We taught a quantum computer to learn from its own mistakes-- without stopping. Our RL framework repurposes QEC detection events as learning signals to stabilize the system. Result: Improved Logical Error Rates for both Surface and Color codes on Willow! see arxiv: arxiv.org/abs/2511.08493

Great work worth a read if you work on superconducting circuit with flux control!

This weekend I tried another home experiment for my toddler. This one was suggested to me by none other than Michel Devoret! It’s pretty cool. But I was more excited than the kid 😅

Are you a computer scientist and don't know what an OTOC is, but want to understand the problem solved in the recent Nature paper by Google Quantum AI? We wrote a 2-page note that explains the motivation and presents a simplified version of the problem for any input size. scirate.com/arxiv/2510.1...

The same quantum tunneling honored by this year’s #NobelPrize is driving #URochesterResearch @machielblok.bsky.social is building quantum systems that do what classical computers can’t—inspired by the same fundamental questions uofr.us/48o7I0K #QuantumPhysics #QuantumComputing

Well, so much for my post about learning something new this Nobel week! The Physics prize went to J. Clarke, M. Devoret, and J. Martinis, the pioneers of my own field, superconducting circuits. An absolutely foundational work, and so well-deserved. www.nobelprize.org/prizes/physi...

Nobel Prize week is almost here. I enjoy the predictions, but the real highlight for me is the forced exposure to science outside my field. It’s the one week I get a proper dive into research I’d otherwise miss.

With my son, we played with vegetal oil, baking powder and vinegar colored in blue. The effect was really cool!

scottaaronson.blog?p=9170 Scott Aaronson on the recent « quantum advantage » claim. My favorite quote from his comment: « When they simulate the noiseless quantum computation classically, the advantage disappears? WTF?  »

Blog post: "Actually, you can't test if quantum uses complex numbers" algassert.com/post/2501 I doom the concept of that 2021 Nature paper by showing how to compile any distributed quantum protocol into real-only gates while preserving locality.

This work started w/ my struggle to understand fault-tolerant cluster states, and in particular why they always magically implement the same QEC problem as non-MBQC circuits. Understanding this correspondence as chain complex equivalence finally solved it for me, and I hope for other people too :)

Been awhile since I wrote a blog post. Anyways... why haven't quantum computers factored 21 yet? algassert.com/post/2500

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

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!

The recording of my talk on the Implementing the surface code using dynamic circuits at QEC2025 is available online! yale.hosted.panopto.com/Panopto/Page...

Nvidia is releasing their open source tensor network decoder! As a small bonus they used experimental data from the google surface code experiemnt of 2023. I wonder how it would perform on more recent datasets developer.nvidia.com/blog/streaml...

Looks like 3-coupler / hex implementation of the surface code can now tolerate dropout! www.arxiv.org/abs/2508.08116

I will be at the #QEC25 conference at Yale this week! I will be giving a talk on our work on dynamic implementation of the surface code on Monday

I'm often asked if I'll redo the 2019 quantum factoring estimate. Denser storage by yokes, smaller magic factories by cultivation, slimmer approx arithmetic by Chevignard et al… surely the cost is lower now? Yes, it's lower now. security.googleblog.com/2025/05/trac... arxiv.org/abs/2505.15917

Pretty cool work on qudit encoded in GKP. I think this is also the first experimental demo of a Error Corrected Qudit www.nature.com/articles/s41...

Let’s be honest. It’s hard to beat the Surface code!

Detecting region with ZX calculus!

My guess as to why the 3-coupler wasn't discovered before is that it shifts around the flavor of the stabilizers. If you look at the stabilizer at the end of the cycles, for a given measurement qubit in the bulk, the color changes every other round. The 'ear' of the surface code patch shifts a bit.

Tomorrow I'm giving a zoom talk on magic state cultivation at the Simons quantum Colloquium. Apr 8, 10am PST, see simons.berkeley.edu/programs-eve... Cultivation is the (current) culmination of a decade of work ending the reign of T gates as the dominant cost in fault tolerant quantum computation.

Largest factorization done on a quantum computer. Joke aside. That is an extremely instructive work!

In 1h (9am PST or 5pm CET) I will give a talk at the QASAR seminar hosted by @vasmer.bsky.social and @christophe.vuillot.info . I will present our work on implementing 3coupler, walking and iSWAP surface codes!

I really enjoyed the MM session on early history of quantum information. It was really uplifting to listen to. I really love old lab notes, notes and written mails communications from these days. Look way more fun than emails and chat messages we have these days

I tried to take the train down the coast to the March Meeting this year. That was a mistake, we had 3 hours delay on a 4h journey. That was a been painful… but at least there was WiFi !

I am chairing #APSSummit25 session MAR-B18 about packaging. It will be awesome so you should attend! summit.aps.org/events/MAR-B...

Welcome to the Google Quantum team! Happy to have you onboard!

🌟 The 12th Rochester Conference on Coherence and Quantum Science (CQS-12) will be held June 23-27, 2025 in Rochester, NY! 🌟 CQS has a rich history dating back to 1960 and brought together Nobel Laureates & field pioneers. www.sas.rochester.edu/quantum/cqs/... #CQS2025 #QuantumScience #Physics

Intel's Pentium processor (1993). Looking inside the chip , I found a large, complicated circuit just to multiply by 3 (lower right). Why? The Pentium uses a fast technique to multiply 64-bit number and it turns out that 3 is a special case. Let's take a closer look at multiplication... 1/N

A misleading slide shown at QIP2025. The surface code number is 10x too high (should be 0.1% not 1%; see fig 1c of arxiv.org/abs/2408.13687) and the tesseract number omits the worst 18% of shots (see table III of arxiv.org/abs/2409.04628).

@craiggidney.bsky.social invited us to casually discuss the progress of the surface code over the last 10years. It was a lot of fun looking at blues and reds boxes. And the discussion were great!

The march meeting has schedule our experimental work on iSWAP/honeycomb/walking surface code in a theory session. This make me a bit sad, because we spent a lot of effort trying to give as much experimental insight as possible

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...

Check out our new Quantum Device Lab (qudev.ethz.ch) paper on entangling #quantum error corrected logical qubits in superconducting circuits "Realizing Lattice Surgery on Two Distance-Three Repetition Codes with Superconducting Qubits" published on arXiv today ( arxiv.org/abs/2501.04612 ). 1/4

ETH Zurich just put on arXiv an experimental demonstration of lattice surgery between two repetitions codes. arxiv.org/abs/2501.04612

stim is really nice! It’s one of those tools that let you wondering how people managed to do anything before? Also, it’s so fast <3

Happy christmas to everyone!

If you're an early-career faculty member (received their PhD within seven years of submission) in quantum computing, consider applying to Google's Research Scholar Program. The application process is lightweight and the grant comes in the form of an unrestricted gift. research.google/programs-and...

We just put on arXiv a long haul work on "bending" the time-dynamic of the surface code. We demonstrate error suppression from distance 3 to 5 for three different implementations on Willow. The three offer uniques venues for designing new hardware for error corrections. arxiv.org/abs/2412.14360