can then be decomposed in the standard Mottonen way.

The idea is to decouple the journals from the review step. They’ll still exist, but they’ll need to add other value. They’ll highlight, curate, add new perspectives. If they do a good job they can still be prestigious (like Scientific American or Wired) (1.2) 👇

Quantum Computing and Early Fault-Tolerant Simulations at Los Alamos National Laboratory Los Alamos National Laboratory is Hiring! Search available jobs or submit your resume now by visiting this link. Please share with anyone you feel would be a great fit.

Our group is looking to hire postdocs to work at the intersection of quantum computing, quantum algorithms, quantum machine learning, simulation of many-body quantum systems and early-fault tolerant quantum computing

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Reposts appreciated!

When you realize the whole yearly budget for Quantum journal is equal to 8 Nature APCs - and they don't even wreck your paper in proof stage because...there is none

Last week, we published a paper that really excites me:
"Circuit compression for 2D quantum dynamics"

Using Pauli propagation, we (Matteo) were able to compress Trotter circuits for systems up to 30x30 with depth reductions of x2 to x13.

Link: arxiv.org/abs/2507.01883

Uploaded (replaced) a paper to arXiv today for the first time in a while.. and discovered some new features! 🤩

✅ You can choose your compiler (incl. pdflatex)
✅ You can select the top-level TeX file
✅ There is a new "Review Files" stages that detects which files are unused!

🥰 and more: ... 1/3

Not sure whether useful here but I recently learned about the Galois package, which was useful for my purpose! mhostetter.github.io/galois/latest/ it is quite nicely integrated with numpy.

Unitary synthesis with recursive KAK decompositions | PennyLane Demos Learn leading techniques for unitary synthesis, and how they all use KAK decompositions.

Thanks for the shout-out! If you liked this one, there are two follow-ups that might be interesting as well :)
Unifying unitary synthesis techniques based on Cartan decompositions: pennylane.ai/qml/demos/tu... and KAK-based compilation of Hamiltonian simulation: pennylane.ai/qml/demos/tu...

Characterizing quantum resourcefulness via group-Fourier decompositions In this work we present a general framework for studying the resourcefulness in pure states for quantum resource theories (QRTs) whose free operations arise from the unitary representation of a group....

🚨Excited to share our new paper "Characterizing quantum resourcefulness via group-Fourier decompositions" from last year's LANL Quantum Computing summer School📘 arxiv.org/abs/2506.19696 !

Open position at QuSoft / University of Amsterdam: Assistant Professor in Quantum Computing and Simulation for Quantum Chemistry and Materials
qusoft.org/qusoft-vacan...
Deadline: 14 July 2025

We have several open, fully-funded PhD and Postdoc positions at my group, now at the University of Tübingen. Please #RT and share with potential candidates!

Generally: AI for scientific discoveries in physics 🔥.
mariokrenn.wordpress.com/wp-content/u...

What I gather from the most recent DWAVE saga. TLDR: I don't think the spoofers have a done a very good or convincing job here 🤷

QIP 2026 is in Riga. Dates for QIP 2027 are preliminary

Job Opportunities at CQSL At the Computational Quantum Science Lab we typically have several openings yearly (at the PhD/ Postdoc level). Applications are reviewed twice a year, at the beginning of April and at the beginning o...

Looking for a talented postdoc to join my group (the Computational Quantum Science Lab) at EPFL, in Lausanne 🇨🇭

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Scaling and networking a modular photonic quantum computer - Nature A proof-of-principle study reports a complete photonic quantum computer architecture that can, once appropriate component performance is achieved, deliver a universal and fault-tolerant quantum…

Scaling and networking a modular photonic quantum computer from @Xanadu in @Nature (Open Access paper)

PhD opening at QuantumFutur Junior Research group, hosted by the Helmholtz-Zentrum Dresden-Rossendorf lead by Werner Dobrautz @dobrautz.bsky.social

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Postdoc opening in Quantum Computing for Quantum Chemistry at QuantumFutur Junior Research group, hosted by the Helmholtz-Zentrum Dresden-Rossendorf lead by Werner Dobrautz @dobrautz.bsky.social

#QuantumComputing #QuantumSimulation #QuantumChemistry

www.quantiki.org/position/pos...

If the dynamical Lie algebra of the Hamiltonian is small enough, this gives you a useful time evolution circuit with time-independent(!) depth. Pretty nice 😎 If you like quantum complexity theory more than Lie theory, this is fast forwarding a Hamiltonian in practice 🙂

Fixed depth Hamiltonian simulation via Cartan decomposition | PennyLane Demos Using Cartan decomposition and the KAK theorem to decompose unitary gates following the approach in the paper Fixed Depth Hamiltonian Simulation via Cartan Decomposition (arXiv2104.00728) with a code ...

Check out this very nice demo by @qottmann.bsky.social on a constructive compilation routine for Hamiltonian simulation by Kökcü et al.
This is the Cartan, or KAK, decomposition in practice :)

Demo: pennylane.ai/qml/demos/tu...
Original work: journals.aps.org/prl/abstract...

Seeing our software and resources be used by other researchers and practitioners in the qc space gives me extreme "academic pride", for a lack of better words 🥲

Here's to more well-documented code in 2025

Myths around quantum computation before full fault tolerance: What no-go theorems rule out and what they don't In this perspective article, we revisit and critically evaluate prevailing viewpoints on the capabilities and limitations of near-term quantum computing and its potential transition toward fully fault...

To reach some consensus about the prospects of near-term (late nisq and early fault tolerant) quantum computing, we had a 3-day discussion event (“Quantum Now”) in Lapland with both optimists and pessimists. This continued at SeeQA 2024 in Oxford. See our conclusions here arxiv.org/abs/2501.05694

Google unveils ‘mindboggling’ quantum computing chip Chip takes minutes to complete tasks that would otherwise take 10,000,000,000,000,000,000,000,000 years

In case you're a science & technology journalist, here's our guide on how NOT to write a news article about Google's new "mindboggling" quantum computing chip.
www.theguardian.com/technology/2...

🚨Applications for LANL's 2025 Quantum Computing Summer School are open!

Please apply here
👇
lanl-summer-school-programs.wizehive.app/program/quan...

Reposts appreciated!

Hey #Quantumsky 👋🏾

This is an attempt at indexing the growing quantum community here on Bluesky. Please let me know if you'd like to be added to the list.

Genuinely happy to see what looks like a successful migration from the birdsite 😄

go.bsky.app/VHXg1yi