The New Quantum Era

Introduction:
In this milestone 50th episode of The New Quantum Era, your host Sebastian Hassinger welcomes Dr. Anna Grassellino, a leading figure in quantum information science and the director of the Superconducting Quantum Materials and Systems Center at Fermilab, or SQMS. Dr. Grassellino discusses the center’s mission to advance quantum computing and quantum sensing through innovations in superconducting materials and devices. The conversation explores the intersection of quantum hardware development, high energy physics applications, and the collaborative efforts driving progress in the field. We recorded our conversation at the APS 2025 Global Summit with assistance from the American Physical Society and from Quantum Machines, Inc. 

Main Topics Discussed:
  • The vision and mission of the Superconducting Quantum Materials and Systems (SQMS) Center, including its role in the Department of Energy’s National Quantum Initiative and its focus on developing quantum systems with superior performance for scientific and technological applications.
  • Advances in superconducting quantum hardware, particularly the use of high-quality superconducting radio frequency (SRF) cavities and their integration with two-dimensional superconducting circuits to enhance qubit coherence and scalability.
  • Key technical challenges in scaling up quantum systems, such as mitigating decoherence, improving materials, and developing large-scale cryogenic platforms for quantum experiments.
  • The importance of interdisciplinary collaboration between quantum engineers, materials scientists, and high energy physicists to achieve breakthroughs in quantum technology.
  • Future directions for the SQMS Center, including the pursuit of quantum advantage in high energy physics algorithms, quantum sensing, and the development of robust error correction strategies.
Notable Papers from Fermi’s SQMS Center:

Creators and Guests

Host
Sebastian Hassinger
Business development #QuantumComputing @AWScloud Opinions mine, he/him.
Guest
Anna Grassellino
Director of the National Quantum Information Science SQMS Center, a Fermilab Senior Scientist and the head of the Fermilab SQMS division
Producer
Ayann Ettienne McGuire

What is The New Quantum Era?

Your host, Sebastian Hassinger, interviews brilliant research scientists, software developers, engineers and others actively exploring the possibilities of our new quantum era. We will cover topics in quantum computing, networking and sensing, focusing on hardware, algorithms and general theory. The show aims for accessibility - Sebastian is not a physicist - and we'll try to provide context for the terminology and glimpses at the fascinating history of this new field as it evolves in real time.

Sebastian Hassinger:

Anna, thank you very much for joining me.

Anna Grasselino:

Thank you for having me.

Sebastian Hassinger:

That's great. So, we're here at APS. I saw your session yesterday, that was part of the NQI, centers for a retrospective. And I thought it was really interesting. I thought really what distinguish your presentation was a very, intense focus on increasing coherence times.

Sebastian Hassinger:

That's clear from the results you've gotten at SQMS. But like, tell me a little bit about, it's sort of a multipronged strategy to examine a number of different ways to, to, attack that challenge, right?

Anna Grasselino:

Yes. It's been a really exciting journey. We really put together a coalition of experts at three sixty degrees, to attack decoherence in superconducting devices and superconducting qubits. Like you say, it's a multi pronged strategy. We built the center around the fact that actually myself, my background, what, and I think that's really what's important to be an effective director.

Anna Grasselino:

I think you have to be excited about the mission of your I spent half of my career actually doing that, pushing coherence, the quality factor of cavities, making them how do we make superconducting cavities as efficient as possible, less loss, where are these losses coming from?

Sebastian Hassinger:

And that was in the, in the context of, of, particle acceleration. Right.

Anna Grasselino:

I mean,

Sebastian Hassinger:

that was the okay, great.

Anna Grasselino:

Exactly. For particle acceleration. And actually we built actually, an entire light source at, Slack, at Stanford with our technology where we pushed the coherence, the quality factor, factor three, with in fact some very tweak, some very small subtle tweaks in the impurity concentration in the first, let's say, 100 nanometers of the surface of these devices. And so in a similar way here, we have adopted this approach of hand in hand the material science, the nanostructure, the superconducting properties. How do they tie?

Anna Grasselino:

Can we push for a really fundamental understanding of how they tie to the device performance? The multi pronged approach you were mentioning, to me what works always best is you must push to do novel processes, novel things. Sometimes you are right about what you're trying to get and sometimes you get something completely different, but that's how science works. When you studied in detail and you develop a novel understanding that then guides really, the performance in a systematic way. And so our approach at SQMS has been, as I explained in my presentation on Monday, we have created several task forces and cross cutting groups across the center.

Anna Grasselino:

One that I'm particularly proud of, for example, this National Nanofabrication Task Force, where we've got experts from industry, from research foundries, and they work really hand in hand. And they look at changing processes when we fabricate these devices by changing one variable at a time, if possible, for example. And then hand in hand with the materials task force, where once we make a new device, then it goes and it gets reviewed by experts in a variety of techniques, surface analysis techniques from the most conventional SEM and TM, and taking these techniques down to cryogenic temperatures. I think this has been a very important point, not studying just with microscope, but at the temperature, at

Sebastian Hassinger:

the operating temperatures.

Anna Grasselino:

And then really also looking with things that are a little more exotic techniques, including muon spin rotation, atherosclerosis. So, And we have gained a lot of novel insights. And then feeding all this knowledge back into how we fabricate, how we move forward with the next steps.

Sebastian Hassinger:

You mentioned sort of degree of collaboration across industry as well. I know Rigetti in particular, mean a number of industry partners are active at SQMS, but Rigetti has really been integrating a lot of your findings in their own design and fabrication, right? It's almost a partnership more than a collaboration. Like they've been getting direct sort of value out of that relationship it seems.

Anna Grasselino:

Yes, I think for me this has been maybe one of the most successful things. So when we went into this initiative, I guess one question and the initiative of this center is really bringing together national labs, academia, and industry to move forward together. But has always been a question mark, how much will industry be open, right, with all the questions around IP, right? But I think Rigetti has been a super successful collaboration model where we have been really open with each other. They've been really open with us, with our SQMS partners.

Anna Grasselino:

That's key. That's essential to really then being able to make progress together. But yes, so some examples include so for example, the studies on encapsulation where we understood that the surface oxides were very lossy, and we wanted to replace niobium oxides with less lossy oxides, such for example, as tantalum or gold or other type of encapsulation strategies. So we did it first at Fermilab at the University of Chicago Pritzker nanofabrication facilities. And then when we saw the success, we repeated in the commercial foundries at Rigetti.

Anna Grasselino:

They saw actually the same successful doubling of coherence times on their silicon based qubits, which for us was really fantastic success to see, indeed, that it reproduces in the commercial settings. Other things included, for example, some chemical different chemical processing of the silicon surface. This was in collaboration between Tigere and our Northwestern partners, where Professor Marcus has been leading how we passivate silicon to create a less lossy silicon oxide. And these findings have been implemented, actually, in Rigetti processes. The ABA, the annealing of the junctions that Dave Papas has been leading at Rigetti, for example, which gave more systematic, really much more systematic, performance of these junctions.

Anna Grasselino:

This was also a very strong collaboration with AIMS Lab, where AIMS was leading the characterization and really understanding of what this novel treatment is actually doing on a nanostructure level. So there are numerous examples of where really we have been successfully working together and integrating things directly into their processors.

Sebastian Hassinger:

And and a lot of that has to do with, Transmon, you know, designed superconducting QSP. You've also done a lot of work at SQMS on, ultra high q, superconducting radio frequency cavities, right, which are more, I guess, derived from those call the super colliders, like the the equipment that you would need for that type of use case. Is there what's the applicability of those cavities, those devices to, to, either quantum computing or quantum networking, quantum memories, that type of application?

Anna Grasselino:

Thank you for asking. Yeah. So this was actually in fact the central theme. And then I think everybody got very excited about the materials and the transmit cubits. So a lot of effort actually went into that.

Anna Grasselino:

But really the thing that we said, again, going back to these initiatives are only successful, I think if you build it on who you really are and what your strengths are. So we viewed ourselves at Fermilab as the place where we make the best cavities in the world. I mean, without exaggeration, we've been able before the center started, we demonstrated the, niobium three-dimensional resonators with coherence times of two seconds in the quantum So this was very exciting.

Sebastian Hassinger:

That's two seconds, not milliseconds, not microseconds.

Anna Grasselino:

Exactly. Whole seconds. So then the the idea is to pursue this cavity. So this is for empty cavities, right? Now you want to turn into an actual quantum device, so you have to non linearize it.

Anna Grasselino:

So you have to couple it with some element that adds the nonlinearity. So the idea here is to really couple cavities and transmog qubits. It doesn't have to be a transmog qubit, could be something else, but currently that's what we are doing. And then you turn this structure into an actual QDET. So the idea is to actually build D levels.

Anna Grasselino:

And that is only possible because of the very high coherence of the So five years down the and that ties it together with the theme of improving the transplant because ultimately, if the Transmon can become the bottleneck dragging down the overall coherence of the combined system. So really, that's how the center come together cohesively. We improve the Transmon for helping the community, for helping industry, for chip based architectures. But at the same time, it's the Ansila for the architecture that we want to drive for quantum computers. And so four and onetwo years down the road, I think we're very excited of the recent results that we showed.

Anna Grasselino:

We have demonstrated a double cell. So this is Alice and Bob talking to each other with the first gate fidelity that we quote, 99.8%. And we are able to build very large fog states above 30 fog states with still with coherence of milliseconds. So that's a really exciting thing. So we think that there is a lot more research to do where we, for example, could expand and package more modes into the structures.

Anna Grasselino:

So we think, you know, when people think about these cavities, they see them as large, bulky,

Sebastian Hassinger:

you know,

Anna Grasselino:

do they really scale? But actually the scalability is in the coherence, is in the back.

Sebastian Hassinger:

And the multiple states within the one cavity.

Anna Grasselino:

Within the one structure. Exactly. Exactly.

Sebastian Hassinger:

Does that make it more conducive to to say memory or networking applications?

Anna Grasselino:

So that could also be we have not explored the angle of using cavities as in the repeaters, but that can also absolutely be a very important application. So we are very focused on building an actual quantum computing

Sebastian Hassinger:

Right.

Anna Grasselino:

Prototype that is based on these cavities. But, yes, the memory part is also Right. An important, application that we will perhaps explore in the future.

Sebastian Hassinger:

That's cool. And, I mean, everything that you're describing, of course, there's there is experiments, there is efforts, is innovation that you are describing that is directly carried out by people at SQMS, partners with SQMS, but in addition the National Labs are an incredible sort of investment in infrastructure for the scientific community and that the NQI centers feel like they're extending that to infrastructure for the quantum computing or the emerging technology around quantum science and technology community. The example I'm thinking of is the quantum garage. You're building resources and infrastructure that are helping anybody working in the quantum community, really. Can you tell me more about that garage?

Anna Grasselino:

Yes. Thank you for actually looking through all the details. Of course. Absolutely.

Sebastian Hassinger:

I didn't do it just over the last couple of days. I've been watching what you've been doing at SQMS for years now.

Anna Grasselino:

You. Absolutely. We view these, you know, of course we are excited. So that's the number one. We want to push the technology, but it is a service to the field.

Anna Grasselino:

It's a service to the And of course it is also a little bit selfish because we do want to use these tools to discover new physics, right? I mean, that's an important motor I do want to mention. We do have a lot of, part of when we built the center was the excitement across from the theory division, you know, from the particle physics division. These are going to be novel tools that will help us advance our mission of understanding the universe at a smaller But yes, back to the service of the community. The idea of the garage was, first of all, to advance all the goals simply needed to be able to have more throughput.

Anna Grasselino:

And so we added a fleet of six dilution fridges, which though we do make and now we make available to the community. Again, not open very, very in a very open way to the community in SQMS. But we, of course, also say that if people see value in the special tools that we have, there can be cavities to measure let me just give an example. Part of the things that we deployed at the garage is using a set of cavities also as novel tools to characterize dielectrics, like the substrates, for example, with parts per billion precision. Because these cavities are very, very high quality factors, you can actually use them as sample hosts.

Anna Grasselino:

And so places like Kyocera that makes substrates like Sapphire and other type of substrates for quantum computing chips, they've come to us for helping them characterize their substrates. That's an example where they weren't part of SQMS, but they saw a unique tool in what we offered at the garage. And there was definitely bidirectional value there, because together we can push. And substrates, low loss dielectrics continues to be a really, really important topic for pushing further coherence of superconducting qubits. So that's just an example.

Anna Grasselino:

We have had startups that wanted to test their control hardware, and we have a little QPU that we co developed with Rigetti, a nine chip one, And they can come and hook up their hardware. There are some areas where we see value in helping beyond our partners. One area where I really see the national labs, like Fermilab, shine in terms of service to the community and helping advance critical technologies for quantum is the cryogenics. So that's actually even beyond the garage. But as you may know, Fermilab has really huge facilities in terms of low temperature cryogenics.

Anna Grasselino:

We have cryoplants that are just sitting around that were used for some experiments. But the experiments now are finished, and so they are available. So there is a huge amount of expertise in cryogenics and ultra low temperature cryogenics. So part of what we are doing, for example, is taking this expertise, taking these facilities and putting it to the advancement of ultra low temperature technologies for future large scale data centers. So one of the things that really excites us, for example, is our recent partnership with Maybell.

Sebastian Hassinger:

Right.

Anna Grasselino:

They are wonderful company that is growing in The US in this space.

Sebastian Hassinger:

And it's good to see more fridge manufacturers coming out.

Anna Grasselino:

Exactly. And so,

Sebastian Hassinger:

as you said, eventually we're going to be filling data centers with these things. It's, we need a lot of people building them.

Anna Grasselino:

And so they're a critical, a critical technological obstacle is when you need to move to a farm of, let's say, 50 to hundred fridges, a, it becomes, from the point of your power consumption, it becomes economically really disadvantageous. Right. Unless you actually directly connect to a liquid helium cryoplant. And so this work of liquid helium cryoplant to millikelvin has been something that we have done research on at Fermiab. And so with Maybell, we plan to actually now work together to bring this technology that we have advanced to become a commercial reality here in The US.

Sebastian Hassinger:

I guess that's I hadn't thought of that. The dilution refrigerator is really designed from the ground up to be almost a standalone experiment, not a deployed technology. So once you deploy it in in mass, in in in a data center, you're gonna have to think about your cooling infrastructure as a whole facility, not as a standalone. Correct. That makes total sense.

Anna Grasselino:

When when you want it I mean, it's great that they are standalone. It makes a it makes it brings the ability to do this type of experiments in a basement or university. So that's great. But like you say, the data centers are going to be something completely different. So that's something, again, where now we are discussing to bring, for example, pharma fridges to do a validation of these technologies, for example, at Fermilab.

Anna Grasselino:

So maybe I could bring a fleet, for So just in answer to your question where national labs can shine, I mean, this is kind of who we are. Large scale facilities, system integration on a very large scale. It's our bread and butter going back to who we are. We build accelerators on kilometer scale. We describe distribution systems that span kilometers or so.

Sebastian Hassinger:

Well it's so interesting, I mean I think one of the unique sort of characteristics of this point in time is that you have all that sort of big science experience and infrastructure as the national labs and those types of that scale of investments in basic science is really the public domain. Right? It's for the public good. It's it's driven by the public sector. But in this instance, we've got also the private industry, private sector, you know, looking at seeing this as being a technology with incredible applications in the future.

Sebastian Hassinger:

So you're really, you know, leveraging science infrastructure to bootstrap early stages of a of a new technology. I think that's really, we haven't seen that in many decades, I think, in this way. So that I find super, super interesting and and why I find the the DOE DOE in in Kauai Center so fascinating. You you're sort of at this point where you're, you know, the the the Monday session was almost a retrospective of what you've accomplished over the last five years because there is this NQI reauthorization upcoming and the the centers are sort of having a chance to go back to their proposals and and think about the next five years. So what do you see as being the in five years time, what do you wanna look back on and and and see that you've accomplished at that point?

Anna Grasselino:

Yeah. Thank you for the question. No. No. First of all, yes.

Anna Grasselino:

I think the Monday session really offered us an opportunity of taking a breath and looking back, we definitely accomplished a lot. I think there was a question at the end of the session, which was, are we doing everything? Is there something we are missing? And I think it goes a little bit along what you are saying now. So five years down the road, looking back, what is really important?

Anna Grasselino:

And I answered on Monday saying, and I will say again today, there is definitely strong push and appetite to move to systems. We spent a lot of time in the first five years really attacking, at least at SQMS, attacking the coherence. And I think this is really it continues to be really important. And I actually think it will be dangerous if we say, oh, that's all taken care of. It's solved.

Anna Grasselino:

It's not a problem. I think sweeping things under the carpet will always come back and bite us. So that needs to continue. Attacking negligence will simplify our life in terms of how large the systems are going to have to be. But it's true that we must build systems.

Anna Grasselino:

We cannot continue to focus only on the fundamental science aspect. I think the NQI reauthorization has explicit language now pushed towards engineering systems and applications. So again, the real challenge now is going to be balancing those things, in my opinion. We do want to build a system. So if we take the cavity results, I think we feel now that we have some solid building blocks that we can start to scale up.

Anna Grasselino:

Of course, you know, everybody wants to like make it even better. Oh, but is this the perfect building block before we build a prototype that is, let's say, hundred qubits? And so that's where I'm pushing our group to say, everybody starts from somewhere. Right. It won't be our first, you know, mid scale prototype won't be perfect, but we have to do it.

Sebastian Hassinger:

Yeah. In the startup plan, we call that an MVP.

Anna Grasselino:

So, so that's the way I view it. So we want to really build our first midscale prototype, continue the research on the fundamental science, aspect of decoherence, continue the research at the building block that will, you know if we you know, right now we have a double cell, but

Sebastian Hassinger:

Right.

Anna Grasselino:

We will be able perhaps to have to package even many more modes.

Sebastian Hassinger:

Well, and imagine you're gonna need a specialized tool chain for even programming something with a hundred QDits. Right? I mean, that's not just a a that's that's different than just addressing a number of qubits with two levels each. That's a a totally different type of of programming, it sounds like.

Anna Grasselino:

Exactly. Yeah. And so we are exploring I won't say everything, but we are exploring exciting partnerships also with some new industry partners in that space. So I think it's really, it's coming together that, you know, we started strong, but we are now really growing and being more and more integrated across the ecosystem. And, I'm excited to extend those partnerships with various main industry players.

Anna Grasselino:

And one of them is IBM.

Sebastian Hassinger:

Yeah.

Anna Grasselino:

So with IBM, we are very excited to work together on building larger systems.

Sebastian Hassinger:

So that's gonna be CyQuantum and there's a I mean, the you you you have the benefit of being in the middle of the Illinois sort of quantum explosion that's going on. Right.

Anna Grasselino:

I mean, Illinois is really incredible. It's incredible. We were so thankful that governor Pritzker came to the inauguration of our garage. It, it's, it's nice to know that, you know, even on the political level you get so much support and generally quantum gets really strong bipartisan support all around. So this is really great.

Sebastian Hassinger:

Yeah. That's fantastic. Thank you so much, Anna. This has been really great. I very much look forward to the next five years of SQMS.

Sebastian Hassinger:

So

Anna Grasselino:

Well, thank you very much for your kind words, and we are excited to come back here in five years and tell you even more exciting stories.

Sebastian Hassinger:

Excellent. Thank you.

Anna Grasselino:

Thank you.