@RobertHuangHY It may be worth noting that factoring 2048-bit integers is estimated to require around 13,000 qubits when a microwave memory is incorporated into the architecture journals.aps.org/prl/abstract/1…
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Nicolas Sangouard
83 posts
Nicolas Sangouard
@NSangouard
Research in #quantum #computing and #communication with team Quantum Information Theory @CEA_Officiel
Paris-Saclay Katılım Mart 2021
50 Takip Edilen65 Takipçiler
❓How many qubits are needed to break cryptographic systems🔐, e.g., ECC-256 in BTC?
With a new fault-tolerant quantum architecture arxiv.org/abs/2603.28627, ECC-256 can now be broken with ~10k atomic qubits.
The largest atom array has 6k+ atomic qubits: arxiv.org/abs/2403.12021
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@CraigGidney arxiv.org/abs/2602.11457 clarifies what we gain from using LDPC codes. It offers valuable guidance for the community—both on whether improving current connectivity is worthwhile and on the need for fast, efficient decoders.
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@CraigGidney What does built-in memory add to a computing architecture?
How do stabilized cat qubits compare with standard transmons?
arxiv.org/abs/2103.06159 and
arxiv.org/abs/2302.06639 provide concrete answers.
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I've been asked several times to comment on arxiv.org/abs/2602.11457, which claims to reduce the qubit cost of factoring by 10x.
My take is that they demand a *lot* more qubit connectivity for that number. Your mileage depends entirely on how plausible you find those demands.
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Recently, we showed that any universal gate set necessarily includes gates that are hard to implement with unitary circuits on biased-noise stabilizer codes.
Very excited to see this work heading toward publication in @PhysRevLett! 🎉
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Taken right before M. Devoret’s Nobel lecture 📸
You may recognize two of my greatest colleagues from @CEA_Officiel. Both spent time at @UCBerkeley during the period when the results later honored by this year’s Nobel Prize were taking shape.
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@APSphysics @PhysRevLett Outstanding work led by Pierre Cussenot and Bastien Grivet, and made possible through a great collaboration between @CEA_Officiel, @ICFOnians, University of Innsbruck, and @UCPH_Research as part of the EU Quantum Internet Alliance (@eu_qia).
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Excited to see this work published in @APSphysics journal @PhysRevLett 135, 240803 (2025)! 🎉
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With piecewise photon shaping in AFC memories, we bridge systems that interact with light on very different timescales and show that ion–AFC memory architectures can distribute entanglement over hundreds of km. Excited to see this work heading toward publication in @PhysRevLett!
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@CEA_Officiel @CEAParisSaclay @cea_grenoble @CEAMarcoule @CEACadarache J. Martinis n'a t il aussi passé du temps au CEA, en tant que postdoc?
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#NobelPrize 🏆| De Saclay à Yale, un parcours d’exception récompensé par le Nobel 🤩
👏 Le CEA félicite Michel Devoret ainsi que ses co-lauréats, et salue ce parcours international exemplaire qui illustre l’universalité de la science.
En savoir + 👉 bit.ly/4gZE4RP
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Check this out: Major credit to @simonstorz and the @AndreasAtETH group for this first complete self-testing experiment!
Andreas Wallraff@AndreasAtETH
Check out our newest paper entitled "Complete Self-Testing of a System of Remote Superconducting Qubits" published this week in the @APSphysics journal @PhysRevLett as Phys. Rev. Lett. 135, 030801 (2025): journals.aps.org/prl/abstract/1… . In this paper we use the outcomes of loophole-free Bell tests to determine the fidelity of entangled states and the fidelity of qubit readout free of any assumptions about the experimental set up. Find our more by following the link above. The work was done by @simonstorz , Anatoly Kulikov, Josua Schär, Victor Barizien, Xavier Valcarce, Florence Berterottière, Nicolas Sangouard, Jean-Daniel Bancal, and @AndreasAtETH in a collaboration between our @qudev Lab at @ETH_physics, the @ETHQuantumCntr, and @ETH_en Zürich with the Université Paris-Saclay.
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Modular quantum computing, with small processors linked by quantum networks, is a leading path toward fault-tolerance.
But what does it take for the network to truly support distributed quantum computing?
We explore this in arxiv.org/pdf/2504.08891
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2/2 We show that any universal gate set necessary includes operations that are hard to realize with unitary circuits on classical and biased-noise stabilizer codes.
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1/2 Stabilizer codes tailored to biased noise can greatly reduce qubit overhead for executing quantum algorithms. But which logical gates remain easy to implement directly on such codes?
scirate.com/arxiv/2507.054…
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Rejoignez-nous, @ManuFlurin et moi, pour une discussion sur le quantique avec @laboiteacuriosites. On vous attend Jeudi à 19h!
CEA@CEA_Officiel
#Quantique🐱| J-2 avant une plongée décalée et accessible dans le monde quantique ! 🎮🧱 📅 RDV jeudi 12 juin à 19h avec nos experts CEA, @NSangouard & Emmanuel Flurin, pour notre nouvelle conférence exclusive, animée par @laboiteacuriosites 👉 youtu.be/6p1vQVZ__ZY?si…
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@CraigGidney Agreed. Any known techniques for in-place multiplication? Inversion could be derived from its conjugate transpose and one can expect up to a 3× qubit reduction for the elliptic curve discrete log.
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Quantum attacks on elliptic curve crypto have costs dominated by one operation: uncomputing a division (see fig15 and fig20 of arxiv.org/abs/2302.06639).
Masking makes it easy to *compute* a division, but isn't reversible (arxiv.org/abs/2008.04577). A strange situation. Fixable..?
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@CraigGidney Since the remark was already noted in arxiv.org/abs/2008.04577, should I assume you've managed to fix it?
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Nicolas Sangouard retweetledi
#Quantique🐱| Vous vous souvenez de la toupie, du cigare et de la console ?
📍 RDV le 12 juin à 19h sur notre chaîne YouTube pour une conférence pas comme les autres : "La physique quantique : de Schrödinger à Minecraft" 🎮 animée par @curiosiboite 👉@CEA" target="_blank" rel="nofollow noopener">youtube.com/@CEA
GIF
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