"Quantum" is everywhere these days — in the news, on TV, in the titles of blockbuster action films — but what even is it? Why is it important to understand it? Basically... who cares about quantum?
To find out, we got philosophical with National Lab quantum scientists Anna Grassellino and David Awschalom about their brain-bending research, the massive impacts it could have on our lives, and the joy and frustration of chasing breakthroughs that can take decades to arrive.
Also: Season 4 of Direct Current is coming soon! Subscribe today wherever you get your podcasts to get a fresh delivery of energy audio goodness in your feed when it drops in spring 2023. Don't miss it!
What Is Quantum?
Explanations of what quantum science is — or does, or could do — abound. But, as we cover in this episode, those explanations can be a mixed bag when it comes to such a thorny scientific topic. Argonne National Laboratory has some great resources for the quantum-curious, including video explainers, graphics and more.
Plus, here's Argonne's own David Awschalom, who we interviewed in the episode, talking about our Office of Science's groundbreaking work to drive quantum science forward.
A National Approach to Quantum
This episode features quantum insights from Anna Grassellino, Director of the Superconducting Quantum Materials and Systems Center, which is based at Fermilab in Batavia, Illinois. The center and its 20 partner institutions is one of five national centers involved in advancing quantum research as a part of the U.S. National Quantum Initiative. Grassellino and her team are building a beyond-state-of-the-art quantum computer based on superconducting technologies and will also develop new quantum sensors, which could lead to the discovery of the nature of dark matter and other elusive subatomic particles.
Quantum Computing, Explained
Quantum computers harness the laws of quantum mechanics to perform certain calculation exponentially faster than today’s supercomputers. This means quantum computing may revolutionize our ability to solve problems that are hard to address with even the largest supercomputers. Scientists have demonstrated these quantum speedups in several applications, including database searches. The race is now on to find others.
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MATT DOZIER: Hey there, Direct Current listeners. I know it’s been a while since you’ve heard from us, but we are coming back. Yes, *Season 4* of this podcast is coming soon, which means a bunch of new episodes about clean energy, the electric grid, big scientific breakthroughs, energy justice — all just around the corner. So stay tuned. But first! To get you excited for the new season, we’ve got an episode for you about one of the biggest buzzwords in science today — quantum. (ECHOES) You may have heard it in the news lately, in headlines about quantum computing, “quantum entanglement,” or in popular media — books, TV shows, certain really huge blockbuster superhero action films… Well, whatever you want to call it, “Quantumania,” “Quantumonium” — we are reaching new levels of Quantum Madness. And there’s good reason for that. There have been a bunch of exciting breakthroughs in the field in recent years, and we’ve learned a lot about how things work in the realm of quantum. There’s also just something about quantum that seems to grab people’s imaginations. The whole concept is just kind of… well, to borrow a quantum science term, spooky. So now that quantum is becoming more and more a part of our cultural vocabulary, we have to ask the question — What is it? Why is it important for all of us to understand it? Basically, who cares about quantum? To answer those questions and more, we went to the experts.
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DAVID AWSCHALOM: At the end of the day, quantum physics really is a set of rules that describe how nature operates at its smallest scales. And by smallest scales, I mean, atoms, electrons and photons — that is, particles of light — and how they interact with each other.
MATT DOZIER: That’s David Awschalom. He’s a professor of Molecular Engineering and Physics at the University of Chicago and senior scientist at Argonne National Laboratory.
DAVID AWSCHALOM: Our research focuses on, well, creating and controlling quantum states and matter. And we do it to explore both scientific questions and really to investigate potential applications. And we do this with two different approaches. One is using semiconductors. So materials that are the basis for much of our existing electronics today. And another, I'd say more radical, approach is literally building quantum bits from the bottom up using molecules. And in both of these, the aim is to create quantum states of matter, control their properties and make them as robust as possible.
MATT DOZIER: Is your head spinning yet? Don’t worry — you’re not alone. Even the most basic concepts in quantum mechanics — things like superposition and quantum entanglement — can be hard to wrap your head around. And for scientists like David, that can pose a real challenge when trying to explain their work to non-scientists.
DAVID AWSCHALOM: Let’s say, I think it's important to focus on the concepts themselves, you know, not the nitty gritty, not the mathematics, and appreciate that most of us don't have a natural intuition for quantum behavior. So, take superposition. And you might say, like, how does one explain this? You know, we think about a coin being heads or tails. But if you spin a coin on a coffee table, I think it helps visualize a quantum state of being as the coin spinning. Is it heads, or tails? It's a superposition of both, and we don't really know the answer, what the coin is, until we probe it, right? It becomes either heads or tails based on when, and how we touch it. We tend to explain this field as moving us from a technology of binary bits to quantum bits. It's, I guess, it's not unlike moving from a world of black and white to color, delivering a much richer canvas of options here.
MATT DOZIER: Coming up with the right language to describe a concept in physics is tough. Spinning coins, Wizard of Oz-like leaps from black and white to color — we often search for analogies to everyday life that can help bridge the gap in our understanding of more complex concepts. And David said the creative metaphors he and his colleagues use to translate quantum behavior can be helpful, but initially, don’t always land right.
DAVID AWSCHALOM: So I think, admittedly, a lot of it's been trial and error, maybe starting with a lot of error. When you realize initially, a lot of these things aren't being understood, the problem tends to be me, right? Not the other person. So we sort of back up and think more deeply about what it is you're trying to explain. Honestly, you have to really understand things at a deep level to explain it simply. But it's really important for the public to understand this.
MATT DOZIER: There are a few different reasons why that is, but one of the big ones is that people want to know how this research is going to impact their lives. If you tell someone you’re a quantum scientist, the conversation pretty much inevitably turns to some form of — sounds interesting, but how does it affect me?
ANNA GRASSELLINO: Well, they typically say, Oh, that's so incredible. That's so cool. But what can a quantum computer do? Right? That's always the first question that we are asked, and that's the hardest question to answer.
MATT DOZIER: Anna Grassellino is a senior scientist at Fermi National Accelerator Laboratory and the director of one of five Quantum Information Science Research Centers operated by the Department of Energy.
GRASSELLINO: Quantum computers, as of today, I think it would be lying to promise, “Oh, they will solve this and this other, you know, very important problem.” So, we are at a stage where we know that there are applications and fields where a quantum computer can surpass the current capabilities that we have with classical computing, but we are not there yet. We are really at the technology development stage.
MATT DOZIER: Quantum computers are, at least in theory, supercomputers that will take advantage of quantum mechanics to vastly increase computing power, so we can tackle scientific problems that would have taken current-generation supercomputers decades to solve. The quantum center Anna leads is this huge collaborative effort that focuses on developing the world's most powerful quantum computers and sensors using superconducting quantum materials. So she’s very familiar with both the limits of these technologies — and their enormous potential. Ready for another quantum metaphor? Buckle up!
ANNA GRASSELLINO: One of the things I say is, don't compare a quantum computer to a classical computer as you would compare an old car to a new car. The better comparison is, let's say, an airplane to a car, right? So a quantum computer does not replace the car, right.
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ANNA GRASSELLINO: And in fact, you're not going to take an airplane to go from Batavia to Chicago. But you must take an airplane, right, to fly over the ocean. So that's typically what we try to use in simple terms to say, it's a tool that will allow us to do things that today we cannot do, but will not replace necessarily the tools that we currently use for more simple tasks.
MATT DOZIER: Then there are other potential applications, like quantum sensing, which could aid in the search for dark matter, or detect earthquakes before they happen, or reveal the existence of new particles. So there’s value in helping the public to understand the impact that quantum science could one day have on their lives — and also to have realistic expectations for what it can and can’t do. But there’s another big reason why scientists like Anna and David care whether anyone outside their profession learns about quantum. To put it bluntly, we need more quantum scientists!
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DAVID AWSCHALOM: So right now, the competition for students is unlike anything I've seen in my career in science. You know, the combined needs of industry, National Laboratories, such as Department of Energy’s, universities around the country — these needs and demands are greatly exceeding the number of people in the market. And it's a global challenge, not just one we're experiencing here in the United States, quantum programs are emerging all over the globe. It's currently estimated over $30 billion of investment is happening globally in this field. So of course, it's a wonderful time to be a student, with a remarkable set of career choices, and for students listening is likely to stay that way for quite some time.
MATT DOZIER: And those challenges we talked about earlier? About how difficult quantum physics is for our brains to grasp? That can be a real obstacle to attracting future scientists.
GRASSELLINO: It may sound very hostile to people. And people may be kind of afraid of moving into this field. And so, we do need to explain it at a level that it's understandable, but also that it's exciting. So I think that's really the key. And that's partially, I think, what we're all trying to do, the various people from industry, academia, national labs are all trying to play our part. And this does not start with a PhD, right? We have to start much earlier. And so a lot of the efforts go in K-12. So for example, one of the ideas we have here is, we are starting a new lab, which will be a really large quantum lab — one of the largest in Illinois — and one of the things that we want to do is, for example, our arts and science contacts with the various schools in the Chicago area, to tell us, you know, what do you think these quantum computers will do? And then these kids will come and decorate the walls of our labs. We are thinking in a different way, how can we involve people to push them, already at a young age, to think about this concept and think about the opportunities. Like, how can you change the world?
MATT DOZIER: Of course, one of the main ways young people get exposed to new ideas and concepts like this is through popular media. In fact, David said it’s a big part of what eventually steered his curiosity into a scientific career.
DAVID AWSCHALOM: I had been a voracious reader of science fiction, and always interested in exploring the unknown. Growing up, books like Isaac Asimov’s “Fantastic Voyage” really opened my mind to new perspectives. And actually, the idea of thinking small to think big, was a pretty exciting concept.
MATT DOZIER: David actually got an opportunity to address that connection between pop culture and hard science directly at a screening of a certain big-budget action movie featuring Paul Rudd and “quantum” in the title. We talked ahead of the screening, which was organized by Argonne National Laboratory and followed by a panel discussion involving David and other quantum researchers about the fiction vs. reality of quantum.
DAVID AWSCHALOM: Well, I haven't seen the movie. So I'm looking forward to it myself. And understanding how Hollywood is taking this stuff of reality and turning it into fiction, and vice versa. I think this is an incredible opportunity to engage the public in an entertaining way to appreciate that this is a time when we're moving from science to technology, maybe not shrinking things, but being able to think about information and how you move things around in a very different fashion. So I think it's a way to capture the excitement of the field. And the panel afterwards, Matt, that you mentioned, I think, was a great way to put a put people on the face of this, understand that people in this field, face challenges are inspired in ways that everyone in the audience is too, and maybe share some background information and get to learn a little bit more about each other.
MATT DOZIER: It’s honestly hard to overstate the passion and enthusiasm the researchers I spoke to have for their work. There’s just a sense of real possibility and excitement, of being on the verge of something really huge — even if we don’t know quite what it is yet. I asked Anna what she’s most excited about for the future of quantum science.
ANNA GRASSELLINO: Well, there is too much, I think, in my opinion, to choose from. What is really important, in my opinion, is in science to have ambitious goals, and to push technologists towards unprecedented frontiers, unexplored territories, because ultimately, we're aiming at building the best quantum computer in the world. And we are really stepping into unexplored physics territory when we do that. Maybe in the end, the return is not the quantum computer, maybe it will be a fundamental physics discovery. So I think that is the part that excites me the most, right, this is what I've been fortunate enough to witness in my background, as a scientist. We’ve tried to get out of our comfort zone and try new things, exploring new things, and we found something completely that we didn’t expect. So I think that's, in general, how physics has always worked, right? You chase something. And then in the end, if it's ambitious enough, you may find something else.
MATT DOZIER: That uncertainty is part of what makes this field so compelling.
DAVID AWSCHALOM: One of the most exciting things I'd say right now, for a lot of us is, while we've talked about some pretty exciting developments on the horizon, in these different areas, I think it's safe to say it's likely that the biggest impacts have yet to be discovered. You know, we talked about reading science fiction, when you read the history of the development of things like the transistor, it was hard at that time for anyone to imagine integrated circuits, right, that you'd be making billions of these on a chip. Mobile phones, GPS, supermarket scanners, right? Or, God forbid, social media.
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DAVID AWSCHALOM: Many of us believe we’re at this moment in time in the quantum world — essentially, the discoveries of effectively a quantum bit or quantum transistor. So to me, it's really exciting to think about where this will go. And the fact is, we need to be ready, because we don't actually know. But it will happen.
MATT DOZIER: It's almost a little overwhelming, but that’s what science is about — working toward something that doesn’t have a definitive, known ending. Trying, failing, and then trying again. And sometimes it’s about devoting your life’s work to something huge — even if you might never see it pay off.
ANNA GRASSELLINO: The scale of the challenge is so grand that it can be discouraging, right? Like if I have my colleagues here, I energy theorists, and you ask them, Okay, how many qubits are you going to need to do this very important calculation for our field and they say, you know, millions, and they have to be with this performance, and that it's going to take 15, 20 years to get there. If ever, right? And so those are discouraging moments. But if we look back at the history of technological developments, we have to accept that important things are not solved one day to another, right? It takes time, and we have to be patient, and we have to know that it's worth it and we have to know that maybe it's another generation that will get there — but we have to do our part.
MATT DOZIER: So, who cares about quantum? David and Anna care. So do their hundreds of colleagues across the Department of Energy, National Labs and partner institutions. And after these conversations, frankly, so do I. And you should too.
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MATT DOZIER: That’s all for this episode of Direct Current. Thank you to my guests, David Awschalom and Anna Grassellino. You can find more about their research, and our National Labs’ amazing work on quantum, in our show notes, and at energy.gov/podcast. Thanks as well to our Office of Science, and to Ashleigh Papp, who contributed to this episode. Subscribe to Direct Current on Apple Podcasts, or wherever you get your podcasts, to get Season 4 in your feed when it drops this spring. Direct Current is produced by me, Matt Dozier. Sarah Harman creates original artwork for all of our episodes. This is a production of the U.S. Department of Energy and published from our nation’s capital in Washington, D.C. Thanks for listening!
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