Arne L. Grimsmo

Apparently September 5th is "cultivate with fold-transversal S" day:

arxiv.org/abs/2509.05232

arxiv.org/abs/2502.017...

arxiv.org/abs/2509.05212

Exciting cultivation updates from my collaborator @yotamvaknin.bsky.social!

Come join the (classical) simulation (of quantum systems) team at AWS!

of course that Cultivation works really well, so you get some very low logical error rates. I think you could still contemplate an architecture where you use erasure qubits in the cultivation patch, but not the rest of the quantum computer, so that the extra engineering cost is not too big.

results though, @craiggidney.bsky.social-Shutty-Jones came out with Cultivation, so we had to redo all the analysis. With Cultivation you don't get that much of a boost by just improving the Injection anymore, so the cute observation that you just need 3 erasure qubits doesn't work. The upshot is

Originally, when we started looking at this almost 1.5 yrs ago now, I was very excited about the fact that you just need a small, constant (3 to be exact) number of erasure qubits in an injection patch, independent of the target size of the final surface code. Before we got around to writing up the

Shoham Jacoby on X: "Published a new preprint with @yotamvaknin #Alexretzker @ArneGrimsmo! We show that using erasure qubits can enable cleaner magic state injection and cultivation, potentially allowing for the generation of application-ready magic states without distillation. 🧵+ meme at the end https://t.co/Kr5KeIUW0P" / X Published a new preprint with @yotamvaknin #Alexretzker @ArneGrimsmo! We show that using erasure qubits can enable cleaner magic state injection and cultivation, potentially allowing for the generation of application-ready magic states without distillation. 🧵+ meme at the end https://t.co/Kr5KeIUW0P

This was a fun project looking at erasure qubits for magic state injection and cultivation, with Shoham Jacoby, @yotamvaknin.bsky.social, and Alex Retzker: x.com/shohamjacoby...

Someone should write "Game of qLDPC codes" along the lines of Litinski's classic for surface codes and review all the recent stuff on computation for us non-experts.

Nice!

Universal fault tolerant quantum computation in 2D without getting tied in knots We show how to perform scalable fault-tolerant non-Clifford gates in two dimensions by introducing domain walls between the surface code and a non-Abelian topological code whose codespace is stabilize...

Are you a fan of fault-tolerant non-Clifford gates on the 2D surface code?

Have you been wondering what was really going on in the protocols by Bombín and Brown?

We have a new work for you: arxiv.org/abs/2503.15751

2D transmons with lifetimes and coherence times exceeding 1 millisecond Materials improvements are a powerful approach to reducing loss and decoherence in superconducting qubits because such improvements can be readily translated to large scale processors. Recent work imp...

Our paper that tells you how to make millisecond transmons just appeared. Congrats Matthew, Faranak, and team! In collaboration with Nathalie de Leon and Bob Cava, and building on five years of work in C2QA, one of the five DOE National Quantum Initiative Centers.

arxiv.org/abs/2503.14798

Breaking! Leaked photo from Amazon quantum computing lab running repetition code on 5 cat qubits!
Paper: www.nature.com/articles/s41...
Photo: coleandmarmalade.com/2022/05/10/f...

Today Nature published measurement results from Ocelot, the new quantum chip created at the AWS Center for Quantum Computing at Caltech.

There is still far to go, but we hope that Ocelot’s unique architecture will shorten the path to quantum utility that benefits the world.

Congrats!

How does one sign up to just listen? 🙂

Nice!

That’s awesome, thanks! I still wish my Discover feed was less pictures of space though.

I get too many space pictures in my Bluesky feed. How to tell the algorithm I’m just here for quantum?

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...

The best conference series on quantum error correction and fault tolerance is back! Submissions are now open for QEC 2025 that will take place in Yale this August.

the next decade, but that it might take another to get to "very useful." The pessimistic take is that none of technologies we think are most promising right now can scale to really big systems, in which case it may take a lot longer to get to "very useful."

Mostly agree with this optimistic take by Huang. I think it could take longer given that none of the currently pursued qubit technologies are totally convincing yet, and they all face some serious engineering cliffs we don't know how to solve. My optimistic take is that we see a "winner" emerge over

A Constructive Approach to Zauner's Conjecture via the Stark Conjectures We propose a construction of $d^2$ complex equiangular lines in $\mathbb{C}^d$, also known as SICPOVMs, which were conjectured by Zauner to exist for all d. The construction gives a putatively complet...

Have SIC-POVMs finally been found? @sflammia.bsky.social arxiv.org/abs/2501.03970

Roadtrip! Heading from @equscoe.bsky.social EQUS workshop in Noosa to the @psiquantum.bsky.social Brisbane office opening, with Tom Stace and Andrew Doherty. In Gerard Milburn’s car! Going to be a very #quantum drive

we need a program where skilled software developers can get a visa really fast

call it the O(1) visa

New essay: "How to be a wise optimist about science and technology?"

michaelnotebook.com/optimism/ind...

Details | Open Rank Faculty, Quantum Systems | Careers | Division of Human Resources | Virginia Tech

We're hiring quantum theory faculty at Virginia Tech. This is an open-rank position in the CS or EE department at the new Center in Alexandria, VA, just outside of Washington, DC. This is the first of several new hires at the Center. Come join us (pls RT)!
careers.pageuppeople.com/968/cw/en-us...