Joschka Roffe

Hardware-tailored logical Clifford circuits for stabilizer codes

scirate.com/arxiv/2505.2...

This first first author paper of Eric appeared yesterday, but was not picked up by Scirate. It suggests novel strategies for implementing logical Cliffords of stabilizer codes under hardware constraints.

Hardware-tailored logical Clifford circuits for stabilizer codes

arxiv.org/abs/2505.20261

It is important to identify strategies for implementing Clifford unitaries at the logical level of stabilizer codes in #quantumerrorcorrection, respecting hardware constraints. Here is one such strategy.

📣 New pre-print on the arXiv today on generalisation of surface code lattice surgery to arbitrary CSS codes w/ Clément Poirson and Robert Booth. Congrats to @clemenson7.bsky.social on his first paper! 🎉

Thanks you!

The group's research include:

- Investigating new QEC protocols.
- Designing QEC decoding algorithms for specialised hardware.
- Logical gates for fault-tolerant logic.
- Design and implementation of QEC experiments,
- Developing open-source QEC software.

More details soon!

My group will tackle both the theoretical and practical challenges of building fault-tolerant quantum computers.

I'll be advertising postdoctoral research positions soon. Please get in touch if you're interested in joining or collaborating.

A banner showing a photo of Joschka Roffe. The following text is superimposed on the photo: "Joschka Roffe awarded EPSRC Quantum Technology Career Acceleration Fellowship". The University of Edinburgh School of Informatics logo and the UKRI EPSRC logo are also included in the banner.

Happy World Quantum Day! I'm excited to announce that I will be starting a new group dedicated to quantum error correction (QEC) at The University of Edinburgh Quantum Software Lab, funded by an EPSRC Quantum Technology Career Acceleration Fellowship!

Computing Efficiently in QLDPC Codes It is the prevailing belief that quantum error correcting techniques will be required to build a utility-scale quantum computer able to perform computations that are out of reach of classical computer...

📣 New paper: Computing Efficiently in QLDPC Codes w/ @TeamPhotonic! Lots of great stuff here:

- New subsystem codes w/ transversal gates that efficiently compile full Clifford Group.
- Single-shot decoding
- Huge circuit-level logic sims

scirate.com/arxiv/2502.0...

🚨Reminder: The deadline to apply for the Quantum Informatics CDT is tomorrow (15th Jan). Apply below 👇

www.quantuminformatics-cdt.ac.uk

Submissions for QEC 2025 are now open through March 28.

This will easily be the most exciting conference on quantum error correction yet!

Conference homepage:
qec25.yalepages.org

EasyChair submission page:
easychair.org/my/conferenc...

@physicssteve.bsky.social's Inside Quantum Podcast has two seasons and over 20 episodes in total. Highly recommended insidequantum.org

Yes. They are two separate programmes. You can apply for both.

Ah wow. This is amazing! Is it in a Github repo so we can contribute?

I'll see if the repo can be moved to the Quantum-journal GitHub organisation. Arxiv PDF upload would work. You could also upload the typst source alongside that, so the experience wouldn't be much different than with LaTeX

GitHub - quantumgizmos/quantum-journal-typst-template Contribute to quantumgizmos/quantum-journal-typst-template development by creating an account on GitHub.

Okay. I made a start. Basic functionality:

github.com/quantumgizmo...

Submissions for QCTiP 2025 are now open.

Yes that's the idea!

Anyone want to collaborate on making a @typst.app template for @quantum-journal.org?

PhD studentship in Quantum Error Correction Deadline: 31 January 2025 (or until the position is filled)

🎓 PhD in Quantum Error Correction

Applications are open for a 4-year collaborative PhD between @edinburghuni.bsky.social and the NQCC.

Project: designing QEC protocols and decoders for the NQCC's neutral atom quantum computing systems.

Apply by Jan 31 👇

informatics.ed.ac.uk/study-with-u...

It's the future! It's a shame the @arxiv-quant-ph.bsky.social doesn't support it yet.

Great. Sign me up! roffe.eu

I agree. Error worsening codes are codes too!

This image shows a threshold plot. The breakeven line is superimposed. I am explaining the difference.

Remember: the surface code threshold is not the breakeven point (for finite-size codes).

Image displays two representations of a QEC protocol. The first uses the traditional circuit notation and the second a Tanner graph notation similar to that used for classical LDPC codes.

PSA: The Tanner graph representation is the best way of depicting surface codes.

The circuit for the [[9,1,3]] Shor code. This QEC protocol is constructed by concatenating the 3-qubit phase-flip repetition code with the 3-qubit bit-flip repetition code.

I've enjoyed teaching students at Edinburgh University about QEC this term. Here I am introducing the famous [[9,1,3]] Shor code.

The CDT is spread across five universities: Edinburgh, Heriot Watt, Strathclyde, UCL and Oxford. The first training year will be spent at Edinburgh, and then you will have the option to pursue PhD projects at any of the five universities.

👋Always happy to discuss QLDPC codes.

📢PhD Positions in Quantum Computing
Applications are now open for the new CDT in Quantum Informatics. We are recruiting 16 students to start Sept 2025. Positions are fully funded for 4 years. Apply now:
quantuminformatics-cdt.ac.uk

Is this specific to leakage errors or a more general soft-input decoder in hardware? E.g., could you feed it soft info from BP pre-decoder?

Hello World!