Josu Etxezarreta Martinez
@katutxakur.bsky.social
PhD in Quantum Information. Trying to make quantum computers less noisy.
I am a reseacher at Tecnun. Former visitor at the Cavendish Laboratory (Cambridge).
Rugby player. Rock&Roll.
Opinions are my own.
I am a reseacher at Tecnun. Former visitor at the Cavendish Laboratory (Cambridge).
Rugby player. Rock&Roll.
Opinions are my own.
Reposted by Josu Etxezarreta Martinez
Dear funding agencies,
I know we all want to discover the wonder drug that will cure the horrible diseases, but to do that, we need to invest in basic, unsexy, foundational research on how the systems work. Funding can’t all be drug development.
Sincerely,
Looking for basic research grants.
I know we all want to discover the wonder drug that will cure the horrible diseases, but to do that, we need to invest in basic, unsexy, foundational research on how the systems work. Funding can’t all be drug development.
Sincerely,
Looking for basic research grants.
October 14, 2025 at 7:24 PM
Dear funding agencies,
I know we all want to discover the wonder drug that will cure the horrible diseases, but to do that, we need to invest in basic, unsexy, foundational research on how the systems work. Funding can’t all be drug development.
Sincerely,
Looking for basic research grants.
I know we all want to discover the wonder drug that will cure the horrible diseases, but to do that, we need to invest in basic, unsexy, foundational research on how the systems work. Funding can’t all be drug development.
Sincerely,
Looking for basic research grants.
Reposted by Josu Etxezarreta Martinez
Ever wanted to use virtual Z gates with arbitrary powers of SWAP? Introducing the virtual Z pulse: arxiv.org/abs/2509.13453. In our new article, we present a method for distorting a pulse sequence to implement single-qubit Z controls virtually.
From virtual Z gates to virtual Z pulses
Virtual $Z$ gates have become integral for implementing fast, high-fidelity single-qubit operations. However, virtual $Z$ gates require that the system's two-qubit gates are microwave-activated or nor...
arxiv.org
September 18, 2025 at 9:33 AM
Ever wanted to use virtual Z gates with arbitrary powers of SWAP? Introducing the virtual Z pulse: arxiv.org/abs/2509.13453. In our new article, we present a method for distorting a pulse sequence to implement single-qubit Z controls virtually.
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
August 6, 2025 at 11:33 AM
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
Reposted by Josu Etxezarreta Martinez
How fast can quantum processors run? My coauthors and I answer in our new npj Quantum Information article! Utilising pulse engineering, we prepare molecular ground states in a few nanoseconds, ~100× faster than with gates. Back-of-the-envelope: Simulations can now tolerate T₁ and T₂ ~100× smaller.
Minimal state-preparation times for silicon spin qubits - npj Quantum Information
npj Quantum Information - Minimal state-preparation times for silicon spin qubits
www.nature.com
July 5, 2025 at 10:22 AM
How fast can quantum processors run? My coauthors and I answer in our new npj Quantum Information article! Utilising pulse engineering, we prepare molecular ground states in a few nanoseconds, ~100× faster than with gates. Back-of-the-envelope: Simulations can now tolerate T₁ and T₂ ~100× smaller.
Reposted by Josu Etxezarreta Martinez
Hi all! I am excited to finally share this suite of quantum optimal control libraries that run up to 100× faster than QuTiP for some tasks. We developed these libraries while working on our preprint arxiv.org/abs/2406.10913, which was recently accepted into npj Quantum Information—keep tuned!
(1/7)
(1/7)
June 17, 2025 at 6:03 AM
Hi all! I am excited to finally share this suite of quantum optimal control libraries that run up to 100× faster than QuTiP for some tasks. We developed these libraries while working on our preprint arxiv.org/abs/2406.10913, which was recently accepted into npj Quantum Information—keep tuned!
(1/7)
(1/7)
Reposted by Josu Etxezarreta Martinez
I remember getting a $300k grant 10 years ago to perform non-abelian braiding in 2 years
It is funny, but it is also sad. "The people" want miracles from science, right now, and for free. If one is achieved, they move on immediately and just want more, different, fresh like distracted children.
It is funny, but it is also sad. "The people" want miracles from science, right now, and for free. If one is achieved, they move on immediately and just want more, different, fresh like distracted children.
My favorite roadmap is from 2004: qist.lanl.gov/qcomp_map.sh...
“By the year 2007, to
* encode a single qubit into the state of a logical qubit formed from several physical qubits,
* perform repetitive error correction of the logical qubit”
“By the year 2007, to
* encode a single qubit into the state of a logical qubit formed from several physical qubits,
* perform repetitive error correction of the logical qubit”
qist.lanl.gov
June 5, 2025 at 6:20 AM
I remember getting a $300k grant 10 years ago to perform non-abelian braiding in 2 years
It is funny, but it is also sad. "The people" want miracles from science, right now, and for free. If one is achieved, they move on immediately and just want more, different, fresh like distracted children.
It is funny, but it is also sad. "The people" want miracles from science, right now, and for free. If one is achieved, they move on immediately and just want more, different, fresh like distracted children.
Reposted by Josu Etxezarreta Martinez
👇
I think a lot about how Aaron Swartz committed suicide while facing a probably long jail sentence for download some of JSTOR, but no one at Meta is going to face any repercussions for using all of Libgen to train its AI.
Someone else said something very similar to this the other day, but.
It really burns me that our (millennials') generation was legally terrorized for like, downloading Radiohead discographies
But we're supposed to be ok with billionaires stealing human intellectual output in its entirety bc AI
It really burns me that our (millennials') generation was legally terrorized for like, downloading Radiohead discographies
But we're supposed to be ok with billionaires stealing human intellectual output in its entirety bc AI
June 2, 2025 at 1:47 PM
👇
Reposted by Josu Etxezarreta Martinez
Check out our latest preprint! The meme summarizes it.
May 26, 2025 at 10:08 AM
Reposted by Josu Etxezarreta Martinez
An open call for all #QuantumErrorCorrection researchers to now summarise their work in the form of memes please 🙂 - nice work @katutxakur.bsky.social et al (both the paper and meme!)
#QECpapers
#QECpapers
Check out our latest preprint! The meme summarizes it.
May 26, 2025 at 9:22 AM
An open call for all #QuantumErrorCorrection researchers to now summarise their work in the form of memes please 🙂 - nice work @katutxakur.bsky.social et al (both the paper and meme!)
#QECpapers
#QECpapers
Check out our latest preprint! The meme summarizes it.
May 26, 2025 at 8:49 AM
Check out our latest preprint! The meme summarizes it.
Reposted by Josu Etxezarreta Martinez
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
Yes, it's lower now.
security.googleblog.com/2025/05/trac...
arxiv.org/abs/2505.15917
May 23, 2025 at 1:25 PM
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
Yes, it's lower now.
security.googleblog.com/2025/05/trac...
arxiv.org/abs/2505.15917
Reposted by Josu Etxezarreta Martinez
We’d love to find more #QEC experts here on BlueSky and have created this starter pack to help connect the error correction community.
It’s just a start – if you’re working QEC, please follow this account and message us. We’ll happily add you to the pack!
go.bsky.app/RiZfVco 🧪
🧵[2/2]
It’s just a start – if you’re working QEC, please follow this account and message us. We’ll happily add you to the pack!
go.bsky.app/RiZfVco 🧪
🧵[2/2]
Riverlane's Quantum Error Correction Pack
Join the conversation
go.bsky.app
May 9, 2025 at 10:41 AM
We’d love to find more #QEC experts here on BlueSky and have created this starter pack to help connect the error correction community.
It’s just a start – if you’re working QEC, please follow this account and message us. We’ll happily add you to the pack!
go.bsky.app/RiZfVco 🧪
🧵[2/2]
It’s just a start – if you’re working QEC, please follow this account and message us. We’ll happily add you to the pack!
go.bsky.app/RiZfVco 🧪
🧵[2/2]
Reposted by Josu Etxezarreta Martinez
"By the time we get to million qubits, I will be dead."
--John Martinis
Industry expectations vs actual progress in one of his slides:
--John Martinis
Industry expectations vs actual progress in one of his slides:
April 22, 2025 at 5:43 PM
"By the time we get to million qubits, I will be dead."
--John Martinis
Industry expectations vs actual progress in one of his slides:
--John Martinis
Industry expectations vs actual progress in one of his slides:
Check out our latest preprint: SpinHex: A low-crosstalk, spin-qubit architecture based on multi-electron couplers. scirate.com/arxiv/2504.0...
April 7, 2025 at 11:30 AM
Check out our latest preprint: SpinHex: A low-crosstalk, spin-qubit architecture based on multi-electron couplers. scirate.com/arxiv/2504.0...
Reposted by Josu Etxezarreta Martinez
Estas cosas no hacen más que acentuar la desconfianza de los jóvenes en la carrera académica. Lo que necesitamos son inversiones recurrentes, planificadas y predecibles. 1/
La desesperación de los investigadores de posdoctorado por un contrato de la Junta de Andalucía que nunca llega
La desesperación de los investigadores de posdoctorado por un contrato de la Junta de Andalucía que nunca llega
El Gobierno de Moreno Bonilla convocó en noviembre de 2023 unas ayudas a posdoctorados que aún no se han adjudicado, una demora que ha condicionado su futuro personal y profesional
elpais.com
April 6, 2025 at 6:46 AM
Estas cosas no hacen más que acentuar la desconfianza de los jóvenes en la carrera académica. Lo que necesitamos son inversiones recurrentes, planificadas y predecibles. 1/
Reposted by Josu Etxezarreta Martinez
"overcome your inner resistance; it is always a mistake to try to do things too cleverly" - Einstein in a letter to Leo Szilard
April 4, 2025 at 3:49 PM
"overcome your inner resistance; it is always a mistake to try to do things too cleverly" - Einstein in a letter to Leo Szilard
Reposted by Josu Etxezarreta Martinez
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!🐱
@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!🐱
March 21, 2025 at 7:47 PM
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!🐱
@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!🐱
Reposted by Josu Etxezarreta Martinez
Improving devices before entering commercialization phase: not bullshit
The startup, launched in 2020, is focusing on improving its devices before it enters a commercialisation phase.
#QuantumComputing #StartupEurope
#QuantumComputing #StartupEurope
Quantum computing startup Alice & Bob raises 100m Series B to double down on R&D and open new production site
sifted.eu
January 30, 2025 at 11:45 AM
Improving devices before entering commercialization phase: not bullshit
Reposted by Josu Etxezarreta Martinez
En España hay 11.914 personas con una fortuna superior a los 30 millones de dólares.
¿Sabías que gracias a Ayuso dos de cada tres ultrarricos españoles no pagan impuesto de patrimonio? No pagan nada porque tienen su fortuna en Madrid.
Pero luego no tiene para la universidades.
¿Sabías que gracias a Ayuso dos de cada tres ultrarricos españoles no pagan impuesto de patrimonio? No pagan nada porque tienen su fortuna en Madrid.
Pero luego no tiene para la universidades.
January 26, 2025 at 9:59 AM
En España hay 11.914 personas con una fortuna superior a los 30 millones de dólares.
¿Sabías que gracias a Ayuso dos de cada tres ultrarricos españoles no pagan impuesto de patrimonio? No pagan nada porque tienen su fortuna en Madrid.
Pero luego no tiene para la universidades.
¿Sabías que gracias a Ayuso dos de cada tres ultrarricos españoles no pagan impuesto de patrimonio? No pagan nada porque tienen su fortuna en Madrid.
Pero luego no tiene para la universidades.
Reposted by Josu Etxezarreta Martinez
I saw the best minds of my generation destroyed by madness, starving hysterical naked,
dragging themselves through the academic halls at dawn applying for a new grant
dragging themselves through the academic halls at dawn applying for a new grant
Researchers spend approximately 45% of their time on administrative activities related to #grants rather than actual #research. The current #competition in research #funding has significant drawbacks; evidence-based improvements of the funding system are required: www.pnas.org/doi/10.1073/...
The costs of competition in distributing scarce research funds | PNAS
Research funding systems fundamentally influence how science operates. This paper
aims to analyze the allocation of competitive research funding fr...
www.pnas.org
January 4, 2025 at 3:18 PM
I saw the best minds of my generation destroyed by madness, starving hysterical naked,
dragging themselves through the academic halls at dawn applying for a new grant
dragging themselves through the academic halls at dawn applying for a new grant
Reposted by Josu Etxezarreta Martinez
“The true measure of learning is not the time and energy you put in. It’s the knowledge and skills you take out.”
By @adamgrant.bsky.social
www.nytimes.com/2024/12/26/o...
By @adamgrant.bsky.social
www.nytimes.com/2024/12/26/o...
Opinion | No, You Don’t Get an A for Effort
High marks reward excellence, not grit.
www.nytimes.com
December 26, 2024 at 9:29 PM
“The true measure of learning is not the time and energy you put in. It’s the knowledge and skills you take out.”
By @adamgrant.bsky.social
www.nytimes.com/2024/12/26/o...
By @adamgrant.bsky.social
www.nytimes.com/2024/12/26/o...
Check out our latest preprint "Asymptotically good CSS-T codes exist". There is also a nice discussion about in on scirate.com/arxiv/2412.0...
December 17, 2024 at 3:02 PM
Check out our latest preprint "Asymptotically good CSS-T codes exist". There is also a nice discussion about in on scirate.com/arxiv/2412.0...
Reposted by Josu Etxezarreta Martinez
I created a transcript of my talk at the Q2B Conference: "Beyond NISQ: The Megaquop Machine." You can read it here:
quantumfrontiers.com/2024/12/14/b...
quantumfrontiers.com/2024/12/14/b...
Beyond NISQ: The Megaquop Machine
On December 11, I gave a keynote address at the Q2B 2024 Conference in Silicon Valley. This is a transcript of my remarks. The slides I presented are here. NISQ and beyond I’m honored to be back at…
quantumfrontiers.com
December 14, 2024 at 4:25 PM
I created a transcript of my talk at the Q2B Conference: "Beyond NISQ: The Megaquop Machine." You can read it here:
quantumfrontiers.com/2024/12/14/b...
quantumfrontiers.com/2024/12/14/b...