Entangling QPUs to Build a Quantum Data Center
Overview
In this episode of The Quantum Spin by HKA, host Veronica Combs interviews Carmen Palacios-Berraquero, founder and CEO of Nu Quantum. They discuss the company’s entanglement fabric, a cutting-edge mechanism for connecting individual quantum processors into a larger, more powerful machine. Carmen also explains the importance of industry collaboration as supported by the new Quantum Datacenter Alliance. Nu Quantum is also developing a quantum networking test bed. Join this enlightening discussion for an insider’s view on the next frontier of quantum computing.
00:00 Introduction to The Quantum Spin Podcast
00:35 Interview with Carmen Palacios Berraquero: Nu Quantum’s Vision
00:53 Understanding the Entanglement Fabric
04:14 Qubit Modalities and Networking
06:19 Nu Quantum’s Rack-Mounted Solutions
07:34 Building a Strong Company Culture
11:31 The Quantum Data Center Alliance
16:03 Government Support and Future Plans
17:55 Exciting Announcements and Test Bed Development
19:50 Conclusion and Farewell
Dr. Carmen Palacios-Berraquero is the Founder and Chief Executive of Nu Quantum, the leading quantum entanglement company, which recently raised a £8.5M pre-Series A from leading VCs including Amadeus Capital, IQ Capital, and the National Security Strategic Investment Fund (NSSIF). She is an award-winning quantum physicist and inventor, author of several high-impact research papers and a book based on her doctoral research. Prior to founding Nu Quantum, Carmen earned her PhD in physics at the University of Cambridge and undergraduate degree at Imperial College London. She also serves on the Technical Advisory Board of the UK’s National Quantum Computing Centre and is Cofounder and Director of UKQuantum, the UK’s quantum industry group. She has been the leader of several pro-equality and LGBTQIA+ visibility groups, and initiatives in STEM.
Transcript
[00:00:00] Veronica: Hello, and welcome to The Quantum Spin by HKA. I’m Veronica Combs. I’m a writer and an editor here at the agency. I get to talk every day with really smart people working on really fascinating subjects, everything in the Quantum industry, from hardware to software. On our podcast, we focus in on quantum communication, and by that I don’t mean making networks safe from hacking or entangling photons over long distance, but talking about the technology.
[00:00:26] How do you explain these complicated concepts to people who don’t have a background in science and engineering but want to understand all the same?
[00:00:34] Today. I’m talking with Carmen Palacios Berraquero, who is the founder and CEO of Nu Quantum. And this company is one of the original quantum networking companies, and I’m really excited to talk to you today, Carmen, about entanglement fabric and data centers and qubits.
[00:00:51] Carmen: Thanks, Veronica. It’s a pleasure to be here.
[00:00:53] Veronica: So Nu Quantum is building the entanglement fabric to unlock commercial quantum computing scale out. And when I think about what that means to a data center operator or a CIO, I think about the connective tissue that connects all these separate quantum computers into a more powerful system.
[00:01:11] How does the entanglement fabric work?
[00:01:13] Carmen: So it is the connecting fabric, the connective tissue that can create a large and efficient distributed quantum computer out of smaller quantum processing units and how the entanglement fabric works. If we start by focusing on what the entanglement part is about even though I’m sure the listeners of this podcast are familiar with entanglement is that strong correlation between qubits that alongside superposition
[00:01:41] powers a quantum computer makes it powerful. So inside each QPU or quantum processing unit, there will be qubits that are entangled together in a particular connectivity. So it could be all-to-all or nearest neighbors, right? And that connectivity of entanglement matters for how powerful, how good the computer is.
[00:02:01] Okay, so then if you want to connect processors together, what you need to do is that you need to create entanglement links, the same kind of entanglement links that exist between qubits inside a processor. You need to create those same links between qubits in different processors. So the first thing that the entanglement fabric does is create links between qubits in distant processors or in separate processors that are not so distant.
[00:02:31] They’re probably in a data center. Yes. And then, so those are the sort of individual stitches, if you will. But then what makes it the fabric is that via our photonic switching network, our control and orchestration, we can weave that fabric. We could create those stitches again in the connectivity that we want.
[00:02:52] And if we now zoom out, what we have is a larger computer with qubits, entangled with each other, with a particular connectivity, which again dictates how good the computer is. The power of the entanglement fabric is that then you can create an efficient computer because that connectivity of entanglement can be well suited for example, quantum error correction.
[00:03:15] And so we are just essentially creating a larger computer by weaving together small processors via entanglement.
[00:03:22] Veronica: Yes, I was interviewing an analyst the other day and he said it doesn’t make sense to have all these computers unless they can work together and make one bigger computer.
[00:03:29] That’s how you’re gonna make it, actually to scale and to do something interesting. And I had been so focused on the individual machines, right? What’s the error rate and what’s the modality and how many logical qubits do you have? But yes, that’s obviously what has to happen next is connecting them all.
[00:03:45] Carmen: And, you know. how good the individual processor is, is extremely important. We need to focus on that too. Unless we reach particular error thresholds inside the individual computers, we can connect many, but the computer as a whole won’t be as good. So that’s, don’t get me wrong, that’s really important.
[00:04:03] That’s fundamental. But in order to cross the threshold from R&D to commercial utility, we simply need a network that is as good as the processors.
[00:04:14] Veronica: How does the entanglement fabric work with different qubit modalities? I know the long term plan is for it to be flexible enough to work with whatever the modality may be.
[00:04:22] Is that right?
[00:04:22] Carmen: That’s right. So the entanglement fabric concept applies to all kinds of qubits, all kinds of qubits work via creating entanglement between them. And it is possible to photonically network or photonically create entanglement between any kind of qubit. There are some qubits that are more suited to it.
[00:04:42] There are some qubits where the technology is still in development, the industry perception is that we can network, photonically network, all kinds of qubits. How we like to say it is that the hardware is qubit adaptable. Mm-hmm. So, In the architecture there is first an interface between the qubit and the network.
[00:04:59] So a plug that creates the entanglement between the processor and the network. And that is the part that changes more between kinds of qubits. So we have a portfolio of those. We’ve developed an interface for trapped ions, for neutral atoms. And wow. there are companies out there that develop these sorts of interfaces for superconducting and spin qubits.
[00:05:19] And we partner with some of those companies. And then the next step is this sort of analogous to the classical router that, routing photons around the control and orchestration. This is very simply qubit adaptable. So the quantum networking unit that we’ve recently launched is designed in a modular way we can swap in and out the optical module and
[00:05:41] just change it with its wavelength and the rate of operation, and then it will be adapted to different kinds of qubits. And then the last part, which I just mentioned briefly before, is around error correction. And this part, the architecture of that is essentially qubit agnostic. So yeah, absolutely this, it is a horizontal layer of the quantum computing stack.
[00:06:01] Veronica: Right. Right. Wow, that’s amazing. There’s so much amazing engineering and design in these machines. I think we’re pretty much convinced a lot of people, maybe not everyone, but a lot of folks that quantum is out of the sort of dark corners of a lab and it’s out into the real world.
[00:06:16] And I have to say nothing says ready to deploy like a rack mounted solution. And I was reading about the networking device that Nu Quantum released, I think at the end of 2024. And that was a key feature of the product. So did you know from the start of product development that it had to be in this form factor?
[00:06:32] It had to be ready to put on a rack?
[00:06:34] Carmen: From the beginning when we started designing the quantum networking unit, which again, is analogous to the classical router. It has a photonic switching layer, a photonic entanglement layer, and a control and orchestrator. We’ve always designed it in a way that was from the get go, going to be robust
[00:06:55] enough to deploy in a sort of data center environment. And that’s to do with temperature, vibrations and things like that, power, and then in a way that it’s again, modular because we already know that we’ll need a few kinds of quantum networking units to work with different kinds of qubits.
[00:07:13] And that’s already paying off. We already have really good commercial inbound interest. These are companies that work with different kinds of qubits already. And that sort of foresight for my product team is now paying off because we can tailor, easily tailor the quantum networking unit to work with different customers.
[00:07:32] Veronica: Right, right. So I did also wanna talk about the other important part of your company, and that’s the people that are doing all of this work. Your team has grown from less than 20 people to more than 60 in the last year, I believe. And I was excited to see that your leadership team is 75% women. I know building a strong culture is important to you in your philosophy of work.
[00:07:52] How have you made that a priority at Nu Quantum?
[00:07:55] Carmen: It’s been a priority since the beginning. And I think that’s really important because it’s really hard to change culture once you’re more than five or 10 people. Mm-hmm. Mm-hmm. But if the seed has the right culture and it prioritizes those things from the beginning, culture and diversity.
[00:08:17] Then actually, it’s something that grows positively on it, on its own. Because what happens is that, the people that apply to Nu Quantum are interested in working. And, the company at the frontier of quantum networking that is developing this cool technology, but also a company that they can see
[00:08:35] prioritizes the wellbeing and the experience of its people and where everyone can thrive. And we put a lot of effort into that. So I think having, you know, not doing it retroactively like, oh, first I’ll build a company and then I’ll see how I can retrofit diversity or something into it or culture that I don’t think that works.
[00:08:56] If it’s there from the beginning, then it’s more sustainable. And then now we’re at the level of people we’re, yeah, 65 or so, and we’re undergoing another big transition towards a hundred or so, where the way we prioritize culture will look different. The tools we use, the methods, the conversations look different.
[00:09:17] But still, it’s at the table. It’s up there in the objectives of the company
[00:09:22] Veronica: and how have you seen diversity benefit the company?
[00:09:25] Carmen: A range of things. It’s really, it’s really beautiful. First of all, in just in recruitment, as I said, so many people I interview every single person that joins Nu Quantum and
[00:09:37] you’d be surprised by the amount of people that you know then go on to be, incredible contributors tell me that they apply because they see that this is a company that cares about that and they can see that it’s not, it’s not just words, but it’s actually how it’s genuine.
[00:09:55] Yes, it’s genuine. So that’s one way. And then there’s maybe two other things, I think, how I can see individuals develop, people feeling safe to push themselves and thrive no matter where they come from or what they look like, or you know who they are.
[00:10:11] And then when you put together a range of people that are so different, we come up with actual breakthroughs. So you know what I was talking about the entanglement fabric, this is really the first proposition of how one would scale out. How one would build a quantum data center in a fault tolerant way using matter qubits and photons.
[00:10:36] It’s, you know, It’s something that wasn’t there before. That sort of breakthrough comes from people from wildly different disciplines and backgrounds coming together and collaborating, from the experts in photonics and qubits and entanglement to the experts in quantum error correction and high performance compute, you know, it’s what gets those step changes.
[00:11:02] I’ve seen it so clearly.
[00:11:03] Veronica: When you think about the full range of perspectives on anything on how to use an app or how to entangle qubits or I don’t even know how to pick a place to go to dinner. When you have that full range, you just see so much more instead of just, everyone went to this school, or everyone came from this consulting company, or everyone’s from this one town.
[00:11:26] When you have the full pie or the full picture, it does just change everything. I also wanted to talk to you briefly about the Quantum Data Center Alliance, which Nu Quantum was one of the founding members, if not the founding member of this organization, which started in March.
[00:11:41] And I believe it’s focused on hardware maturity, benchmarks, interoperability, and standards. This seems like a really important part of the ecosystem. What was your motivation in starting it?
[00:11:51] Carmen: The motivation was helping the industry move to an ecosystem thinking rather than single company thinking.
[00:12:04] Mm-hmm. I think by now everyone knows that building a fault-tolerant quantum computer, not only building it once, but building it multiple times so it’s, you know, accessible to many different end users and actually do something good for the world, that’s not something that one single company is going to achieve.
[00:12:21] Right. I think it’s very true, yes. Everyone understands that now, but maybe not so much a few years ago. And in realizing that, then you realize that we need to start building the ecosystem that will deliver that incredible thing in five years or something. Yes, for sure. So that was really our motivation.
[00:12:42] Who are the people, what are the layers of the quantum computing stack and infrastructure that need to work together to realize this thing? That for us is the QPU providers, the networking providers, the error correction and software providers, and then the data center infrastructure.
[00:13:00] All of those companies need to be able to communicate and efficiently work together, identify where the gaps are, identify where we need some common language about interfaces or benchmarking. We’re not really saying anything new. This has happened in the classical industry before, and so we thought it was the right time and we thought we were a good company to start it because.
[00:13:31] We can work with everyone essentially. We’re not wedded to a particular qubit or architecture. We want everyone to succeed, and ultimately also the vision for the QDA is that at the moment it is very sort of hardware centric, you know? mm-hmm. Let’s build it, but then it is a good forum to start bringing in end users as well.
[00:13:52] And so I think there will be a, the QDA will continue to change as the industry does. But for now it’s about, okay, let’s get together and talk about the things that we haven’t addressed yet, because, we need to connect with each other to do
[00:14:05] Veronica: Right, right. It hasn’t been the time or had the opportunity, but yes.
[00:14:09] I noticed that you hosted a sold out event in June. Were there any sparks that this in-person event generated for the organization?
[00:14:16] Carmen: Yes, absolutely. That was our inaugural event. We’ve been working on the QDA in the background confidentially for about two years now. But we launched it publicly with our co-founders in March or so. So those are Cisco, NTT Data, Quantinuum, Quera, OQC and QphoX. Nu Quantum hosted the first QDA event, the inaugural forum in June in London at the Battersea Power Station.
[00:14:44] And it was a tremendous success. So it was sold out. We brought over a hundred people from really the top quantum industry globally. We had representatives from Google, IBM, Equinix, CESGA, Photonic Inc., PsiQuantum, I mean a lot of the leaders in quantum computing companies, plus a lot of data center companies,
[00:15:09] networking companies. It was a huge success in the sense that not only it was sold out and recognized as an International Year of Quantum official event by UNESCO but also, just the faces of everyone. Towards the end of the event, everyone was still there. There were, you know, two or three empty chairs, but everyone was still there and stayed because it felt quite genuine. We went systematically through the layers of the stack that need to come together. And ask people to really go straight to it, not try to embellish the presentation about the company or anything, but just talk about what are they building, why challenges, et cetera.
[00:15:49] And people did. And so it felt just really useful and genuine and more like a workshop, a big workshop than a conference, right? Yeah.
[00:16:00] Veronica: It was really exciting momentum for the industry, I have to say.
[00:16:03] So I know that the EU has released a quantum strategy recently and countries around the world have released their own quantum strategies. I know there’s one in the UK and the US is trying to renew our quantum initiative. Is there any particular kind of support from governments that you would like to see that would help move the industry forward?
[00:16:20] I don’t know if that’s standards or, I mean, funding is always nice, obviously, but is there anything that would be helpful from a policy perspective?
[00:16:26] Carmen: So obviously fund funding is great but I think funding needs to come via a strategy. So some countries are quite good at that. The UK is pretty good at that. Or has been historically, let’s see what happens next. Other countries may be less so, but I think having that, because if we’re, if this is something that we need to continue to fund via government for at least I believe five years, then you know it can’t be a sort of bits here and there, but I think it needs to come with a strategy.
[00:16:56] And then as we move to commercialization, I think what we really need is also a prioritization of use cases. These are going to be incredibly expensive machines. And we need to use them for something that benefits the planet and society, I believe. And I think governments have a role to play there.
[00:17:24] I think we also need to start getting much crisper about things like energy consumption. Mm-hmm. With the current data center crisis that is, you know, is creating an energy and water crisis, we need to be learning from these mistakes and we need more accountability around that because we’re, we’re gonna get there now.
[00:17:43] We’ll build commercial quantum computers in the next three to five years, and we’ll continue to scale that. Mm-hmm. So now it’s about: what do we want this industry to look like when it actually flourishes.
[00:17:53] Veronica: Right, right. Definitely. So this has been a great year for Nu Quantum. The company was named a Cambridge Technology Company of the Year for this year.
[00:18:02] And I know you were just named one of the top female founders to watch in the industry. What do you have planned for the rest of the year? It seems like you could do a little coasting, just enjoy your success, but I’m sure you have more things on the agenda than that.
[00:18:13] Carmen: Oh, yes.
[00:18:14] We’re planning a lot of good things for the next year. Oh. So, we’ll have an important announcement for the company in the next two, three months that I think will set us up for the next few years. We’re planning on scaling the company again, so we’re hiring. By the way, anyone listening, we are hiring.
[00:18:37] Please look at our website. We are talking to customers about our quantum networking unit. We hope to strengthen some of the relationships with our customers and deploy some of these units so that they can start to be used for quantum networking. Probably the most exciting.
[00:18:54] thing of all, we are building a quantum networking test bed. So we’ll have in the next year some exciting results about how performance this sort of network can be.
[00:19:07] Veronica: Wow. What will the test bed involve?
[00:19:11] Carmen: Entanglement of qubits. So just, yeah, distant entanglement. So first entanglement between a qubit and a photon.
[00:19:19] And then entanglement between two qubits via the photons. So this is something that has only really been demonstrated in academia. That has in terms of performance, hasn’t really reached yet the threshold where it can really be used commercially for computing.
[00:19:41] And, a lot of what we do is engineering the network so that we can improve the performance that has been demonstrated in academia to date.
[00:19:50] Veronica: Well, Thank you so much for your time today, Carmen. It’s been great to hear about Nu Quantum and we’ll definitely keep an eye out for news from the company and send any physicists looking for a job your way.
[00:20:00] Carmen: Thank you, Veronica. It’s been a pleasure.
Host Veronica Combs is a quantum tech editor, writer and PR professional. She manages public relations for quantum computing and tech clients as an account manager with HKA Marketing Communications, the #1 agency in quantum tech PR. You can find them on X, formerly known as Twitter, @HKA_PR. Veronica joined HKA from TechRepublic, where she was a senior writer. She has covered technology, healthcare and business strategy for more than 10 years. If you’d like to be on the podcast yourself, you can reach her on LinkedIn, Veronica Combs, or you can go to the HKA website and share your suggestion via the Contact Us page.
December 3, 2025
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