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Joschka Roffe

@qec.codes
546 followers 585 following 53 posts

Quantum Error Correction | Quantum Software Lab | University of Edinburgh Homepage: roffe.eu

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Joschka Roffe @qec.codes · 19/06/2026
📢 New paper. 𝗡𝗲𝗮𝗿𝗲𝘀𝘁-𝗻𝗲𝗶𝗴𝗵𝗯𝗼𝘂𝗿 𝗴𝗮𝘁𝗲𝘀 𝗮𝗿𝗲 𝗮𝗹𝗹 𝘆𝗼𝘂 𝗻𝗲𝗲𝗱: 𝗛𝗶𝗴𝗵-𝗿𝗮𝘁𝗲 𝗾𝘂𝗮𝗻𝘁𝘂𝗺 𝗹𝗼𝘄-𝗱𝗲𝗻𝘀𝗶𝘁𝘆 𝗽𝗮𝗿𝗶𝘁𝘆-𝗰𝗵𝗲𝗰𝗸 𝗰𝗼𝗱𝗲𝘀 𝗼𝗻 𝗮 𝗽𝗹𝗮𝗻𝗮𝗿 𝗴𝗿𝗶𝗱. scirate.com/arxiv/2606.1... 𝘁𝗹𝗱𝗿; For several years now, we have been advocating for qLDPC codes as a resource-efficient alternative to the surface code. 1/3
scirate.com
Nearest-neighbour gates are all you need: High-rate quantum low-density parity-check codes on a planar grid
High-performance quantum low-density parity-check codes promise substantial reductions in the overhead of fault-tolerant quantum computation, but most constructions require long-range connectivity or ...
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Joschka Roffe @qec.codes · 08/06/2026
Back in Santa Barbara this week for #QEC2026. Looking forward to meeting colleagues, old and new, and hearing about the latest and greatest in QEC!
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Joschka Roffe @qec.codes · 01/06/2026
🚨Registration deadline today! TartanQEC Workshop 24-26 June. Poster submissions remain open until end-of-day (AOE). Sign up now 👇 qec.codes/tartan2026
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Joschka Roffe @qec.codes · 20/05/2026
TartanQEC Workshop | University of Edinburgh 24-26 June. The full programme is now available. Poster submissions are still being accepted & registration deadline is 1st June. Sign up now 👇 qec.codes/tartan2026/t...
qec.codes
TartanQEC Timetable
TartanQEC Workshop timetable, 24-26 June 2026, School of Informatics, University of Edinburgh.
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Joschka Roffe @qec.codes · 08/05/2026
🚨TartanQEC Workshop. Final day to submit a talk abstract 👇 qec.codes/tartan2026/
qec.codes
TartanQEC Workshop
TartanQEC Workshop, 24-26 June 2026, School of Informatics, University of Edinburgh.
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Joschka Roffe @qec.codes · 07/05/2026
📢 TartanQEC Workshop. The deadline for abstract submission is tomorrow. Submit your best work now 👇 qec.codes/tartan2026
qec.codes
TartanQEC Workshop
TartanQEC Workshop, 24-26 June 2026, School of Informatics, University of Edinburgh.
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Joschka Roffe @qec.codes · 29/04/2026
📢 TartanQEC Workshop, 24-26 June, University of Edinburgh. Along with @jdpritchard.bsky.social, I am organising an event on practical methods for quantum error correction. See details and submit your best work for poster/talk before 8th May 👇 qec.codes/tartan2026/
qec.codes
TartanQEC Workshop
TartanQEC Workshop, 24-26 June 2026, School of Informatics, University of Edinburgh.
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Jonathan Pritchard @jdpritchard.bsky.social · 29/04/2026
Interested in qauntum error correction? Join @qec.codes and I at the TartanQEC conference in Edinburgh 24-26 June 26 as part of the Quantum Fringe. Abstract submission open until 8th May - for details and registration see qec.codes/tartan2026/
qec.codes
TartanQEC Workshop
TartanQEC Workshop, 24-26 June 2026, School of Informatics, University of Edinburgh.
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Joschka Roffe @qec.codes · 06/03/2026
📢 New paper. 𝐐𝐆𝐏𝐔: 𝐏𝐚𝐫𝐚𝐥𝐥𝐞𝐥 𝐥𝐨𝐠𝐢𝐜 𝐢𝐧 𝐪𝐮𝐚𝐧𝐭𝐮𝐦 𝐋𝐃𝐏𝐂 𝐜𝐨𝐝𝐞𝐬. A great collaboration w/ Boren Gu, Andi Lui, Armanda Quintavalle, Xian Xu, & @jenseisert.bsky.social 𝐭𝐥𝐝𝐫; Quantum LDPC codes are an exciting architecture for fault-tolerant ... 1/n scirate.com/arxiv/2603.0...
scirate.com
QGPU: Parallel logic in quantum LDPC codes
Quantum error correction is critical to the design and manufacture of scalable quantum computing systems. Recently, there has been growing interest in quantum low-density parity-check codes as a resou...
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Joschka Roffe @qec.codes · 04/02/2026
Great day back in Durham visiting @durhamqlm.bsky.social to give a seminar on QEC and our recent work at Quantum Software Lab. Also fun to discuss the fault-tolerance of the Welsh towname Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch w/ @ifanghughes.bsky.social @tobifranzen.bsky.social
Opening slide of my presentation on Quantum Error Correction at Durham Uninversity. Slide features a picture of the Durham student union and Kingsgate bridge, famously designed by legendary North Eastern arcitect Ove Arup and considered to be one of the world's finest examples of brutalist architecture.A slide from my presentation comparing surface codes to QLDPC codes. Background: surface codes are a leading approach to QEC, favoured for their local connectivity and straightforward ability to scale to arbitrary distance. However, from a coding theory perspective, they are far from optimal codes, owing to the fact that only a single logical qubit is encoded per patch. In practice, it is estimated that ~1000 qubits will be required per logical qubit in a surface code architecture, making them much less efficient than classical LDPC codes (of the type used in 5G and WiFi) where encoding ratios can be as low as 2-to-1. Quantum LDPC are modelled on classical codes, and it is has been shown (through simulation) that they code achieve encoding densities as low as 50-to-1 (some 20x improvement than surface codes). The tradeoff is that QLDPC codes are much less structured than surface codes, requiring long-range interactions between qubits. The QLDPC Tanner graph shown on the slide depicts a naive layout that I usefully refer to as the "spaghetti connectivity".Language is redundant by design. The town of Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch in Anglesey Wales is probably the best error corrected placename in the world!
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Timo Hillmann @timohillmann.bsky.social · 03/09/2025
Working on LSD was fun! - Our paper on Localized statistics decoding (LSD) for qLDPC codes is now in print. LSD is a highly parallelizable, reliability-guided inversion decoder that exploits the clustering of errors. Think of it as a parallel version of OSD. www.nature.com/articles/s41...
nature.com
Localized statistics decoding for quantum low-density parity-check codes - Nature Communications
Quantum low-density parity-check (QLDPC) codes offer lower overhead than topological quantum error-correcting codes, but decoding remains a key challenge for scalable fault-tolerant quantum computing....
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Joschka Roffe @qec.codes · 03/09/2025
📢 Our paper, 𝗟𝗼𝗰𝗮𝗹𝗶𝘀𝗲𝗱 𝘀𝘁𝗮𝘁𝗶𝘀𝘁𝗶𝗰𝘀 𝗱𝗲𝗰𝗼𝗱𝗶𝗻𝗴 𝗳𝗼𝗿 𝗾𝘂𝗮𝗻𝘁𝘂𝗺 𝗹𝗼𝘄-𝗱𝗲𝗻𝘀𝗶𝘁𝘆 𝗽𝗮𝗿𝗶𝘁𝘆-𝗰𝗵𝗲𝗰𝗸 𝗰𝗼𝗱𝗲𝘀, is now published in Nature Communications (Nature Portfolio). Great to see it in print! www.nature.com/articles/s41...
nature.com
Localized statistics decoding for quantum low-density parity-check codes - Nature Communications
Quantum low-density parity-check (QLDPC) codes offer lower overhead than topological quantum error-correcting codes, but decoding remains a key challenge for scalable fault-tolerant quantum computing....
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Joschka Roffe @qec.codes · 23/08/2025
Your wish will be fufilled: this will be in arXiv V2 👀
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Alexis Morvan @amorvan.bsky.social · 23/08/2025
Color code decoding with some big claim: arxiv.org/abs/2508.15743 I wish they could try to benchmark this decoder against the experimental color code data from arxiv.org/pdf/2412.14256 zenodo.org/records/1423... We are releasing experimental data so people can try out their decoding algorithms!
arxiv.org
Colour Codes Reach Surface Code Performance using Vibe Decoding
Two-dimensional quantum colour codes hold significant promise for quantum error correction, offering advantages such as planar connectivity and low overhead logical gates. Despite their theoretical ap...
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John Preskill @preskill.bsky.social · 17/08/2025
The QEC25 conference hosted by @yaleqi.bsky.social was really excellent, and videos of all talks are available. So much recent progress on quantum error correction! qec25.yalepages.org
qec25.yalepages.org
QEC25
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Joschka Roffe @qec.codes · 12/08/2025
James Mills introducing Logical Accreditation to #QEC2025 at @yaleqi.bsky.social See our recent preprint here: arxiv.org/abs/2508.05523
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Josu Etxezarreta Martinez @katutxakur.bsky.social · 06/08/2025
Check out the V2 of our qLDPC decoding paper "An almost-linear time decoding algorithm for quantum LDPC codes under circuit-level noise". The meme summarizes our approach. @qec.codes
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Jens Eisert @jenseisert.bsky.social · 28/05/2025
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.
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Jens Eisert @jenseisert.bsky.social · 27/05/2025
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.
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Joschka Roffe @qec.codes · 05/05/2025
📣 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! 🎉
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Joschka Roffe @qec.codes · 14/04/2025
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!
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.
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Joschka Roffe @qec.codes · 12/02/2025
📣 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...
scirate.com
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...
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Joschka Roffe @qec.codes · 14/01/2025
🚨Reminder: The deadline to apply for the Quantum Informatics CDT is tomorrow (15th Jan). Apply below 👇 www.quantuminformatics-cdt.ac.uk
quantuminformatics-cdt.ac.uk
QI CDT – EPSRC Centre for Doctoral Training in Quantum Informatics
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Steve Flammia @sflammia.bsky.social · 11/01/2025
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...
qec25.yalepages.org
QEC25
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qctip2025.bsky.social @qctip2025.bsky.social · 05/12/2024
Submissions for QCTiP 2025 are now open.
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Joschka Roffe @qec.codes · 03/12/2024
🎓 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...
informatics.ed.ac.uk
PhD studentship in Quantum Error Correction
Deadline: 31 January 2025 (or until the position is filled)
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Joschka Roffe @qec.codes · 21/11/2024
I've enjoyed teaching students at Edinburgh University about QEC this term. Here I am introducing the famous [[9,1,3]] Shor code.
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.
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Joschka Roffe @qec.codes · 18/11/2024
📢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
quantuminformatics-cdt.ac.uk
QI CDT – EPSRC Centre for Doctoral Training in Quantum Informatics
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Joschka Roffe @qec.codes · 08/01/2024
Hello World!
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