Diego Ruiz

And for instance, you can also prepare a Cx-Cx-X state (a Hadamard CCZ) by unfolding the [[8,3,2]] 3D color code
The suppression scales in p², which is a bit weak, but maybe larger unfolded codes can push the fidelity further, something to explore!
cc @christophe.vuillot.info

18.07.2025 14:42 — 👍 2    🔁 0    💬 0    📌 0

Why does it work? The 15 Reed-Muller is 3D, but if one error type dominates, you only need to measure the weight-4 stabilizers, not the weight-8 ones
The nice part is you can unfold these weight-4 checks in 2D!
And this unfolded code can be also merged with a thin surface code

18.07.2025 14:40 — 👍 1    🔁 0    💬 1    📌 0

And even with a noise bias as low as 80, a magic state of the same fidelity can be prepared with 175 qubits in the same amount of time
The key insight is that the noise bias enables you to perform distillation at the physical level rather than at the logical level

18.07.2025 14:40 — 👍 1    🔁 0    💬 1    📌 0

Unfolded distillation: very low-cost magic state preparation for biased-noise qubits Magic state distillation enables universal fault-tolerant quantum computation by implementing non-Clifford gates via the preparation of high-fidelity magic states. However, it comes at the cost of sub...

Probably the last paper of my PhD! We show that biased-noise qubits can greatly reduce the cost of magic state preparation

With high noise bias, just 53 qubits and ~10 error correction cycles are enough to prepare a magic state with logical error≈1e-7
arxiv.org/abs/2507.12511

18.07.2025 14:39 — 👍 20    🔁 1    💬 2    📌 0

Diego presenting his work under the expert eye of Craig Gidney

Summary slide of Diego's results

Two talks of Alice&Bob QEC team in parallel this morning:

@diego-ruiz.bsky.social presented his new results on distillation with biased-noise qubits: with bias=30 he already gets 150x reduction!

I talked about implementing rotor codes

So many fun subjects to work on, join our team we are hiring!🐱

21.03.2025 19:47 — 👍 18    🔁 2    💬 2    📌 0

1️⃣ It's surprisingly close to the theory, the suppression of bitflips has never been this strong, the lifetime is multiplied by e^4≈50 for every added photon instead of e^2≈7

2️⃣ The bitflip saturates at the same value as the normal cat, a few minutes (cosmic rays?)

14.02.2025 16:37 — 👍 3    🔁 0    💬 0    📌 0

Enhancing dissipative cat qubit protection by squeezing Dissipative cat-qubits are a promising architecture for quantum processors due to their built-in quantum error correction. By leveraging two-photon stabilization, they achieve an exponentially suppres...

First realization of a dissipatively stabilized squeezed cat qubit (a slight variation that we called a moon cat 🌛 actually), it was super interesting to work on this with experimentalists!
arxiv.org/abs/2502.07892
My two key takeaways ⬇️⬇️

14.02.2025 16:36 — 👍 11    🔁 3    💬 1    📌 0

LDPC-cat codes for low-overhead quantum computing in 2D - Nature Communications Implementing full quantum error correction incurs a significant hardware overhead. Here, the authors propose a quantum computing architecture combining superconducting cat qubits with 2D local LDPC co...

Happy to share our work with @anthony-leverrier.bsky.social, @christophe.vuillot.info, Jérémie Guillaud and Mazyar Mirrahimi on the LDPC-cat architecture was published in Nature Communications! Thanks to the reviewers for their useful feedback
www.nature.com/articles/s41...

29.01.2025 18:57 — 👍 20    🔁 5    💬 1    📌 1