Better Qubits Through Material Science with Nathalie DeLeon

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In this episode we are joined by Nathalie DeLeon, Associate Professor of Electrical and Computer Engineering at Princeton University, who is well known for her research in color centers. Also known as diamond vacancies, these materials are a really fascinating platform for quantum information science and engineering applications. In todayā€™s episode, Nathalie shares her journey to become a professor and the winner of the Rolf Landauer and Charles H. Bennett Award in Quantum Computing.

Nathalie DeLeon Final

Sebastian Hassinger: [00:00:00] The new Quantum Era, a podcast by Sebastian Hassinger and Kevin Rowney.

Hello and welcome to another episode of the New Quantum Era. Uh, today we're gonna be having a conversation with Natalie Deleon, who is very well known for her research in color centers, also known as. As Diamond Vacancy, she's a, a professor at Princeton University. Um, these diamond vacancies are a really fascinating platform for quantum information science and engineering applications.

And Kevin, I, I was really struck by, you know, it was great. Natalie shared with us some of her background and her journey to [00:01:00] becoming, uh, you know, a quantum inform a quantum. Physicist, Um, and being in the field of quantum computing and as usual, everybody we've spoken to has a very, um, non determinant path to get to where she's

Kevin Rowney: gone.

A complex path. Yes. No, it really struck me how, um, vulnerable and humble she was about mean she Wow. She's now like a top of the, he a tenured professor at Princeton. Princeton. But you, it was, uh, our arduous journey, so, uh, impressive.

Sebastian Hassinger: That's right. Not only tenured professor, but also a recent, uh, award. The, um, American Physical Society, Ralph Landau and Charles M.

Bennett Award.

Kevin Rowney: Yeah. And that was, and our cool to science paper comparing all those different methods. I mean,

Sebastian Hassinger: pretty amazing. Yeah. He's done some great work and at some point we're at some future episode, we're gonna have to dig into Ralph Landau and Charles Bennett cuz they are, uh, seminal figures in the development of the field.

So, Um, that those names being associated with that award make it a pretty big deal. So, We'll, we'll, in this discussion, we'll learn more from Professor Dele about her work in [00:02:00] material science generally. Um, and as I said, with her background and how she, how she got to, how her career sort of developed and.

Also some recent, more recent, um, experimental, uh, use of tantalum for superconducting qubits in the place of more commonly used na opium, which is really interesting, interesting breakthroughs. Yeah, no doubt. Yeah. Terrific. So with no further ado, Here we go.

So we are [00:03:00] joined today. Uh, we have the distinct pleasure in having with us. Natalie Deion. Um, she's the associate professor of electrical and computer engineering at Princeton. Um, and the associate. Faculty in the Princeton Center for Complex Materials and very recently winner of the American Physical Society, Ralph, uh, Landauer and Charles, uh, Bennett Award.

So congratulations, Natalie, and thanks for joining us. Thank you. Um, would you mind starting just with a, a brief introduction and especially we're super, always super interested in hearing how people sort of found their way into the, the field of quantum technologies because it's, it's rarely a linear route.

is what we found. Um,

Nathalie DeLeon: yeah, sure. So, let's see. Well, the way that I would normally tell the story of my group is that, you know, we spent, uh, several years working on technology quantum technologies based on diamond. So we, uh, use NV centers in Diamond and we. [00:04:00] Discovered a couple of other color centers in Diamond and the ideas, you know, mostly to use them and things like quantum sensing and quantum communications networks.

And while we were doing that, uh, because what I like to do is orient my group towards a particular, let's say long term, hopefully not so long term technological goal. Uh, then what that requires you to do is solve a lot of problems at sort of. Different levels, right? You can't just live inside of device integration.

You sort of have to do device integration and think about new protocols and think about how you're going to integrate these different pieces together, like more of a systems architecture picture, but also drill down into the material side, you know, and say like, Well, what are the real problems? And what we kept on bumping into on both of those things was just, um, materials and surfaces were a real.

A real problem. Um, so then, so then, uh, after kind of drilling, accidentally becoming surface scientists in a variety of contexts, what [00:05:00] we discovered was that that was a playbook that's actually quite powerful. And then, and then I ended up working on super conducting QUTs just in the last, uh, couple of years because of basically from that vantage point advantage.

Um, So I, I think if you had asked me when I became a faculty member, if I was going to be working in quantum computing, I would've said no. Like you had said something mildly offensive. ,

Kevin Rowney: Well that's good.

Nathalie DeLeon: You know, like, uh oh no. Only crazy people would say that they're working on fall tolerant quantum computers.

Yeah, it was, yeah, . So, and, and, and I think that was probably true of actually quite a few people. Started their groups around, uh, that era, which was not that long ago. I've only been on faculty for six and a half years. Um, so, you know, I think, uh, I think people had a general sense that there are interesting things you can do with large quantum systems, but they would've sold their work as quantum mini body physics or, you know, uh, particular applications.

And I think it was still considered sort of a fool's errand to try to build a, a big quantum [00:06:00] computer. And obviously the world has changed really rapidly just in the last few. Um, so it, it is, it is funny that I'm like now very like, deep into the territory of, okay guys, what's it gonna take ? Like, how are we gonna make our first logical qubit?

Um, so that, that's been like a new trajectory.

Kevin Rowney: That's really interesting. I mean, was there, was there a key moment in your, um, uh, the, the landscape of what was happening that had you sort of get to a conversion towards, uh, towards being a believer? Or was it a gradual persua.

Nathalie DeLeon: I did not say I'm a believer.

Sebastian Hassinger: Ken, Ken Brown said to me, uh, every year they say it's impossible and every year the quality goes up by another order of magnitude. And so, you know, until somebody proves to me it's not possible, I'm just gonna keep plugging away. .

Nathalie DeLeon: Yeah. Yeah. I, I'm not sure. I'm just enough of a grumpy academic to not ever claim to be a true believer in anything, um,[00:07:00]

But, but I am, I am significantly more optimistic now than even maybe just like 18 months ago. You know, I think it, my, my perspective on this is shifting pretty rapidly. Um, and I, I think, uh, well, how do I put this? I guess there's, you know, there's a question of like, do you ever build something that you can do?

Shores I on and there, maybe I'm still skeptical.

Kevin Rowney: we're, we're a long way

Nathalie DeLeon: Yeah. . Yeah. But, um, but then, but then there's this other question of like, is there a lot of interesting stuff you can do with pretty, with pretty big systems before that? And, uh, and I think there, now I, I, I'm, maybe, I'm willing to say that I'm a true believer, that I think there are interesting things, you know, that there's, it's a rich space.


Sebastian Hassinger: it, is it fair to say that the promise you're seeing is sort of more aligned with like, Feynman's original, sort of the keynote in 81 saying, you know, that you can do, uh, uh, simulations of natural [00:08:00] systems, uh, that are quantum in nature, that you can't do by a classical means? If you can build a sufficiently powerful quantum

Nathalie DeLeon: system, I don't wanna get myself into too much trouble with my skepticism about quantum civilization,

Kevin Rowney: So we, we won't interrogate you. We were just looking for at least some, some nuance. Yeah.

Nathalie DeLeon: No, but yeah. Okay. So, so I think there's a, there's a few things that have sort of changed my mind about this, and a couple of them are serious points and one of them is maybe a little bit snarky. Um, so the, the serious point is that, Okay.

Uh, for a long time in terms of error correction, you know, we had like shores code or whatever, and it just seemed like, The resources were so high and the thresholds were so ridiculous that just nobody was ever going to be able to do that. And then there was, you know, the surface code and all of this topological stuff, and then that pushed the thresholds up a little bit.

Um, and then I, to me at least, and you know, I have a very naive, [00:09:00] not super expert perspective on these things. Um, I think the fact that people started playing around with really weird quantum computer. In the last 10 years, like, um, like this bo stuff, uh, that, that Rob Schoff and Steve Gr and Michelle Deborah have, have really pioneered, uh, it just opened up this creativity in like architecture and how you, how you think about these problems.

And then, you know, that busted open this biased noise stuff with air correction, where suddenly the thresholds were way different. Um, and it just feels like things are suddenly, you know, moving, moving very rapidly. And, you know, locally at, at Princeton, Full disclosure. This is my husband's work that I'm gonna talk about, But, um, great.

Sebastian Hassinger: So you can't trash it completely. .

Kevin Rowney: Yeah. .

Nathalie DeLeon: Yeah. Oh man. I have to hear about it constantly. Um, no, but it, it, it is very exciting. I mean, he pointed out something that is, is. Somewhat simple, but I think, you know, a lot of the most elegant [00:10:00] things are really simple, which is that, you know, in classical error correction, the best kind of error you can have is an erasure error where you just know that something is corrupted, um, and then you can just throw it out and replace it.

Uh, and, and he just pointed out that if you could do a quantum version of erasure correction, um, erasure conversion, You can actually get extremely high thresholds. So to me it just feels like all this stuff happened in such a short period of time, you know? And that, uh, if, if you had asked me like five or six years ago, I would've been deeply skeptical because I'm just like, Look, look at all these smart guys who haven't been able to move the

Sebastian Hassinger: needle on this.

Your point about creativity is a really powerful one. I think that, that, I feel like error correction is, is chief among the areas, but there are many areas within quantum computing where we won't know. The answer to the, these challenges won't be obvious until after the fact, right? I mean, we'll go like, Oh, of course it was that all along.

But it's gonna take this very, very open-ended creative [00:11:00] exploration of the space and openness to just a whole bunch of crazy ideas, . Um, because I mean, you know, it, we're, uh, we're on this side of, of an unknown discontinuous kind of breakthrough. And so, you know, nothing, everything looks possible, you know, it's plausible.

Nathalie DeLeon: Yeah, exactly. I mean, we should, we should be open to totally crazy architectures that don't look anything like classical computers. Right. And, and things that we're familiar

Kevin Rowney: with or, or even current precedent in quantum computing. Yeah. The challenge

Sebastian Hassinger: is the, is the rootedness in the architectures and the history of classical computing in a sense, cuz it's like just replicating what we did for classical definitely will not work.

And yet the whole industry and a large part of academia are still sort of anchored in those ideas in some.

Nathalie DeLeon: Right. Like people just feel good inside if you can just map it to silicon. Yeah. .

Sebastian Hassinger: Exactly. Exactly,

Kevin Rowney: exactly. So Natalie, we were doing a little, uh, tangent there on, you know, your perspectives of what led to your improved optimism, [00:12:00] so to speak, on, on quantum information processing.

Uh, but, but, but we, we maybe interrupted your, uh, description of your, your entry into the field. I, I just wanna make sure that, uh, we were all done hearing a little bit about your, your background biography before we move on to the rest of the. Oh yeah,

Nathalie DeLeon: sure. Um, so my, yeah, my entry into, uh, this field in science in general is like, probably pretty weird compared to a lot, a lot of people in the field.

So, uh, I was a chemist, uh, as an, as an undergrad. I was a spectroscopist working for Dick's there who had this, you know, amazing lab with all of these different kinds of spectroscopy. And the thing that I really learned from Dick is that he was just totally fearless about disciplinary boundaries. He didn't see it as, we're a group that does this, so you have to do this or we're not gonna do that because that's not what chemists are interested in.

But he just saw it as like, look, there's this problem. Let's just throw everything we

Kevin Rowney: have. We have skills, let's attack it.

Nathalie DeLeon: Yeah, yeah, yeah, yeah. And, and, and let's get new skills to attack, you know? And so, so that was really, that was [00:13:00] really cool, um, uh, environment to grow up in. And then, My PhD, I went to go work for Hun Park and my PhD is in chemical physics, which is sort of this like hybrid, um, you know, uh, uh, degree.

And, um, and Hunn had a very similar attitude. I mean, he, he did his PhD with Dick. So maybe all just comes from one, one family line or something. Uh, where he was also, you know, he didn't, he didn't necessarily see the world. We have to do this thing because it's what our group is good at. Um, but instead he was always sort of hunting for the interesting problems.

And there were sort of two formative experiences in Hunting's Group. One was that, uh, after he got tenure, which was like right before I joined, he decided that he wanted to become a neuroscientist. Just out of nowhere, um, and, and, and he went and, you know, shifted, uh, over the time that I was there.

Something like half of his effort towards a pretty serious biology lab. You know, like they have a. [00:14:00] They culture neurons, , they do a lot of stuff. Sounds fun. Yeah. Yeah. No, it was, it was very cool. Um, and then the other formative experience was that I joined his group to do a specific project, which was, uh, that I was working on electronic transport in one D systems and zero D systems.

So we were doing things like wiring up nano wires and uh, individual molecules, and then trying to use that as a tool. You know, look at specific intense matter phenomena and also as a tool for doing molecular spectroscopy. And you know, honestly, none of that stuff worked very well. The molecule stuff, it was a really tough project.

Kevin Rowney: Challenging area we've heard. Yeah.

Nathalie DeLeon: Yeah. Yes. And, uh, and Hun Kong was, you know, he had gotten really famous, basically inventing that technique. Like he was, he was the person who came up with this method for wiring up single molecules. And in my second year of grad school or something like that, or third, He decided, um, I don't wanna do these experiments anywhere.

I don't think they're going anywhere. I think it would be better for you if you didn't finish [00:15:00] your PhD doing the same thing. So we're just gonna cut it off. And I was the last person with a cold dilution refrigerator, in his group. And then, and then I was in the desert. For, uh, a year or two, um, you know, working on kind of random things and I didn't really know what the rest of my PhD would look like.

And, uh, I guess I have tenure now, so I can just say that's publicly, Hun Kong doesn't know all of these pieces, but I thought about dropping out of grad school and, um, you know, going, I, I had a, I had a latent interest. Policy and economics. So I thought maybe like, just go nurture that. Maybe

Kevin Rowney: you just go told

Nathalie DeLeon: tangent.

Yeah, right. Yeah. I, I even did some consulting work for a venture capital firm Oh, wow. And try, you know, tried to like, leave academia entirely. Um, all somewhat surreptitiously. And then, uh, but then eventually where I landed was we started working on, you know, Nanophotonics and Plasmonics. And then that took me to a, and that finished out my [00:16:00] PhD.

I was working on making these little resonators and I started collaborating with Misha Lukins group. And trying to do quantum optics experiments. And then, um, so that was my entry point to atomic physics and quantum optics. So I basically didn't do any of that stuff until I was like 26 . And then, and then that's the, that's the starting point for, um, Everything that I'm doing now.

See, I

Sebastian Hassinger: told you, everybody has a circuitous route to this. It's true,

Kevin Rowney: but it's a great, It's such a great story as well, Natalie, is that you lost to the desert for a little while. Now you're at the summit of Princeton, I mean, to your faculty. Wow. I mean, it's quite a journey. It's. Yeah, a lot. A lot of grad students get lost, you know?

I mean, Way to go .

Nathalie DeLeon: Yeah. Well I wouldn't recommend it to anyone cause it, it's not an easy place to be in. But I do, I do think. I emerged from it probably the same way that people emerged from getting lost in the woods, like they could outrun bears or something. . [00:17:00] That I made

Sebastian Hassinger: you stronger. Yeah, no doubt. Yeah,

Nathalie DeLeon: exactly.

Exactly. Like I, I, I sort of understood a little bit better how to pick problems and just how to think more broadly about problems. Right. Because it was the first time that I didn't have an advisor who just handed me a pre-baked thing. Like

Kevin Rowney: marching orders. Yeah, yeah,

Sebastian Hassinger: yeah,

Nathalie DeLeon: exactly.

Sebastian Hassinger: Hmm. That's interesting.

Nathalie DeLeon: It was a tough time, but it was an

Kevin Rowney: interesting time. Well, and thank you for sharing that with us. I mean, it's not, not an easy story maybe to remember , but

Sebastian Hassinger: Yeah, that's great. And, and so like circling back to what you were saying about error correction and even before that, where you were talking about sort of thinking about device integration and protocols and what are the real problems and materials is I, I'm just curious like.

You're, as I said, uh, you're sort of so far down in the stack, you're lower down in the stack in terms of materials and we typically, um, Kevin and I talk to people who are typically higher up. You know, they're building systems or they're building, um, software or they're exploring [00:18:00] algorithms. Um, how far up the stack does your, your sort of interest lie, and how does that inform what you're doing down at the materials?


Nathalie DeLeon: well, I guess, uh, I guess I started my exposition about why I'm optimistic by saying that I had three things to share so that, so I think I only did one of them. So, so the first serious point was that error correction is moving really rapidly. Uh, the second serious point is that, um, I heard a series of talks that I actually found really fascinating.

Uh, so, um, Al Christian Anda Kimani. Like going around talking about the fact that, you know, in some sense, fault tolerance is a phase transition is a quantum phase transition, right? That you have a different, you have a fundamentally different system before and after you turn on your error correction. And that's, that just really, you know, that's just amazing like, that just feels like now suddenly such a rich, fundamental physics field.

Uh, and then similarly umes [00:19:00] basani, uh, likes running around saying, You know, it's sort of an open question whether or not the universe really uses all of, all of Hilbert's space, right? Most, most things that we see are in like a very tiny fraction of Hilbert space. So in some sense, you know, you can sort of ask this fundamental question about whether or not, whether or not we really have all of this hilbert space.

By building a Paul Toler quantum computer, Right? Because there's no way for it to work without having explored all of those. So, so I feel like there's, you know, we're just barely scratching the surface of some of the really deep questions. Um, and, and it's interesting cuz all of these pieces have been in front of us all along, right?

Like we've, we've had, we've been able to think about them since, I don't know the nineties. But I think there's just, it's just you're in a really different world when people start building big systems. It's just a d. It's a different ecosystem and it makes people think about things differently. Okay.

Those are the two serious points. The snarky point is that, uh, I, I started sniffing around so. You [00:20:00] know, we did the stuff in NV centers where, um, we were really working on trying to make shallow NV centers, uh, with really long spin coherence times and you have all the surface noise. And, um, and the headline result was that we could do the surface processing to get about an order of magnitude or even two orders of magnitude extension in the spin.

Um, so my group now just does this for a living. Like we have. We can routinely make substrates that have like the only coherent she peace centers in the world. So we're just now doing, doing that all the time. Um, and I ran around giving that seminar saying like, Okay, here's how, here's how you did it.

And uh, and then people would come up to me. After my seminar and say like, Hey, do you want to try to solve anomalous heating and trapped ions or or, you know, in quantum dots we have all this weird charge noise that we don't understand. Why don't you come and help us figure out what the charge noise in quantum dots is?

And in super conducting qubits, you have all of this dialectic loss and [00:21:00] nobody knows where that dialectic loss of trauma. And I would always just demure and say like, I'm not gonna be like the sheriff that rolls into town, and, and cleans

Kevin Rowney: up some mess. .

Nathalie DeLeon: Yeah, exactly. And, and tells everyone how to fix their surfaces.

That is not my role in life. That's not how I wanna

Kevin Rowney: spend my time. Sounds like a hard job. Maybe thankless too. Yeah, I don't know. , .

Nathalie DeLeon: But then, uh, the way that I ended up getting kind of nerds, sniped into this topic. Was that we were, we were talking with a bunch of collaborators while we were forming our National Quantum Initiative Center.

So I'm part of the Code Design Center for Quantum Advantage with, together with Yale and IBM and Brookhaven National Lab and mit. Um, and, and, and many, many other partners. Uh, and I just started talking to the super conducting cubits guys and saying like, well, What have you tried? And then they would send me some papers and we kind of go back and forth.

And the snarky point is, I was like, Oh, they haven't tried anything. . [00:22:00] They have, they haven't, like it's all, it's all low hanging fruit. They've only tried, they've only tried like three superconductors, maybe four. Nobody has ever cleaned the surface. They've never even looked at what they have. So then I was like, Okay.

We can , we can, we can try this for a little bit. Maybe there's something

Kevin Rowney: you could do here. Yeah,

Sebastian Hassinger: yeah, yeah. Is that the genesis of sort of the, the, uh, the, the use of tum instead of naum is, Yeah. That's interesting. So Pat, Pat Goman was just telling me that story not too long ago, and it, it's a fascinating one, right?

It, it's, so, it has something to do with the, the number of oxides in NI is that,

Nathalie DeLeon: Yeah. Well, okay. Let me totally transparent about this story. So, uh, so it came out of an NSF grant and, you know, maybe this is a story about how NSF does great things. Um, but it was a total lark. Basically, a group of us were just like, Oh, we'll just put in for this random grant that it, that says that we're gonna look at new material systems and try to [00:23:00] clean surfaces, uh, of super conducting Cupids.

And, and just as, as evidence of how dumb we were, the team is, uh, Pat, uh, at, you know, at ibm. So he, we would have access to some devices. Uh, Victor Barr, who does STM at Wisconsin, Madison, uh, Bob Kava, who's a Salt State chemist, and that's a great team. I'm really happy with that. And then as an unfunded collaborator, we added Andrew Hu

So we were like, Oh, we don't really have to measure these things. , We can just try . Um, but anyway, so, so we had. We had our kickoff meeting, um, and the five of us were sitting in a room and we were like, Okay, Andrew, tell us what, you know, tell us what your qubits are made out of. And he showed us his material system.

And then, okay, my bias is. You guys haven't tried anything. I'm sure all your surfaces are covered in junk, so we're just gonna try to, to tackle that. Um, and you know, and maybe we'll try to strip off you black

Sebastian Hassinger: size. Gosh, where could the dialectric loss be coming from? . Yeah, [00:24:00] exactly.

Nathalie DeLeon: Exactly. Um, and then, and then Bob Kava, you know, came in and said, You know, I spent like a lot of the eighties.

Studying the oxides of na opium and na opium is a horrifically bad material system. You guys should definitely not be using that. Like opium will make different oxides if you just look at it funny. So there's no hope of controlling it. Um, so I think you should go one down on the periodic table to tamp.

That was basically the genesis . So it was, you know, he had, uh, he had some general heuristics that tanin should happen, nicer oxide because people had made. Capacitors out of it, you know, in the, in the micro electronics industry. But it was really just like, these oxides are terrible. These oxides are maybe better.

Like you should just try it. You guys don't try enough things. Um, and then the very first, and, and to tell you how little. We thought this was gonna work. Andrew handed this project to a new undergrad in his group, like a summer. A summer, [00:25:00] Go, go get some commercial films att. Let's just make a qubit outta of it.

And the very first qubit this guy made. Was the best Cuba Andrews group had ever made by an undergrad. Factor two. Yes.

So it was like higher, that enormous signal? Yeah. Well, no, actually Andrews sort of did the opposite, which was like, okay, now we, now things got serious , so now let's assemble like an actual team.

Sebastian Hassinger: That's

Kevin Rowney: a great story. It's a great story.

Sebastian Hassinger: Thank you for all that detail. Just to put a, a, a slight point on it, so the, the issue.

Now Obum, it's, it's that there are a whole bunch of different types of oxides that it forms, and each one would have slightly different electronic characteristics. Is that right?

Nathalie DeLeon: Okay, so I, I don't, I'm not willing to commit to what exactly is wrong with an iop cuz we haven't done super careful measurements.

But the general argument is, okay, you have all of these different psychometry, some of them are super conducting, some of them are insulating, some of them are kind of almost normal [00:26:00] metals. Um, and you just don't know what you have on your surface. And so you can have things. Quasi protocol loss and, you know, it's usually catastrophic to just spray a normal metal, the surface.

And then, and it's just very hard to, to characterize the dialectic loss. But what I'll say is, you know, since, since that work, um, I don't remember whose result. I think this is an iMac result. Like they've done things like take ni resonators on silicon, dip the entire thing in HF and stick it in the fridge as, as quickly as possible so that the oxides don't form back and they get quality factors that are comparable to what we get in tum.

Right. So it's not, it's not a problem with the underlying material

Sebastian Hassinger: system. It's, you can, you can either clean it or you can use a different material .

Kevin Rowney: Yeah, exactly. So, Natalie, if I could just chime in for a second. I mean, uh, we, we try to track these issues with, with some care. It's so interesting this, this detail.

It's just so fun. These anecdotes, I mean, help our audience understand because this theme keeps coming up in, in numerous interviews, not just you on the, the very [00:27:00] intense difficulty of, of surface physics right. And surface chemistry in, in this domain. Can you, can you, uh, perhaps unwind that for us a little bit for, for the audience?

I'm just, it, it feels as if it's a, it's a, a major challenge within the, the research.

Nathalie DeLeon: Yeah. Um, okay. So I think the story people would normally tell you about surfaces, which is not untrue, um, is that, you know, one surfaces are really hard because they're just difficult to control. Like controlling a bulk material is, um, you know, well, I would, I would say that bulk synthesis techniques are also not super easy, but that's usually something that, Upstream of you, like someone else has figured out.

So, so they either deliver something of some material or not, but then the surface you can screw up in a billion ways because you have to polish it or you're etching, or you know, doing all kinds of things. And then what exactly you're left with is, is. Extremely history dependent and therefore very complicated.

Um, so that, that, that's the first [00:28:00] part. Uh, and you know, most materials have to be different at the surface than the bulk. Um, not every single material, but most materials, like if you think about. Uh, diamond, which is near and endured my heart, it's carbon atoms all the way through the bulk. But then when you get to the surface, you now have these, you, it can't be carbon all the way cuz carbon has to form four bonds.

So it has to, it has to terminate with something. And then what exactly the surface looks like is sensitively dependent on what that termination is. If it's a mixture of things, you know, whether or not you've polished the surface correctly, all kinds of stuff. Um, the other problem that I think most people are aware of is that it's hard to look at surface.

So normally if you're doing, you know, spectroscopy, it's kind of easy to shine a laser at something and look at bulk absorption. You get a signal. Yes. Yeah, yeah. But the problem with a surface is that you're looking at this mono layer of atoms on top of an avogadro's number of atoms in the bulk. So like, how, how are you gonna pick out that signal?

Um, so there, there are a bunch of techniques that [00:29:00] people. Developed and won Nobel prizes for and things like that over the century. Um, and most of them involve taking advantage of the fact that some particle just doesn't, uh, travel very far in the surface. So you can do things like shoot x-rays and eject electrons, and then the electrons only have a mean free path of.

Let's say 10 nano. So the, so if you put some selection on the kinetic energy, then you can make sure that you're only looking at like the top few nanometers of material, that kind of thing. Um, Okay. But, but a lot of these techniques require things like ultra high vacuum, uh, or, or you have to go to a sync tron source.

So it's like not that easy. It's not that easy to build up surface science stuff in your lab. So I think that's another reason that people sort of shy away from it. Helpful background.

Kevin Rowney: Thank

Nathalie DeLeon: you. Yeah, but what I would say, so that's, I think that's like the standard picture. Um, but what, what I would say is the actual.

Problem with it. And I don't know if this is generic to everyone or if this is [00:30:00] just the quantum field. So maybe I should only talk about the quantum field cause it's the one that I know. Um, is that, is that I think a lot of people would like to just do AB testing, you know, so what they wanna do is try a thing and then say, Okay, we tried it.

And then we have this control, and then we look, you know, this thing has a longer lifetime than this thing. So it means that it worked. But the truth is that's, um, I mean, it's a very trivial point, but like losses. As like, you know, one over the quality factor, right? . So, so, so you can, you can change one thing, but if that's not the dominant thing, you're just not gonna see, you're not gonna see a delta.

So, you know, if you, if you do something, okay, like tantalum is a really good example. So we happen to see a really big delta cause the oxides are so bad. But actually getting from that first device to the like world record breaking device was a lot of pain because what you have to do, Um, make sure that your fab isn't introducing like very rough edges and kind of weird surface [00:31:00] morphology, and you have to clean the devices because if you just take your, you know, perfect metal that has these awesome properties and then deposit like 10 nanometers of hydrocarbons all over it, then all that you're measuring is those hydrocarbons then.

So basically you can kind of increase the ceiling with some new material system, but then actually revealing that that's the ceiling is, is quite difficult to.

Sebastian Hassinger: So, in other words, it's, it's sort of another iteration of the, you know, uh, 80% of the gain is 20% of the work, and the last 20% is 80% of the work

But getting that last bit is, is like mostly of the hard, hard stuff. Yeah.

Nathalie DeLeon: I mean, one of the analogies I found myself making actually just in subgroup meeting this morning, uh, is that it's a little bit like you're walking on a tight. And what you're trying to find is the higher tight rope to jump to, and there are a million ways to fall off of your tight rope , but that's not interesting.

Right. , That's not progress. Yeah. Yeah. That just flat on the ground. You haven't learned anything from that. Um, so it's [00:32:00] sort of a, it's a different, I guess it's a different mode of hypothesis testing than most people are used to for some

Sebastian Hassinger: reason. Interesting. You, you mentioned, um, uh, that diamond is, is near and dear to your heart.

I, I wonder is, is there a way to sort of, uh, describe, um, conceptually how, uh, how a vacancy in, in diamond can be used as a, as a two level system or for a cubit or, or as a sensing. Oh yeah, sure.

Nathalie DeLeon: Um, so the general, the general picture is really straightforward. It's just that, uh, Diamond has this very, very wide band gap.

It's five and a half ev, you know, this enormous window. And when you put defects into it, you tend to get very energetically deep defects, which means you get these really isolated electronic levels that are really, really far away from your band edges. Um, and it turns out that there's a bunch of these defects that just look.

Molecules. You know, if you, if you look at the electronic structure, it just looks like what you would get from group theory if you [00:33:00] added up all of those atomic orbitals. So you sort of don't have to think about the fact that you're sitting inside this extended lattice, but instead you, you know how something that looks like a little atom or a molecule with, you know, atom or molecular degrees of freedom.

So that means that you can do all of the same tricks that you pull in amo where. Can optically prepare the spin optically, read out the spin, um, you know, prepare super, uh, super physicians, coherent super physicians of spin states.

Kevin Rowney: I, I'm sorry, Natalie. A amo. Uh, could you, um, oh,

Nathalie DeLeon: sorry. Um, ATO Atomic molecular and optical Physics.

Thank you. Thank you. Okay. Yeah, it's you, you forget that, uh, people outside don't know all of the tribes. We try

Kevin Rowney: and track 'em all, but we don't have 'em all under perfect command .

Nathalie DeLeon: Um, yeah, no. So I mean, a lot of the people who work on color centers in Diamond, they come from that community, like people who would normally laser cool atoms and vacuum chambers, um, because it's a lot of the same techniques except you just don't have to laser cool.

You just have this thing sitting, uh, in, [00:34:00] in the diamond kind of for free. Um, so the idea, the general idea is that you use this spin. As your qubit degrees of freedom. Uh, and then you can just use all of the same tricks that people have from like a century of spin resonance techniques like NMR or esr, all these pulse sequences and everything.

Um, but then the, the really cool part about it is because you have this optical manifold of control, then you can also combine all of that spin resonance. With the last, I guess it's 30 to 40 years of single molecule imaging, right? People know how to make these microscopes that, uh, really focus down to the defraction limit and isolate a single molecule or single atom.

We have these amazing single photon detectors where you can, you know, you can detect really div signals. So the idea is that you, you, you use one of these microscopes to look at a single center, and then you use microwaves to manipulate the spin, and then now you have optical readout of your cub. Um, you know, and you're really [00:35:00] looking at, at a single qubit.

Uh, so, so, so that's sort of the, the general coolness, of, of color, of color centers and diamond. The part that's uncool is that because it is this atomic defect in the solid state, it's very hard to imagine how you're going to make large scale processors, right? Because now having controlled interactions between.

Dozens of NC centers or whatever, like they have to be tiled in some perfect way. You need, uh, you need to control their positions with extreme precision. Even if you could do that, there are some outstanding questions about how exactly you would do the architecture for individual addressability and things like that.

Uh, so I think, you know, I'm sure that I just pissed a lot of people off with this comment, but I think the

Kevin Rowney: real No, it's, it's helpful for us. And I, I don't mean them any, any animus, but I mean, uh, it does seem like it's very challenging to, to even a multi cubit architecture, let alone an advanced gate system that would, you know, run the entire, uh, qc.

Is that, is that correct?

Nathalie DeLeon: Yeah, I, I think, I think that's [00:36:00] correct. So, um, so I think the real killer apps are things like you can use them as sensors, right? So now, Absolutely. Now you have, you have this long lived qu. It's, it's sitting at a very particular place. Um, people have demonstrated really high magnetic field sensitivities that rival some of the best alternative technologies.

But then you're really in this like nano scale volume. So you can do things that look a lot like magnetic resonance imaging, but that, you know, inkstrom scales. So that that's, you know, one of the things that, that a lot of people are working on, the other killer app is quantum networks. Um, because you now can connect, spin and photon degrees of freedom and you're in the solid.

So you have the potential to integrate with integrated nanophotonics. Um, and, and that's why some of the most sophisticated demonstrations of, you know, long distance networks like this beautiful work that Ronald Hansen is doing at, at del, where they're, they tangle, you know, two NV centers that are a few kilometers apart, that kind of thing.

Um, you know, those are, those are built on color centers and diamond.

Sebastian Hassinger: So, totally naive question, [00:37:00] what, why is it called a color center?

Nathalie DeLeon: Oh, just because, uh, it looks colorful. Um, so if you , if you, if you Google search, uh, you know, just, um, like, Oh, they're beautiful images. Yeah. In Diamond, Yeah, you can, you can, you can do all of these Gemstar image images.

Sebastian Hassinger: So no, no connection with quantum chromo dynamics and in, in, um, In in the theory. Okay.

Nathalie DeLeon: Okay. No, this, this is, this is a very old term. You can find, uh, it, it's, it's this field that has been subsidized by de beers for a very long time, which is like, you know, do random spectroscopy and stuff in Diamond and, uh, and people have been characterizing color centers in Diamond for

Sebastian Hassinger: forever.

Very cool. That's such interesting little link to, to, uh, to gemology. Then I guess

Kevin Rowney: maybe given the time, it, this might be a good time to pivot towards the, your, your science paper and talk about that. It's, uh, possibly an adjacent topic. You have the scope of that paper included, um, color centers, but also a bunch of other fundamental, you know, [00:38:00] new, uh, material science foundations for quantum information process.

Um, I mean this, I I guess, what was the title? It was Materials, Challenges and Opportunities for Quantum Computing Hardware. Um, I mean, I'm wondering, is there, is there any way to give a, a decent, concise, um, overview of the, of the major findings there for our audience? Yeah,

Nathalie DeLeon: so huge topic. I get it. Maybe I can, Yeah, it's, it's, it's a huge enough topic that I think we got back a 27 page long review,

Oh, wow. Um, well, okay. May maybe, uh, maybe I can like, turn your question around a tiny bit and tell you a little bit more about like, the genesis of, of the review paper. So, so basically, David Soyer, who was at the Cavali Institute at the time, and now he's at I nq, um, sort of got this group together as part of a session, an invited session, ats that was like, you know, tell us about the material challenges and all of your, and all of your different platforms.

Um, and then, um, I don know [00:39:00] exactly how the sausage got made here, but basically a science editor got really interested in this topic and then asked exactly that group of people. You know, to, to put together a comprehensive review. Um, Sohan Pike at IBM was, you know, largely responsible for kinda keeping this group together and assembling it.

And essentially, you know, initially, uh, I said, Look, I'm about to have a baby. I can't, I can't do this. I can, I can do my little section on color centers because that will take me no time, but I'm not gonna participate in this general thing. And. That's fine. Give us your little center, your little section on color centers and sure enough, the little section on color center probably only took me a day and a half to write cause it's just my bread and butter.

Um, and then I came back out, uh, not exactly outta maternity leave. I think my kid was like two months old or something. And then I said, Okay, how's writing going? And they're like, We have not done anything . So, So then I, I, I actually got to rejoin this project. And then the kinda neat thing was that, uh, [00:40:00] that gave me an opportunity to shape a little bit what we were doing and, um, and what we sort of collectively decided was that one thing that would be really helpful for the community is to show your work.

Because in, in a, in a lot of these fields, there are all of these things that people say, you know, like, Oh, we know, we know that it's a real problem if you do. Uh, but then they don't say how they know it. And it, and it really turns out that it's just, Oh, because my advisor told me when I was a postdoc, like 10 years ago.

Right. Um, and, and you have no idea where that piece of information originated. So what it ended up turning into was that me as, as a, as an outsider still to super conducting qubits, you know, we had just started our tum work at the time, so I had a lot of interest, but I was definitely, I mean, I'm still not an expert, but I I was definitely not an.

Um, you know, honey, uh, you know, and, um, and Ben Palmer basically just let me [00:41:00] grill them on. Okay. You, you say that, you know that there's flex noise everywhere. How do you know that? And then we like drill down into the literature and, you know, produce this thing. So the thing that I'm really proud of in that, in that, Paper is that everything is backed up.

Everything is very solid and explains how do we know the things that we think we know. Um, so that, that was the main aim was here's the current understanding in each of these platforms, here's what people think and trap ions that leads to anomalous heating and you know, these problems that they see.

Here's the, here's the issue with quantum dots, right? But it specifically points to, and here's the experiment that somebody did that is. That shows us that this is a thing.

Sebastian Hassinger: Well, and it seems like there's an element of, of exactly what you said at the very beginning of, of sort of, uh, reaching up into the application, the intended application of the material to understand what the, the critical sort of characteristics and constraints are, and then feeding that back into the.[00:42:00]

The fundamental research into the materials and the, and the fabrication itself.

Nathalie DeLeon: Yeah. Yeah. That's right. I mean, none of these things make sense in a vacuum. You always have to connect them to some, you know, ultimate application. Yeah.

Kevin Rowney: But pretty interesting you did more of an exposition, right? Of the trade craft of each of these individual, uh, SubD domains.

Yeah. That's really cool. Yeah. I'm wondering, I mean, from, from this overview, uh, I mean, are you willing to make any daring, I don't know, projections or speculations of, of, of which, of the underlying platforms are Yeah. Nearing a breakthrough moment? Um, I mean, I know that's a, that's a gigantic, um, speculative guess I'm asking you to make, I still, I'm so curious to know your per.

Nathalie DeLeon: Yeah, it's, it's funny cuz it's especially treacherous from an internal politics standpoint

Kevin Rowney: because, Right. Well, I don't want you to get into that minefield, . No, no,

Nathalie DeLeon: I'm, I'm, I'm, I'm willing to wade into the minefield. Oh,

Kevin Rowney: good. Okay. I'll go in.

Nathalie DeLeon: Princeton is a pretty unique place in that we have all of these people who are working on quantum information in very different platforms.

You know, at a lot of, at a lot of [00:43:00] universities you'll have. One, one specific platform that's really strong and then not a lot of presence in others. But here we have super conducting qubits. We have color centers in Diamond, we have a quantum computers, we have quantum dots, we have mymon, we have, you know, quantum gas microscopes, we have molecules, we have electrons on helium.

Um, and one of the things, one of the things that's been really great about that is we all sit around and learn from each other, right? People have come up with new schemes for their platforms staring down the hall and saying like, Well, what is the superconducting ? Like, you know, what exactly are those guys doing?

Um, but then, but then the funny kind, uh, side effect of this is that we're constantly lobbying bombs and how what other people are doing is clearly not going work. So that my brain is just filled with what the best arguments against change platform was, or, or at least the starkest argument. So, Uh, you know, super conducting qubits are very cool, and I think we're gonna do really interesting things with them.

Um, the two [00:44:00] things that bother me right now are, uh, one that doesn't seem that fundamental, which is that they're really huge. Like are really gigantic. They're like the size of the human hair. It's really hard to imagine

Sebastian Hassinger: getting into, Right. A million of them. Yeah. Yeah. A

Kevin Rowney: million. They're like a millimeter in size, right?

You want

Nathalie DeLeon: Yeah. Um, but, but that's not fundamental. That is like a materials problem, right? If you could fix the materials, you could make them smaller. Um, but the other issue is like the connectivity is, is so, uh, you know, is so tough that you have to spend all of this time doing these swaps and then the swaps have to be made up of like C dots.

Like it's sort of like the worst possible way to, to move information around. Um, neutral atoms actually look pretty good. I. Jeff is gonna be really excited to hear me say this, . But that's, but that's, again, that's a platform that, uh, I remember just, let's see. I can always bookmark things by when my kids were born.

So this was Penny was was [00:45:00] one. So this would've been the end of 2019. I remember, you know, my postdoc advisor giving interviews where he was like, Oh, well we could just make a quantum computer out of neutral Adams. And thinking like, that's ridiculous. .

Sebastian Hassinger: Well, you said you, you spent some time with, uh, with Misha's group too, so I mean, they've, I mean, they've now spun out a commercial.

Yeah, yeah. That's what I'm talking about, right? Yeah, yeah, yeah. That's

Nathalie DeLeon: what I figured. You know, Misha was saying, We're making a, a programmable quantum computer, and I said, Misha, come on. You know, this is all really beautiful work, but I don't know if this is gonna be a quantum computer. I will totally say like, I will eat my hat.

Like it's, you know, it's only been, it's only been three years. My kid is just almost four. and now, like, they look like the biggest, baddest kids on the block. You know, they're doing beautiful things. It, it looks like there's this enormous ceiling on that technology, and I'm, I'm super bullish on, on neutral atoms.

Um, but then at the same time, at the same time, trap ions you have, um, well, trap iron are very slow. That's always the [00:46:00] problem. Um, but they're making logical qubits. I mean, that's amazing. , right? You, you would not, you wouldn't have. Just, just a year ago, if you said, Oh, we're gonna make a first logical cup in under a year, nobody would've said that.

Um, may, maybe I just painted a positive picture about everything. I meant to paint a negative picture about everything .

Kevin Rowney: No, but this is, it's really useful cuz it's an overwhelming, uh, amount of, uh, contrasting, uh, factors of advantages or disadvantages for the different technologies. So this is a useful context.

Sebastian Hassinger: Yeah, very, very. And uh, before I forget, I, I meant to mention or ask you, so at, you said, uh, trap s are slow, at least I've heard that that's one of the challenges with diamond, uh, vacancies as qubits is, is the slowness of being able to, uh, to sort of manipulate and read the state, Is that, is that.

Nathalie DeLeon: So at room temperature, this is always like a little bit hidden under the hood.

At room temperature, you get [00:47:00] extremely few photons per shot. So all of those beautiful, you know, coherent oscillation curves at room temperature, those are like millions of averages. Um, so the readout is actually quite difficult at low temperatures, though you have other, you have other possibilities. But the real problem, the real problem is the two cub.

That's the real issue. So, you know, you have to have dip attractions then, you know, how are you gonna tile this and, and make, how are you gonna do more than a single pair,

Sebastian Hassinger: basically. Right. Okay. And so, as you said, probably sensing initially until, and if we, uh, uh, sort of figure out those, those bigger problems,

Kevin Rowney: which I gather does not demand a multi gate, uh, you know, um, Yeah.

Nathalie DeLeon: Yeah. Well, and there's, and once you're, once you're not trying to build like a large scale quantum processor. There are other clever things you can do. Like if, if you wanted to make an entanglement enhanced sensor, you could take advantage of the fact that there are [00:48:00] all these little nuclear spins sitting around the NV center and then use those as this little quantum register.

Um, a lot of those, uh, protocols were really pioneered. For example, Lee J uh, who's now at University of Chicago, like wrote down the very elegant schemes for, for being able to take advantage of these

Sebastian Hassinger: s That's really cool. So I'm mindful of time, but I did want to mention and give you a chance to talk about the, the, the way that we met, which was over the, the Qri program.

The internship program that, um, Princeton and IBM do collaboratively. And I'm just wondering, You know, um, what your view is. Uh, I think programs like that are super important. Uh, and, and especially in terms of opening the aperture and, uh, for, for inclusion and diversity in this field. Um, you know, STEM does not hand and stem and, and the, the technology industries in general do not have.

Track record, uh, for diversity inclusion. Um, what's your [00:49:00] sort of view on, I mean, it feels like quantum as, as a forming field is an opportunity to maybe write some of those wrongs and do things a little bit differently. Are, are there things that you think either educators or industry, uh, uh, participants in this stage of quantum computing and quantum information technologies in general?

Can, can do to sort of help, uh, you know, make this one work better than the other fields have in the past. .

Nathalie DeLeon: Yeah. Um, well I don't know if I have any grand solutions, um, but I can speak to my. Specific experience through q r and other things. Um, I'm immensely proud of Q R. So, so the whole, I guess for people who have never heard of it, the whole idea is that the students spend, um, you know, it's a 12 week program and they spend six of those weeks at Princeton, uh, doing, you know, basically academic research, summer internship kind of stuff with one, one of the groups here, and then they spend six weeks at ibm.

Paired with a [00:50:00] mentor working on a project there. Uh, so, so the thing that, the reason that we started it was that I, in talking to kind of our undergrads, I realized that they really see their summers as this precious resource. And they were very stressed out about the fact that that meant that they had to choose.

Between, you know, academic work and industry work, and they wanted to be able to sample everything. So it, it was clear that there would be like a lot of demand for this kinda program. And then I think all of the art was in figuring out how to do it without making it be a shallow experience at both places, right?

Because six weeks is such an accelerated timeframe. Um, so. So the only way that you can do it is with a lot of intensive mentoring. So what we do is, uh, I mean it's, it's intensive mentoring paired with the fact that we select students that are pretty well prepared to begin with. That doesn't mean that they know anything about Quantum.

Um, it, it just means that they at least have had some research experience and are [00:51:00] academically excellent so that we know that they have the, the tools to be able to hit the ground running. Um, so sort of like the best possible cure applicant is somebody. You know, is awesome in a variety of ways. And then, uh, was like, I don't know, a plasma physicist or something, you know, and, and has, and has a paper and plasma.

Something's totally unrelated. And they're like, Well, I would really like to give this quantum thing a shot. Um, and uh, and that way, you know, we get to draw people, people into our field. Um, but basically what we do with them for on the faculty side is in the month or two before they show up at Princeton, we do things like directed reading.

Um, to get them, to get them up to speed and to really help them formulate, you know, what the project is going to look like here and pair them, you know, with students and postdocs who are going to be really responsible for, you know, training them in lab, um, or on the specific techniques. And I think that really active mentorship is just, Such a different [00:52:00] mode from, you know, normal summer programs are just like, Okay, show up in my lab and I'm gonna ignore you for the next three months.

Sebastian Hassinger: sink a swim. Yeah. Well, and it sounds like when you say mentorship, you also mean like a multi-party mentorship. There's a whole support mechanism built up around each cur participant, right? I mean, fellow students. Yeah, that's right. And yeah. Yeah. That's great.

Nathalie DeLeon: That's right. And, and, and they form a cohort that's very tight, like, uh, from what I've.

Um, even our first cohort in 2019, they're all still in touch with each other. When they, when they all applied to grad school together, they, you know, ask, Oh, what, you know, what are you guys doing? And, and, you know, still, still keep in touch with other, And then the other thing that we do while they're here is we have a bunch of, um, mentoring lunches.

So in addition, In addition to the stuff that's like, Okay, what are you gonna do for research And trying to keep, get them up to speed there. We just have them, you know, in a room with the other interns and one person, um, you know, one year like Steve came and I, I [00:53:00] really just wanted to like sit through.

That thing cuz I wanted to hear what Steve actually say. Yeah,

Sebastian Hassinger: we just talked to Steve last week. , ok. Yeah.

Nathalie DeLeon: But I, you know, but I left the room so that they could ask all of their questions without feeling self-conscious. And then they, and they get to hear all of these people's individual stories and, you know, you know, ask the tough questions about like, how do you pick a research program and how did you get into this?

Um, and the, the thing that I'm maybe most proud of, Locally is that I had this amazing student, just like, incredible student. And um, and he was just like a, you know, I won't even go into all the details of how he was such a powerhouse, but he was just such a powerhouse. He's way smarter than I am. And he showed up, solved all this stuff, cracked open this program, like this whole thing that's turned into this whole research program in my group.

And then at the end of the summer gave me one of the best compliments I've ever been given, which is that he said, uh, you know, this was so. Um, working with you has, you know, on this project has been so inspiring and has given me [00:54:00] the confidence that I could totally do this. And I'm like, How did you not

Sebastian Hassinger: have this

Nathalie DeLeon: Like, you're obviously amazing, but I think he had just never, he had never, you know, had close enough mentorship to finish a. Or something like he had never gotten to, to that stage where you're like, Oh, that's what it looks like to do a science.

Kevin Rowney: Right. And that, and that can be so rare in these academic programs.

I mean, decent guidance and mentorship, right? I mean, often enough it is kind of a sink or swim thing. So yeah, it's it's amazing program. Really. Yeah. .

Sebastian Hassinger: That's awesome. Well, that's terrific. Um, thank you so much for your time, Natalie, anything, anything you'd like to end off on? Anything we didn't catch, uh, in our agenda, in our

Nathalie DeLeon: conversation?

Oh gosh. I think I already got myself into enough trouble.

Sebastian Hassinger: we can give you final edit if you need it. . No, I think, I think it's all been fairly, fairly ta. Who knows . But yeah, [00:55:00] this has been terrific. Um, it's been super, super fun talking with you and really, really interesting. So

Kevin Rowney: grateful for your time. Really. Thank

Nathalie DeLeon: you. Thank you so much. It was a lot of fun.

Kevin Rowney: Okay. That was, that was so fun. I, I tell you, you know what really stood out for me? It was, there was [00:56:00] a, a quote from Wolfgang Paul that was, uh, mentioned in our last interview with, with Steve Gervin. That, that I thought was so apropo, this, this whole discussion, right? It's great quote. It goes, God, Made the bulk, uh, but the surface was invented by the devil,

And it just seems like that's such a tough frontier for many of these Absolutely. The outcomes for these experimental apparatuses. And, you know, that that big breakthrough, her group pioneered with tantalum. I, I think really, uh, underlines, underlies that same quote. So

Sebastian Hassinger: Absolutely. And also just bringing that.

Type of deep understanding of, uh, of surfaces, of, of materials and how they, how they are deposited, how they interact with one another. You know, it seemed like bringing a materials perspective to, uh, to the quantum science and engineering. Um, conversation had some, some extremely low hanging fruit. I mean, she said, you know, there, there hadn't been a lot of experimentation at the material level and there hadn't been a.

Of, uh, you know, honing of the techniques to clean and prepare [00:57:00] surfaces. So, uh, I think that there's really exciting possibilities in, in, uh, immediate gains for, uh, applying from applying, uh, Professor Dion's sort of perspective here. No doubt. Yeah. Pretty

Kevin Rowney: cool. I think it was also just, uh, so cool to hear how the, the, the Princeton team, it's got this, uh, huge diversity in different research, uh, avenues pioneered by different principle investigators for various different platforms for the ceo, quantum information science, uh, technologies.

And so they're able to, you know, and up. A friendly academic way, uh, you know, compete and, and compare and contrast these different technologies and debate about what's going on, what are the problems and how they can get beyond. So very, very interesting department over there. There's clearly, clearly poise for , yet more big

Sebastian Hassinger: breakthroughs.

Absolutely. And that type of diversity of thought is probably one of the most crucial ingredients for finding the path forward for quantum information science and engineering as a, as a field, because, uh, [00:58:00] certainly nobody has all the answers today. So, as, as broad, uh, uh, a field of inquiry as possible seems like the only rational strategy to me,

Kevin Rowney: Well, well, thanks again to, to Natalie, uh, for your time. I know it's very precious and, uh, wow. That was really fun. Thank you so much. Yeah,

Nathalie DeLeon: thank you. Until next time.

Kevin Rowney: Okay. That's it for this episode of the New Quantum Era, a podcast by Sebastian Hassinger and Kevin Rooney. Our cool theme music was composed and played by Omar Costa Ha.

Production work is done by our wonderful team over at pod. If you are at all like us and enjoy this rich, deep and interesting topic, please subscribe to our podcast on whichever platform you may stream from and even consider if you like what you've heard today, reviewing us on iTune. And or mentioning us on your preferred social media [00:59:00] platforms.

We're just trying to get the word out on this fascinating topic and would really appreciate your help spreading the word and building community. Thank you so much for your time.

Creators and Guests

Sebastian HassingeršŸŒ»
Sebastian HassingeršŸŒ»
Business development #QuantumComputing @AWScloud Opinions mine, he/him.
Nathalie De Leon
Nathalie De Leon
Associate Professor of Electrical and Computer Engineering, Princeton University
Omar Costa Hamido
Omar Costa Hamido
OCH is a performer, composer, and technologist, working primarily in multimedia and improvisation. His current research is on quantum computing and music composition, telematics, and multimedia. He is passionate about emerging technology, cinema, teaching, and performing new works. He earned his PhD in Integrated Composition, Improvisation and Technology at University of California, Irvine with his research project Adventures in Quantumland ( He also earned his MA in Music Theory and Composition at ESMAE-IPP Portugal with his research on the relations between music and painting. In recent years, his work has been recognized with grants and awards from MSCA, Fulbright, FundaĆ§Ć£o para a CiĆŖncia e a Tecnologia, Medici, Beall Center for Art+Technology, and IBM.
Better Qubits Through Material Science with Nathalie DeLeon
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