Quantum Computing and Chemistry--Dr. Kade Head-Marsden, Univ. of Minnesota

Quantum computing promises to supercharge scientific research with its ability to solve multiple problems all at once. It could lead to more rapid development of drugs and materials to improve the way we live. But first, there are some serious bugs that have to be overcome.  Dr. Kade Head-Marsden, a chemist at the University of Minnesota, who uses quantum computers to study molecules, lays it all out for us; what is quantum computing, how will it help us, what are the promises and pitfalls.  Her presentation, excerpted from a live talk sponsored by Telluride Science, was moderated by veteran broadcast journalists Judy Muller and George Lewis.

Transcript

Science Straight Up

Season 6, Episode 7

Dr. Kade Head-Marsden—University of Minnesota

“Quantum Computing and Chemistry”

Moderators: Judy Muller and George Lewis

(theme music—establish and under)

GEORGE: From Telluride Science, this is “Science Straight up”

JUDY: And on this episode….

KADE: Our first question is, what is quantum computing? What do we mean when we say a quantum computer? Why is there so much focus on chemistry? Does chemistry need to be remade? Does it need to be revolutionized? Why is this such a focus in this area?

GEORGE: Okay, that’s six questions. But we’re gonna cut her some slack.

JUDY: Dr. Kade Head-Marsden is an assistant professor of chemistry at the University of Minnesota. She leads a group of scientists focused on how the emerging field of quantum computing might help us better understand the behavior of molecules in chemistry.

GEORGE: Quantum computing is just beginning to take its first baby steps. And there are a lot of bugs to overcome. But classic computers can’t do everything that chemists want in order to detect and model the way those molecules do their thing.

(crowd noise)

JUDY: She participated in this year’s science workshops put on by Telluride Science where leading scientists from all over the world gather in a “think-tank” setting to exchange and debate ideas. She was asked to tell folks from the local community about her work in one of the “Town Talks” presented by Telluride Science.

KADE: So, I wanna talk today about quantum computing. And to do so I'm going to introduce some topics, but what I wanna start with is going back in time a little bit, so only three to six years, but in quantum computing time that is feels like several decades.

GEORGE: She pops up a bunch of old news headlines on the screen about how quantum computing was going to supercharge her field…chemistry…things like “Chemistry: Quantum Computing’s Killer App” “How Quantum Computing Can Revolutionize Chemistry” “Quantum Computing, possibilities without end.”

 But, she wanted to cut through the hype.

KADE: So, in these headlines, again, our first question is, what is quantum computing? What do we mean when we say a quantum computer? Why is there so much focus on chemistry? Does chemistry need to be remade? Does it need to be revolutionized? Why is this such a focus in this area? And then, importantly, what can we actually take from all of this? And so again, a lot of this enthusiasm and excitement, but in terms of your daily life, where might this factor in? Should we be excited? Should we care, or is it just a bunch of headlines from the span of three years that were coming up in in pop science.

JUDY: You think your latest, greatest laptop or smartphone or smart watch are examples of state-of-the art computing? She calls these examples of classical computing, based on the binary system of ones and zeroes that’s been around since the very first primitive computers.

KADE: And so they have a series of switches that can be on or off. And this is how computers store and process information.

GEORGE: But in quantum computing, there are things called quantum bits--qubits, much more versatile. They can be zeros or ones or both at the same time, or anything in between. Somebody at IBM talked about the difference this way: You’re standing in the middle of a maze and you use a classic computer to help you get out. It tries every possible combination of paths until it finds the exit. Quantum computing gives you a bird’s-eye view of the maze, testing multiple paths simultaneously, quickly figuring the way out. IBM fellow Dr. John Smith:

DR. JOHN R. SMITH: A quantum computer uses qubits. And qubits are not just in a state on one or zero, they’re actually in all states at the same time. So what this means,  is you can solve problems where the computer is, essentially,  looking at all the different possible paths for the solution in parallel, like at once. 

JUDY: Only problem here…you might be able to lug your laptop into that maze but you can’t bring along a quantum computer, because the electronic components that make it run have to be cooled to well below minus 400 degrees Fahrenheit. That’s because those qubits are kind of unstable at higher temperatures.

KADE: This information is more delicate, so we have a lot more information that we can kind of densely pack into these qubits, but that information disappears rather easily. If we look at it, it's gone. It also interacts with other things and has kind of many more issues than our classical counterparts.

JUDY: One of those issues is noise.  (white noise)

Some people like white noise to help them sleep. But in quantum computing, noise--the often random behavior of those qubits--introduces errors. And that keeps scientists awake at night.

KADE: So right now we're still exploring and optimizing different hardware platforms. We don't know which one is the the best platform option. We don't know how to optimize them. We don't really know we're exploring pretty much everything. There are devices that do work, but they have some issues with noise, and so we're still really trying to figure out how this hardware is going to work and how we'll use it.  We're also looking at error correction. And so classical computing wasn't practically useful until we could do error correction.

GEORGE: All hype aside, she does see great promise in quantum computing when it comes to chemistry…in a better understanding of the building blocks of things that might improve our lives.

KADE: To maybe make fertilizer more efficiently, to make drugs more efficiently, to design new materials, whatever it might be. And so that really is why chemistry came into the focus. Other people will have different answers for why this is true, because there's a million reasons why one might want to focus on chemistry. 

JUDY: She said that potential competition from quantum computers has made the software engineers who work in classical computing more innovative.

KADE: If we look at classical computing, a lot of people that work in classical computing algorithms were very mad that there was a lot of articles that said quantum computing can beat classical computing in any possible way. And so these people doubled down, and they are making algorithms that are way better than they previously were, because they don't want quantum computing to win in that sense. So that's a whole field that's been reinvigorated.

GEORGE: We’re storing more and more and more stuff on computers and in the cloud. Dr. Head-Marsden says quantum computing might help us supersize our information storage capabilities.

KADE: So right now, as a society, we are producing more data than we ever have, and we need to store that, or we don't really need to, but we want to. I guess we could delete most of our photos and we'd be fine, but we want to hold on to them. And so the idea these qubits that can hold more information. If we can design those properly, we can protect that, and then we could store information. So there are people working on quantum memories.

JUDY: A lot of that depends on whether the hardware can be made more stable and whether it’s possible to run it at normal temperatures.

KADE: Because of this low temperature restriction on some of these qubit platforms, there's an idea of, can we use molecules that are usually have quantum properties and are usually somewhat stable at room temperature. Can we design these to be qubits, to be sensors, to be probes, to be other quantum technology devices?

GEORGE: She stressed the need for continuing support of basic research into quantum computing, even if there’s so much uncertainty about how it will pay off.

KADE: There's a lot of skeptics that say there's a lot of problems with it. We might never realize what we're hoping to realize with these devices. As a counterpoint to that, There is a ton of fundamental research that's inspired by quantum computing. And so maybe quantum computing will be a next breakthrough. Maybe it won't be, but if it's not, we have all these other fields to look towards.

JUDY: And with that, it was question-and-answer time. George wondered about the fact that there are so few quantum computers available right now, owned by big corporations like IBM or Google or well-heeled research institutions.

GEORGE Is it like the very, very old days of classical computing, where everybody had to sign up for time on the mainframes and you had to wait your turn? Is that now? 

KADE:   Yeah, so that's effectively what it is right now. There a few is kind of broadly defined, so there's probably a couple of dozen that are accessible. You you have to get in a queue and everything that you just said. And so, yeah, it is. It's, it's kind of centered around these companies that have these devices that are accessible. 

GEORGE: How do you get prioritized in the queue? 

KADE: You have to make friends with the right people. 

GEORGE: It's the same old game…(laughter)

KADE: Pretty much. 

JUDY: I wondered if it would be possible to have quantum computers at home, like our present-day PC’s and Macs.

KADE: Not without some really massive jumps in technology, because right now they're kept in very controlled situations. They're very cold, they're they're very protected. And I, I don't know how you keep your house

JUDY: Swamp cooler wouldn’t do it? 

KADE: I don't think so. 

GEORGE: How about classical computers in our homes and our offices being able to tap into the quantum computers. Yes, is that coming soon? 

KADE: It’s here now. There’s a cloud based service you can log into and access IBM’s devices. 

JUDY In preparing some questions for this, I, you know, I consulted my regular old computer AI named Claude and asked him about how this this quantum computing, would change our lives. And one of the things they mentioned was cryptography and security, and it said this will undergo a fundamental shift. Current encryption methods that protect everything from bank transactions to private messages will become vulnerable to quantum attacks. However, this will drive the development of quantum resistance security protocols. Sounds like blackmail from the quantum computers. I mean, it's going to first hurt it, the security, and then fix it. Do you think that that'll happen that way?

KADE: For starters, I didn't realize Claude was your AI.

GEORGE Actually, he's the secret lover she has on the side. 

KADE: There you go, Claude. 

JUDY: Claude, (laughs) 

KADE: I do think that's a possibility. I think that that's, I mean, as technologies evolve, that's I mean, we'll be able to, if we can encrypt things, in terms of using quantum mechanics to do so, then likely you can break that encryption. So yes, I imagine these two things will chase each other around. But I don't know how immediate that technology is but you will see a lot of banking companies and the likes have have created quantum computing positions. And so I imagine that's something that people are looking towards

JUDY: Weather forecasting as well. That will become more precise. Claude says. (laughter)

KADE: So I think that comes into kind of a metrology type area so a quantum sensing so certain. When you prepare those qubits in superpositions, you can sometimes have more sensitivity if you want to measure something. And so I imagine that's where they're looking. But all of these things are, again, kind of a little bit further along than where we are right now.

GEORGE: You mentioned, noise is a problem in quantum computing. In the old analog world, we perceive noise as static on the radio or snow on the TV, but in quantum computing, it comes forward in the form of errors, right? Yes, so classical computing has error correction. But how difficult is it to do that in the quantum world?

KADE: It’s not easy. The most common way right now is through using more qubits as backups. So you have your one qubit, that is what you're hoping will work, and then you have a bunch of other qubits that are there that are copies of that information. If you lose it, you can maybe try one of those. Having to add a bunch of extra qubits to stabilize or to protect one qubit means it's really hard to make use of these devices, because that really, if you only have 1000 qubits, and every single one that you want to use needs six friends To make sure it's okay, you rapidly run out of space. Noise really is and errors are really your your biggest issue with with scalability and usability.

GEORGE: Is noise the biggest challenge in quantum computing right now, or are there others that surpass that?

KADE: I think that noise in general is the biggest challenge.

JUDY: I'd like to get back to the potential applications, and you mentioned several, and I'm thinking about energy transfer, which would be a game changer for things like solar, energy storage. And what's fascinating when I was reading about this is that you're using this amazing quantum computer technology to understand how plants and bacteria transport energy, which is really going back to basics. I mean, does it give you a sense of wonder at how amazing the simple biology is? 

KADE: I think any research gives you a sense of wonder, because nature does things better than we will ever get even close to doing it. But I think the problems you're referring to are, there's a lot of research that goes into looking at how is energy transported from the surface of a photosynthesizing being. So a bacterium, a plant, how does it transfer that energy from the surface of its being to its reaction center, where photosynthesis can occur so efficiently. Because if we could understand that, we could reproduce it, and then our energy transport would be much more efficient. Modeling that is really challenging and there’s a lot of work that goes into making approximations and people really do a good job that way, but that’s the application you’re referring to, I think.

JUDY: And sort of stunning, that basically you're going back to basic biology.

KADE: Yeah.

JUDY: So that the quantum computer, which is incredible, can copy it, right?

KADE: Yeah.

GEORGE What spurred your interest in science initially? Why did you decide to pursue this path? 

KADE: That's a good question. I was a math kid, and so I did my undergraduate in mathematics, and then wanted a application to kind of rigorous mathematics, and so quantum mechanics was a good option for that route, and then I kind of just fall into it from there, I think. But really it was just, I think the way my brain was wired. Math and puzzles is pretty much all I do.

JUDY: Puzzles?

KAADE: Any kind.

JUDY: Wordle?

KADE: Every day, every day.

JUDY: Now…

GEORGE: We’re all in sync here. Now

KADE: I made, I made daily quantum Wordles for my students in my undergraduate quantum class.

GEORGE: A quantum Wordle?

JUDY:  Really? 

KADE: Yep. It was awful, though, because it was I made them themed for the lecture, and then I couldn't say the word and so it was one of those things start your lecture and you're like, Oh, that was a good choice and a bad choice, because now I got to avoid the topic of today's lecture…

JUDY: Because it gives away the Wordle. 

KADE: Yeah, yeah, 

JUDY: That's marvelous. And, and do you see more young people, young women, coming in to the field? It's a new field. 

KADE: Yeah, it's a new field. I think it's starting. I think there's still, it's, it's still not at equality. It's not, it's the numbers are moving in the right direction, but I think slower than maybe we would hope that they would I am in a department right now that is more than half female, but it just if you're looking at then theory and quantum information, those numbers are still down, but I do think chemistry in general is very much improving.

GEORGE: We had a speaker here at Telluride Science sometime back saying, if you think you understand quantum mechanics, you don't understand quantum mechanics. 

KADE: Yeah. So yep. 

JUDY: Is it that tough? 

GEORGE: Is it that tough? 

KADE: I think it's just counterintuitive. Everything that your intuition says will be true is wrong, and there's a lot of complicated pieces to it. And so I have my PhD was in something called reduced density matrices. And I still get…

JUDY: Say that, again, 

KADE: Reduced density matrices.

JUDY: Oh, sure, 

KADE: Just an object. I know it's not great. The point is that I still get in arguments with my colleagues daily about fundamental things about this. So we it's, it's challenging, and again, it's counterintuitive, and it's not tied to reality in some ways. And so I think it is, it's and every time you learn more about it, you can get more confused. 

JUDY: The most dramatic improvements through quantum computing may be in health care and drug development. And do you see that as potentially a huge area of development for quantum?

KADE:  I think there's a lot of hope that that is true, and a lot of investments in the past couple of years that are pushing towards that. And so Cleveland Clinic has a quantum computer in the hopes of using that for medical applications. Novo Nordisk, the company that made Ozempic in Denmark, they have invested a lot of money to build a large quantum center in Copenhagen that will it was basically pitched as a quantum computing for a life science type application. They consider chemistry to be life science, which is flattering, but a lot of it is drug discovery, health type applications.

JUDY: Here’s a fun fact about the Cleveland Clinic’s quantum computer.  They were so proud of it, they stuck it in a lobby for everyone to see. It resembles a chandelier under glass.

GEORGE: Well, I think we're going to open it for questions from the audience.

MAN IN AUDIENCE: Can you give us another sentence or two on what a qubit is that is, a lot of us think we sort of understand a switch on a chip that’s either on or off, but what is a qubit?

KADE: Sure, so that's a really hard question hardware wise, because there are so many different platforms. So depending, in the most fundamental sense, it is something that has binary options and that you can also have something in between. And so, the superconducting qubits that I have those chandelier cartoons of, those are what is called Josephson junctions which is an etching into a chip that creates this two-level system. 

GEORGE:  There’s one back there. 

WOMAN IN AUDIENCE: So a lot of these superconductors are at very low temperatures. And I've kind of read that there are some more, like high temperature superconductors with like cuperates and things like that. So I just wanted to understand more about the temperature dependence and why we aren't yet using these high temperature devices?

KADE: Yes, that’s a really good question. It’ll be very much specific for one of these devices. If you read something specific that contradicts me, they are the boss. But one of the major things is this idea of noise. And so as you increase the temperature, it's much harder to hang on to the state that you want. And so that superposition that I’ve showed, that in-between off and on, if I heat things up, there are more vibrations in the things you’re looking at, there’s temperature, there’s a lot happening in that space that’ll disturb your state. And so the really cold systems are because there's just less going on when it's really cold and the noise is at its minimum, and so the higher temperature options will hopefully be where we're headed, because that's how you can kind of not have to have a whole basement full of cooling to keep one machine alive. But it's just hard to figure out, how do you control and actually manage to stabilize those states when you have temperature fluctuation? Vibrations, and you have vibrations in kind of whatever lattice structure you're ever else. And so it really is just a function of noise, I think. Thank you.

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JUDY: Thank YOU, Dr. Kade Head-Marsden for joining us. And thanks to Telluride Science for making her appearance possible.  Her talk was recorded before a live audience at the Telluride Conference Center in Mountain Village Colorado. Dean Rolley was our audio engineer.

GEORGE: Also, a  major thank you to our sponsors, Alpine Bank and the Telluride Mountain Village Owners’ Association.

JUDY: Mark Kozak is Executive Director and CEO of Telluride Science and Cindy Fusting is Managing Director and CFO. Sara Friedberg is Lodging and Operations Manager and Annie Carlson is Director of Donor Relations.

GEORGE: If YOU want to donate to the cause, go to Telluride Science-dot-ORG. That’s also where you can find our podcasts. And on your podcast apps like Spotify or Apple, look for “Science Straight up.” I’m George Lewis.

JUDY: And I’m Judy Muller, inviting you to join us next time on “Science Straight Up.”

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