Daniel and Kelly’s Extraordinary Universe - What is a Quantum Dot?

Episode Date: February 25, 2021

Daniel and Jorge break down the quantum world into tiny dots that have amazing properties. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

This is an I-Heart podcast. Don't let biased algorithms or degree screens or exclusive professional networks or stereotypes. Don't let anything keep you from discovering the half of the workforce who are stars. Workers skilled through alternative routes rather than a bachelor's degree. It's time to tear the paper ceiling and see the stars beyond it. Find out how you can make stars part of your talent strategy. at tear the paper sealing.org. Brought to you by opportunity at work in the ad council.

I'm Simone Boyce, host of the Brightside podcast, and on this week's episode, I'm talking to Olympian, World Cup champion, and podcast host, Ashlyn Harris. My worth is not wrapped up in how many things I've won, because what I came to realize is I valued winning so much that once it was over, I got the blues, and I was like, this is it.

For me, it's the pursuit of people. greatness. It's the journey. It's the people. It's the failures. It's the heartache. Listen to The Bright Side on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. Have you ever wished for a change but weren't sure how to make it? Maybe you felt stuck in a job, a place, or even a relationship. I'm Emily Tish Sussman, and on she pivots, I dive into the inspiring pivots of women who have taken big leaps in their lives and careers. I'm Gretchen Whitmer, Jody Sweetie. Monica Patton.

Elaine Welteroth. Learn how to get comfortable pivoting because your life is going to be full of them. Listen to these women and more on She Pivotts, now on the IHeartRadio app, Apple Podcasts, or wherever you get your podcasts. Hey, Daniel. I found another physics-related scam recently.

Uh-oh. Did someone try to sell you quantum Girl Scout cookies again? Girl Scout cookies do seem to quantum tunnel into my stomach pretty easily. I don't even have to eat them. So then what's the scam? I saw an ad for a quantum television. Can you believe that nonsense? Actually.

Wait, what do you mean? This is a real thing? What does the quantum TV do? Is it always fuzzy because of the uncertainty principle? Yeah, you know, the word quantum gets a view? a lot, but this one time, it's for real. It's not a scam? No quantum televisions are a real thing, and they are extra crispy.

Mmm, just like a Girl Scout cookie? I am Horham, a cartoonist, and the creator of P. H.D. Comics. Hi, I'm Daniel. I'm a particle physicist and I'm at least 25% made out of Girl Scout cookies. Oh, wow. You're a big fan? It's for a good cause. You know, that's why I eat them. It's for a good cause. You know you can buy them and not eat them. What? That would be offensive. You're going to throw them in the trash? You don't have to tell the Girl Scouts. They would know. But welcome to our podcast, Daniel and Jorge, Explain the Universe, a production of I-Hard Radio. In which we take our cooking. fueled brains and try to understand everything about the universe, not just the tiny quantum particles

and the crazy stuff happening at the center of stars, but everything in between. We take that immense mental journey all the way out into the universe and back into the quantum particles and explain all of it to you. Yeah. Do you have a favorite Girl Scout cookies, Daniel? Oh, we're getting real here, huh? I'm not going to endorse one particular Girl Scout cookies. I got to go, I think, with the classic thin mint, you know, it's just, it's so easy for them to tunnel into your stomach. My spouse would be appalled at the mixing of mint and chocolate. Do this taste like toothpaste to her? Yeah, with chocolate.

There's probably a reason there's no chocolate toothpaste flavor. But there are a lot of interesting and amazing things in this universe that we like to talk about in this podcast, things that are out there in the vast reaches of space and also things that are right here at home and things that are maybe at the tip of your fingertip without even knowing. Yes, things that are harder to understand even than the combination of herbs and chocolate, things that are weird, things that are quantum, things that make no sense, but are actually real. Yeah, because physics reveals that the universe is a pretty weird place. It doesn't always work the same way that we grew up thinking that it worked. There's all kinds of strange things

going on, especially at the microscopic and at the quantum level. Yeah, that's basically the job of physics is to figure out how does the world actually work. Not the way we thought it should work or the way we might have imagined it worked from our experience with rivers and rocks and stuff, but the way fundamentally things actually happen. And sometimes that's just for our edification, just to know how the universe actually works, but sometimes it's actually useful and we can use it to build cool new stuff. Wait, what? Physics can be useful?

Who told you that? Some physicist. Your parents. Some physicist after he sold me some cookies. Oh, right, right. Is there an age limit or professional limit to being a Girl Scout? You've never had a physics scout cookie? Does it taste like particles?

I hear the Higgs boson is pretty tasty. Everything tastes like particles, man. Everything is particles. Particles are also the only things doing any tasting. Yeah, you're saying that physics can be useful. Physics can be useful, yes. In fact, you know, the World Wide Web was invented at a particle physics laboratory and all sorts of things come out of just like gaining knowledge about how the universe works.

Right. And we all know how useful the World Wide Web is. That's right. It's contributed to a huge decrease in productivity worldwide. It's like an anti-useful particle there. Depends on your goals, man. Of reducing work. But yeah, well, I do admit it's useful to know physics for sure.

And sometimes we can use that knowledge to build amazing and cool things that we couldn't do before. And that includes maybe quantum mechanics, which is like the weirdest and most awesomeest thing in the universe. It is. And our understanding of quantum mechanics underlies most modern electronics. It's the reason that your phone works. It's the reason your computer boots up. It's also the reason your computer crashes, I guess. No, that's the fault of the girl's got cookie crumbles that fell on my keyword.

It's like a physical virus infecting your computer. Yeah, quantum mechanics helps us not just kind of understand what's happening with our electronics and everything around us, but you can actually use some of these weird quantum effects to do interesting things like microscopes, right? Like electron microscopes, they work on quantum mechanical principles. Yeah, basically everything that works at the very small scale that uses one or two or a small set of particles has to follow quantum rules. So anything that's been super miniaturized or uses particles to look at super tiny stuff has to follow quantum rules. And sometimes those quantum rules are different in a really useful way. Yeah, and usually this kind of technology is limited to physics labs and engineering labs and research centers. but soon quantum mechanics technology might be coming to your home.

That's right. Get ready to buy quantum cookies. I know. I mean, quantum TVs. You know, there is actually something quantized by cookies. You notice how you can't eat one and a half cookies or three and a quarter's cookies. It's always like integer numbers of cookies. Oh, my God.

You just discovered the Whiteson quantum cookie principle. I did a lot of experiments. It's more of a social science principle, though. Yeah, it's a bit of a. soft science. The more right cookies I get, the softer my science is. And your stomach and your body. Exactly. Well, there is now a proposed quantum television technology and it's based on kind of not a new technology, but a technology that's been around for a while in quantum mechanics. Yeah, this is really fascinating idea that lets us build something like artificial atoms and

manipulate electron energy levels to get all sorts of fascinating properties that we could use for really a wide range of possible technologies. So to the end of the program, we'll be talking about what are quantum dots. That does sound like a Girl Scout cookie. A very, very small cookie. The quantum dot, you know, what is it? Thin mint and snigger doodles and quantum dots.

But how many quantum dots would be in one box of cookies, right? Like 10 to the 26? That's a pretty good deal. Mom, I only had 10 of the 12 quantum dot cookies for dessert. That's your allotment for the rest of your life. So when you heard the phrase quantum dot, did you think it was another one of these ridiculous schemes? Yeah, I'd heard of them before. I just never knew what they are.

I mean, I imagine they're just really small dots at the quantum level. But, you know, is it like a dot of ink? A dot of what? It's a dot of quantum, right? Pure quantumness. All right, well, as usual, Daniel went out there. into the wilds of the internet to ask people if they knew what quantum dots are. So thank you to everyone who broke through their inhibitions and answered these random questions without any research.

If you'd like to participate in the future, please write to me at questions at danielanhorpe.com. Yeah, so think about it for a second. If someone asked you what a quantum dot is, what would you answer? Here's what people had to say. I think a quantum dot refers to a single particle such as an 11. that is isolated by means of electromagnetic fields. The particle is confined to a small region in space, so it has a very high kinetic energy.

Okay, I think quantum dots are really small collections of atoms. I believe often it's four gold atoms to lump together. together. Maybe if the idea that like the universe is pixelated, maybe quantum dots are the grid points that underlie everything. If I had to guess, I would say quantum dots are maybe something like string theory, where if we break things down as small as we can get, we're stuck with these quantum dots and they can be the building blocks for a lot of quantum things. I think Cori said it once. The word quantum just goes in front of anything these days, it seems like.

I don't know for sure, but I think it might refer to the mathematical concept of a particle that doesn't have a volume. So it only has coordinates, but no volume in space or zero volume. Quantum is something small, and a dot, it's something small also. so quantum dot probably you'll find it in a at the end of a quantum sentence. How about that? So I've never actually heard the phrase quantum dots before. My guess is that it has to do with the idea that space itself is quantized and that if you were able to zoom in far enough, there would be a smallest possible.

point? I've never ever heard of a quantum dot, I'm afraid. I'm guessing they have something to do with the idea that space is quantized, so like pixels on a display. All right, not a lot of people know what a quantum dot is apparently. No, but there are some really nice

speculations here, like the math concept of a particle with no volume. That's definitely something we've talked about in the podcast. I guess everything is a quantum dot technically, right? Like all particles are just point particles. What's the difference between a dot and a point, Daniel?

Oh, man. Let's get philosophical. One of them has mint in it, I guess, and the other one doesn't. I have no idea. I have no idea. When it's round, maybe. The other one is pointy, maybe. Yeah, I don't know.

A point, technically speaking, is a single value in space, whereas I guess a dot could have some width to it. You have a good point with dot. All right, let's jump into it. Daniel, what is a quantum dot? Set all this for us. Quantum dot is really fascinating. It's basically just a piece of semiconductor, but a very, very, very small piece. So you get interesting quantum effects.

And because semiconductors are sort of very flexible electrically and can be manipulated by doping and adding different kinds of materials, you can essentially construct any kind of energy levels you want for your electron, which is really what determines the sort of like bulk properties of a material. So it's just a really, really tiny piece of anything, right? It doesn't have you a semiconductor. Here it can be any material that you can call it a quantum dot. Yeah, it could be any material, but we typically use semiconductors because of their interesting electrical properties. And so take some piece of material and make a really, really small version of it and then quantum effects take over. Things like the electron, for example, gets trapped in your quantum dot.

And then the width of it is now important to how that electron behaves. It changes like the energy levels the electron can have, which changes like how it absorbs light or emits light or conducts electricity. How big are we talking about or how small are we talking about it? talking about these quantum dots being, like how many nanometers? We're talking about like one to 10 nanometers in size. These are really tiny. Like you could line up a million of these things across your finger. They're super duper small.

And they have to be small in order to get to the quantum effects, right? They have to be basically on the quantum scale, the Ant-Man scale. So one to 10 nanometers. And how does that compare to like the, you know, the quote-unquote width of an atom? it's about 10 or 15 times wider than like the hydrogen atom that's defined by like you know the cloud of electrons around the nucleus so you're definitely getting down to that scale wow and i think that's sort of the key idea is that you know when you get electrons down to this really small scale like the size of a hydrogen atom or what happens in atoms they start to exhibit these quantum properties like having very specific energy levels that only happens when you can strain an electron all right so you know it's like maybe 10 atoms wide, these dots, and are they actually like dots? Are they like cubes? Are they like little balls? Do we have pictures of them? We do have pictures of them. Usually they're little crystals. And it depends a little bit on how they are built and how they're fabricated.

And we'll get into it in a minute about how you make these things. You can make them in almost any shape. You can make cubes. You can make pyramids. You can make, you know, diamond shapes, whatever you like. And the shape of the nanocrystals changes how the electron is sort of capture it in it. and can change its behavior. So depending on what you want for its electrical properties, you might design a different shape. All right. So it's almost like you're kind of making an atom almost.

Yeah. The key idea here is that when you look at the periodic table, you see lots of different elements. And those elements all have really different properties, right? Some of them conduct a lot of electricity. Some of them are really interactive and some of them are not. All of those properties come from the behavior of the electrons and their energy levels. Like are those electron orbitals filled and how big are they, et cetera, et cetera.

But we're sort of limited to the atoms that we have in nature. You know, if you want an atom that does a specific kind of thing that emits light at a certain frequency or absorbs light of a certain frequency, you sort of have to pick from the menu that we have until now, because quantum dots allow you to basically engineer electron energy levels to say, I'd like electron energy levels that look like this, so it can have whatever, whatever property. That's why they're sometimes called artificial atoms. They don't have a nucleus and electrons around them, but they have that sort of property

of an atom that they're controlled by their electron energy levels. Interesting. They're like designer atoms. Yes, exactly. Designer atoms. Like made to order. Yeah. And so if we want a material that does something that no natural material does,

then we could maybe build it out of quantum dots or design quantum dots that have that specific ability. What kinds of abilities are we talking about? Like reflecting light or like how they conduct or how easily they give off an electron or how they taste? I would not recommend eating any of these quantum dots. Almost all of them are totally toxic. But yeah, they have interesting optical properties.

Like they can absorb light at whatever frequency you want, you know, and they can give off light at whatever frequencies you want, which is very helpful, for example, in making a very crisp display for your television and other kinds of things like absorbing power for solar cells. And there's another aspect to it, which is maybe less practical, but more fascinating, which is that you can sort of design quantum behaviors. Previously, when people wanted to do quantum experiments, it was hard because you had to use, like, actual atoms that we find in nature. And those atoms can be difficult to deal with. You have to, like, have a vacuum system and lasers to capture it. Remember, we talked about Bose-Einstein condensate. It's a difficult thing to do because it has to be done with atoms and all these complex systems. Yeah, I lose my atoms all the time.

They're slippery. They are slippery. And it's a pain and it's expensive. but if you could do it with quantum dots, they're much easier to manufacture. You might even be able to print them on chips, for example. So you could do all sorts of fascinating quantum experiments without all the expensive machinery.

Wow. Could you print like a quantum computer out of quantum dots? Yes, exactly. That's one direction people are going, trying to build qubits out of quantum dots. But doesn't the quantumness of something always decreased, the more atoms you get? Like if you have 10 atoms,

that's usually sort of like, less quantumy than one atom. Right. You can worry about like decoherence effects as it interacts with its environment. It loses some of those quantum effects because the way functions decoher. And that's something that's really difficult to do with atoms because it's hard to isolate them from the system, right? The key is isolation. You could have a really large system that doesn't decoher as long as it remains isolated from the environment. That's hard to do with atoms because you know they bounce around and they jiggle and stuff. But quantum dots are sort of easier to localize and therefore easier to isolate is the idea. Oh man. Are we going to go back to dot matrix printers? But this time

there'll be quantum dot matrix printers. Yeah, exactly. Is that our future again? And then we'll go back to quantum modems too. But it'll be the quantum version of those sounds. So it'll be much spookier. Sound cooler just by definition. And something that's really fascinating about these things is that they're often referred to as zero-dimensional objects. Of course, because that's not confusing. I know. And that was really confusing for me when I first was reading about that because, you know, I'm three-dimensional.

There's forward backwards, side-to-side, and up and down. I'm defined by three different dimensions. And you can imagine, you know, a sheet of paper is almost two-dimensional. And like a thin piece of string is like almost one-dimensional. What's a zero-dimensional object? And it's really something where it can't go anywhere. So it's really like a point in space. Yes, there are electrons in there and yes, technically they can move a little bit sideways,

but really they're constrained and the only way they can move is sort of up and down in energy. Oh, interesting. Almost like a perfect box for electrons. Yeah, it's a perfect little box for electrons. And, you know, quantum mechanically, the way the electron behaves is completely defined by the shape of the box. Like an electron just floating through space is not actually quantized. Like you could have any energy level. Free electrons are not quantized at all.

The quantization only happens when you constrain it. When you say, you've got to live in this little box or whizz around this nucleus of the atom. That's where the quantization comes from. And so here by constructing your own box, you define your own energy levels for the electron, which I think is pretty cool. So we're like quantum designers. Wow. And this is an idea from the 80s that was made a long time ago, but only now maybe we're getting into how to actually use these thoughts. Yeah, exactly.

The idea has been around for a few decades. and the proof of principle was done in the 80s. But with lots of things, it's only really useful if you can make a lot of them and if you can make them at less than like a billion dollars per dot. Right. All right. Well, let's get into how you actually make a quantum dot

and what can you do with them? But first, let's take a quick break. A foot washed up a shoe with some bones in it. They had no idea who it was. Most everything was burned up pretty good from the fire that not a whole lot was salvageable. These are the coldest of cold cases, but everything is about to change.

Every case that is a cold case that has DNA. Right now in a backlog will be identified in our lifetime. A small lab in Texas is cracking the code on DNA. Using new scientific tools, they're finding clues in evidence so tiny you might just miss it. He never thought he was going to get caught. And I just looked at my computer screen. And I was just like, ah, gotcha.

On America's Crime Lab, we'll learn about victims and survivors. And you'll meet the team behind the scenes at Othrum, the Houston Lab that takes on the most hopeless cases to finally solve the unsolvable. Listen to America's Crime Lab on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. I'm Dr. Scott Barry Kaufman, host of the Psychology Podcast. Here's a clip from an upcoming conversation about exploring. boring human potential. I was going to schools to try to teach kids these skills and I get eye rolling from teachers

or I get students who would be like, it's easier to punch someone in the face. When you think about emotion regulation, like you're not going to choose an adapted strategy which is more effortful to use unless you think there's a good outcome as a result of it if it's going to be beneficial to you. Because it's easy to say like go you go blank yourself, right? It's easy. It's easy to just drink the extra beer. It's easy to ignore, just suppress, seeing a colleague who's bothering you and just, like, walk the other way.

Avoidance is easier. Ignoring is easier. Denials is easier. Drinking is easier. Yelling, screaming is easy. Complex problem solving. Meditating. You know, takes effort. Listen to the psychology podcast on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. When your car is making a strange noise, no matter what it is, You can't just pretend it's not happening. That's an interesting sound. It's like your mental health. If you're struggling and feeling overwhelmed,

it's important to do something about it. It can be as simple as talking to someone, or just taking a deep, calming breath to ground yourself. Because once you start to address the problem, you can go so much further. The Huntsman Mental Health Institute and the Ad Council have resources available for you at loveyourmindtay.org. All right, we're talking about quantum dots, which are not Girl Scout cookies, but possibly TVs in the future.

Yes, TVs maybe even in your present. They might end up on our phones. Yeah, you could have a quantum dots screen. They could create screens that are like really flexible. You could like roll up and stuff in your pocket. Oh, just don't eat them, huh? Do not eat quantum screens. All right, quantum dot is a little tiny piece of sense.

semiconductor, maybe 1 to 10 nanometers wide, which is about like 10 atoms in the width. And they kind of act like little designer atoms. They can trap electrons and you can make them sit at whatever energy levels you want. Yeah, you can make the particles dance whatever dance you tell them to. All right. So I guess the question is, how do you make them? How do you make a quantum dot? Do you just like spray some quantumness and they form in the air?

What's the form in it? Yeah, it's one teaspoon of quantumness, two teaspoons of dot, and then just make. mix. There you go. It's hard, right? And this is one of the challenges. And so there are a lot of different approaches to making these quantum dots. And we'll see which one sort of takes off for various applications. There's basically three totally different approaches. One is chemical. So basically just try to mix these things like we were just joking about, but for real. And the idea is that these things are crystals, which means that in some sense, they should self-assemble. You know, the way like crystals will form themselves. If you put soft,

salt into solution and you shake it, the salt should come out of the solution, you know, make these crystals. And so you do the same thing with the kind of quantum dots you want to make. Whatever it is you're trying to build. Maybe it's mostly silicon. Maybe it has other stuff in it. You put all those ingredients into some solution. You heat it up so it all like breaks up into a big soup. And then you hope that nanocrystals get nucleated and then sort of build on themselves. But then they would be floating around or they would kind of form on your source? surface. No, then they would be floating around, exactly. And then you'd need to do something to like pull them out and, you know, make them useful somehow. But often you want them in solution,

like maybe you want them suspended in water so they can glow a certain temperature where you can inject them into your experiment or whatever. Sounds kind of tricky. It's pretty tricky. And also it's tricky to filter them, right? You want only quantum dots that have formed well. And so this process isn't always going to form you high quality quantum dots every single time. And so it's tricky to get exactly the right ones out. And so people have tried all sorts of variations on this approach, like using molecular seeding, you know, starting with something that has sort of like the right shape to nucleate those crystals and encourage things to form just the right way. It's really complex sort of like as a chemistry problem, you know, how do you get all these molecules bouncing around in solution to come together and like build themselves out of these mini Legos? Right. Yeah. Sounds tricky.

What are other ways that you can make them? Another way is basically following the principles of semiconductor technologies which have come really, really far in printing tiny circuits. The way your computer is built is not by super tiny little fingers soldering together little components individually, right? It's printed onto a sheet of silicon in a super duper tiny way. So they have developed this technology because it underpins the entire consumer electronics and computing industry to print really, really thin layers of semiconductors really near each. other. So they're trying to use and adapt that technology to also make quantum dots. Right. Because that technology is, they say, almost running into the physical limits of what you can print, right? Like they're starting to print circuits that are, you know, about this size where the

quantum effects are important or where, you know, you're laterally like stacking 10 atoms together. Yeah, they are really approaching the limit of this technology, which is really awesome. And it shows you like what humans can do, how innovative they can be when like really pressed to the limit and also when there are like billions of dollars at stake because the smaller your components, the faster your computer. And so like Intel and AMD and all these folks are really, really pushing hard on these technologies because there's literally rivers of money behind it. Yeah, there's billions of people who want a phone in their hands and their pockets. So the smaller you can get these chips, the more powerful they are. Yeah. And there's a lot of examples of when the

consumer industry pushes on something really, really hard. And then it turns out to be useful. for other things like physics research. For example, that same technology that you use to print circuits, we also use to print particle detectors at the large Hedron Collider. Those really thin layers of silicon can help you tell, oh, did an electron pass here, or did a muon pass there? Or was this weird kind of cork that passed through? So we can print very high-resolution detectors for our particles,

and we never could have developed that technology ourselves. It's only because billions were spent by the semiconductor industry to develop that technology. So now people are doing the same thing for making quantum dots. They're piggybacking on all those advances. You can print little quantum dots on a silicon chip. Yeah, exactly. So this is the direction they're going in for making qubits out of quantum dots, little devices that basically could be the elements of quantum computers.

Currently, the best quantum computers have only like 25, maybe 40 cubits, and they're done using atoms. But as we talked about previously, having atoms, in a trap, for example, is very unstable. It's very hard to get that and to keep it isolated and keep it from decohering, which is what you need to do to do the quantum computing. And so the idea is that this could be more stable. It's still in its early days and we don't have a quantum computer made out of qubits from

quantum dots in silicon that competes at all with the ones made from ions. But, you know, it's a promising avenue. So have they been able to do it? Have they been able to print quantum dots using silicon lithography? Yeah, they can print quantum dots. Oh, wow. So it's like around the corner then. Yeah, exactly. It's around the corner. And, you know, there's a bit of a definitional thing here. Basically, any very small piece of silicon is a quantum dot. And so in some respects, any time you get your silicon that small, it's a quantum dot. The question is, can you design it to be the quantum dot you want, right?

Right. I guess technically any dot is quantum. All dots are quantum. That's right. Even your Girl Scout cookie crumbs are quantum crumbs if they're small enough. Yeah, they're there and not there at the same time. All right, so you can maybe mix them in solution or print them on a silicon chip. You can also do something even kind of more interesting. Yeah, I think the funnest and craziest idea is to use viruses to assemble these things. What? Like not figurative viruses, but real viruses.

Real actual physical viruses. So these are things that like attack bacteria and get the bacteria to make more of themselves. But they can do more than just reproduce. They actually have like proteins on their surface that are little molecular machines that can do stuff. And the idea is that you find a virus that grabs onto your material. You can use it as like a little laborer, like a little worker to build yourself a crystal out of that material. Wait, so like viruses can grab and manipulate individual atoms? Yeah, absolutely.

I mean, viruses are super small and they have little proteins on them, right? And what is a protein, but basically a molecular little machine? And those proteins have surfaces on them that, bind to some things and not to other things like proteins, for example, cut and repair DNA. And DNA is just a string of molecules. And so we're talking about things at the same scale. And so the idea is that these viruses, you find ones that like to grab onto the molecule you want and you figure out a way to get the viruses to assemble in something like a regular pattern. That's the sort of mind-boggling part, is that the viruses aren't just all like all swimming around

each holding their piece of the quantum dot. They arrange themselves in something like a crystal pattern. So then the pieces of the quantum dot they're each holding click together to form the quantum dot. What? That's crazy. Have they actually done this? Is this like ongoing research? Yeah, this is ongoing research. They have actually done it. They haven't scaled it up, but it's something that really might work. You know, anytime you can like tap into the power of biology, we could never engineer something ourselves that way. But the way they take advantage of it is through evolution. They do this thing called phage display where they put a bunch of the material. they want the viruses to capture on a surface, and then they just wash viruses over it. And the ones that grab onto the surface are the ones they keep.

And then they breed those viruses together to make new viruses, and they do it again and again and again. And so they're like artificially selecting viruses that are good at this one thing. So basically breeding little viruses that can do our jobs for us. Wow. I mean, we all know how good we are in handling viruses. I know it does seem. As a civilization, what could go wrong, Danu?

What could go wrong exactly? Maybe they could bake our cookies for us. That's pretty interesting that you can maybe like kind of use viruses as little assembly robots. Yeah, little nano robots. I mean, rather than going to our engineers and saying, hey, could you build me a super tiny robot that's nanometers wide and can do this job? Just find one out there in nature and adapt it to your purpose. All right. Well, it sounds like you can build quantum dots.

I guess the hard part is getting them to do the things you want them to do or to like, you know, design them and make them to spec to take advantage of these interesting quantum properties. Yeah, if you want the quantum properties to do exactly what you want, you have to design them just right. You need exactly the right kind of, you know, gallium in there or cadmium in there to get just the kind of electron energy levels you need to accomplish what you're trying to accomplish.

All right, well, let's get into what quantum dots can do. What can they do for you, Daniel, besides, you know... Entertain and amaze. Yeah. Or give you taste your cookies. And maybe raise a virus army to take over the world. To make more cookies.

Oh, yeah, that's what I meant. That's what I meant. Or take over the world with cookies. You know, there's always a way. But for us, let's take a quick break. A foot washed up a shoe with some bones in it. They had no idea who it was. Most everything was burned up pretty good from the fire.

that not a whole lot was salvageable. These are the coldest of cold cases, but everything is about to change. Every case that is a cold case that has DNA. Right now in a backlog will be identified in our lifetime. A small lab in Texas is cracking the code on DNA. Using new scientific tools, they're finding clues in evidence so tiny you might just miss it.

He never thought he was going to get caught. And I just looked at my computer screen. And I was just like, ah, gotcha. On America's Crime Lab, we'll learn about victims and survivors. And you'll meet the team behind the scenes at Othrum, the Houston Lab that takes on the most hopeless cases to finally solve the unsolvable. Listen to America's Crime Lab on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. I'm Dr. Scott Barry Kaufman, host of the Psychology Podcast.

Here's a clip from an upcoming conversation about exciting. boring human potential. I was going to schools to try to teach kids these skills and I get eye rolling from teachers or I get students who would be like it's easier to punch someone in the face. When you think about emotion regulation, like you're not going to choose an adaptive strategy which is more effortful to use unless you think there's a good outcome as a result of it if it's going to be beneficial to you because it's easy to say like go you go blank yourself right? It's easy. It's easy to just drink the extra beer. It's easy to ignore to suppress Seeing a colleague who's bothering you and just, like, walk the other way.

Avoidance is easier. Ignoring is easier. Denial is easier. Drinking is easier. Yelling, screaming is easy. Complex problem solving. Meditating. You know, takes effort.

Listen to the psychology podcast on the IHartRadio app, Apple Podcasts, or wherever you get your podcasts. I always had to be so good, no one could ignore me. Carve my path with data and drive. but some people only see who I am on paper. The paper ceiling, the limitations from degree screens to stereotypes that are holding back over 70 million stars. Workers skilled through alternative routes rather than a bachelor's degree. It's time for skills to speak for themselves. Find resources for breaking through barriers at tailorpapersealing.org.

Brought to you by Opportunity at Work and the Ad Council. All right, quantum dots are going to take over the world, Daniel. They're going to improve our screen technology, apparently, and maybe a lot more. Because basically you can make quantum computers or you can kind of make designer atoms so that you can make things maybe that have special properties. Yeah. So what are some of the things that quantum dots can do? Well, the most important thing is that quantum dots can have sort of designer optical properties.

Remember that the reason that some things look a certain color, is because they reflect light of that color, which means they're absorbing all the other colors. So if you can design a material that absorbs light at certain frequencies and not other frequencies, you can basically design its color to be whatever you like. And if you want to design a very crisp display or you want a marker, you can inject into your experimental subject and watch as something flows around,

then you want to be able to design its optical properties. And so as you change the size of your quantum dot, for example, you change the energy that that electron can absorb, which changes how it looks optically. It kind of sounds like you're just making colors, though. Like, isn't that how color works usually? Like the atom in like a blue paint, reflect blue light especially? Yeah, that's exactly what we're trying to do. We're just making colors, but we're making very crisp, well-defined colors.

You want something which absorbs very, very narrowly or only reflects a very, very narrow range of frequencies. so it's like exactly blue or super duper perfect red or exactly the green you were looking for. I see. Quantum paint is the new marketing term. Yeah, exactly. And so this makes it,

if you're going to build a television, for example, it makes it much easier to get crisp colors. You know exactly how to combine your various little layers to get exactly the color you want on screen. So it's simpler. It's cheaper. It's more efficient. You don't need like, you know,

complicated filters. to get rid of the edge effects you didn't really want because you were forced to use the atoms that physics gave you, you can invent your own atoms to devise your own quantum screen. But can you make these quantum dots change the light or turn them on and off? How would this work? How would this television work? What would it be just a one image television?

I think each one is essentially like a filter. So you put some source of light behind a layer of red quantum dots and which you get our red light. Or if you put light behind a layer of green condom dots, you get green light or blue light. So it operates on the same basic principle as all your other televisions, which have, for example, blue LEDs or green LEDs or red LEDs, but this is the way that you get the pure light instead of all the white light. It'd be like super precise colors. That's the idea. Super precise colors, yeah.

Extra precise. And also, because they're more efficient, they show exactly the color you want, there's low. lower energy consumption. And so you can have like longer lifetimes. Cool. And that's the tricky part, I guess, is how you make them at the size of a television. Because you have to make a lot of them. You got to make a lot of them.

Yeah, exactly. And they have to survive. My kids dropping my phone, for example. They do. But, you know, because they can be sort of printed on anything and they're microscopic, they can potentially be used for things like, you know, rollable or flexible displays in the future. Cool.

All right, or like a blanket TV. Yeah, or a TV you could like fold up and, you know, stick in your pocket or something. Cool. All right, what else can we use quantum dots for? Another awesome application is in solar cells because, again, you can really tune the absorption and the emission. Then you can get quantum dots that absorb light at exactly the peak wavelength that you're seeing on your roof. You know, and so you can make sure that like the peak efficiency for absorption is where most of the light actually is. Right. Because right now it's kind of fuzzy. Yeah, exactly. It's kind of fuzzy. And

these solar cells are expensive to produce. But if you could get quantum dots ramped up so you could make a lot of them, you can make basically like solar power paint. And you could like have a solution with quantum dots in it that you basically paint onto a surface and it becomes a solar power cell. What? Like you can just paint your roof and then attach some wires to it and it's a solar panel. Yes, exactly. That is wild. Yeah, they would absorb the energy. and they would like chain themselves up so they can pass a current along. And so that would be pretty awesome. Like, you know how cool it is that you can paint like a chalkboard on a wall and it actually

kind of works? That's pretty cool. Well, this is like a step beyond that. It's like painting an electrical device onto your roof. Wow. Or anything, really, your car or your hat or really, you can get a tattoo. Can you get a solar cell tattoo, you know, inked on your skin? That would be awesome.

That would be awesome. And you can charge your phone just by a, against your body. Yeah, and the tattoo should look like a solar cell, right? That would be super cool. It looks like a solar cell and acts like a solar cell. Yeah, well, technically you could make it look like anything. Yeah, you could.

You can make it look like a rose or your grandma, and it would be helping you save some energy. That would be cool. It would power your phone. Yeah, cool. All right, so you can make solar paint? What else can you do with it? You can also use it in science.

A lot of biology uses something called biolabeling, where you like inject some substance into a, bacterium or into a larger animal and you want to follow like where did it go where is it being used where is the active site where it's like being actually processed so these quantum dots are like more stable and brighter than most of the other dies and so they're much more useful they can like last for months but they're also toxic aren't they yes they're poisonous I guess if you don't want your sample to live very long yeah a lot of them because you want to engineer particular optical properties require you to use various substances like cadmium, which is pretty toxic.

So we're not at a point where you want your kids eating a spoonful of quantum dots. Definitely not. But, you know, if you don't mind killing your bacteria to learn about how it's doing something or how it's defending itself, then it's all right. Oh, does that put a kibosh on the tattoos as well? What if you tattoo cadmium into your body? That would give you other kinds of cancer. Yes, not recommended yet.

But people are working on ways to make quantum dots. don't require cadmium or other toxic material. So I'm pretty sure that in the future we'll have human-save quantum dots. All right, cool. What else can we make with quantum dots? Well, we can also build super tiny electronics. You know about this material called graphene, which is basically like a lattice of carbon built in a super fancy,

interesting way that has fancy molecular properties. Well, graphene is really stable and really conductive, even when it's cut into super tiny devices, is like one nanometer wide. And so you can build like the tiniest of electronics using graphene single crystals, which are technically also quantum dots. Hmm.

Now you can make a circuit that's literally like one atom talks to another atom and then that atom talks to another atom. Yeah, exactly. And so this is like one potential way to even further miniaturize our electronics. Wow. But wouldn't it get quantum at that point? Or like would it still behave like a regular circuit?

It would get quantum, exactly. So you'd have to define it to do exactly what you want. But you can build transistors out of single atoms and single electron transistors are a thing you can do. The chemistry and the physics is a little bit different from the way we're currently doing electronics. But you can build the basic components we need for circuits out of these graphene single crystals. All right. But it sounds like maybe the technology that's pushing it, at least into the mainstream, is this idea of a quantum TV. So how far away are we from that?

Are they actually starting to make them or think about them or is Netflix investing on this? Yeah, quantum TVs are negative five years away, which means they've been on the market since about 2015. Why? What do you mean? Like you can put in money to buy a quantum TV 10 years in the future? No, that means five years ago, if you went on Amazon and typed in quantum LED, there were TVs for sale that you could purchase. You could go purchase a quantum LED TV right now. Oh, but it's not really made out of quantum dots, is it? No, it really has quantum dot technology. Oh, oh.

This is really a thing. Really? Wow. Okay, it's not a future technology. It's like five years ago technology. It's like Obama Year's technology. Exactly. Obama probably has a quantum TV and he's probably sitting in front of it eating quantum cookies right now.

Because yes, we can watch a quantum TV. Really? So if I buy a quantum TV, it has like quantum dots in it? Yeah, exactly. It has a quantum dot layer, which, filters is like LED backlight and helps reduce better colors. So like we were saying at the top of the program, quantum TVs are not a scam. They are real and they actually use quantum technology.

Unlike quantum yogurt and quantum hamsters and quantum massage and quantum stealth technology, this is real applications of quantum mechanics on your wall. Right, right. Although, you know, technically yogurt does have quantum particles in it. Everything tastes like particles in the end. It's good for your gut. All right, so have you seen a quantum TV? Does it look crisper and does it look nicer?

I think you should do some research, Ann. You'll maybe buy yourself a TV with your grant money. Yeah, maybe I will. You know, I did look up quantum TVs, but I can only watch a video of a quantum TV on my non-quantam screen. And so it doesn't really come through. It's like looking at a video of a high-definition television on your low-definition television.

It's not very impressive. So I've never actually seen one. And also the only clip you can watch is a clip of Scott Bacula in Quantum Leap, which doesn't help you. Yeah, they need to work on the quantum content, really. But no, I've never actually seen one in the wild. So any listeners out there that have a quantum screen write to us and let us know how awesome is it. Yeah, take a picture and send it to us to see how good it looks.

Take a quantum picture. Yeah. We'll get it and not get it at the same time. All right. Well, that's pretty cool that this technology is out there. It is being used on television. people are technically potentially watching Netflix right now with a quantum TV. I hope so.

Wow. All right. And it might potentially give some pretty amazing technologies in the future. That's right. With the power to understand the quantum world comes the ability to engineer it and have it do all sorts of things that normal atoms cannot do. So it's not just that physics is playing with the universe because we want to understand, but sometimes there are actual benefits for humanity.

Yeah. Yeah. Stay tuned for those quantum tattoos. Will every physicist get one just to, like, you know, show solidarity and team spirit? I don't think you could ever say every physicist will do anything except apply for grants. All right. Well, we hope you enjoyed that and we hope you look at the world a little bit different. Sometimes quantum technology and quantum effects are there for us to see and for us to binge watch with.

Well, thanks for joining us. See you next time. Thanks for listening, and remember that Daniel and Jorge Explain the Universe is a production of IHeartRadio. For more podcasts from IHeartRadio, visit the IHeartRadio app, Apple Podcasts, or wherever you listen to your favorite shows. Don't let biased algorithms or degree screens or exclusive professional networks or stereotypes. Don't let anything keep you from discovering the half of the workforce who are stars. Workers skilled through alternative routes rather than a bachelor's degree. It's time to tear the paper ceiling and see the stars beyond it.

Find out how you can make stars part of your talent strategy at tear the paper sealing.org. by opportunity at work in the ad council. Have you ever wished for a change but weren't sure how to make it? Maybe you felt stuck in a job, a place, or even a relationship. I'm Emily Tish Sussman, and on she pivots, I dive into the inspiring pivots of women who have taken big leaps in their lives and careers. I'm Gretchen Wittmer, Jody Sweetie. Monica Patton, Elaine Welteroth.

Learn how to get comfortable pivoting because your life is going to be full of them. Listen to these women and more on She Pivots. Now on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. I'm Simone Boyce, host of the Brightside podcast, and on this week's episode, I'm talking to Olympian, World Cup champion, and podcast host Ashlyn Harris. My worth is not wrapped up in how many things I've won, because what I came to realize is I valued winning so much that once it was over, I got the blues, and I was like, this is it. For me, it's the pursuit of greatness. It's the journey. It's the people. It's the people. people. It's the failures. It's the heartache. Listen to the bright side on the IHeart Radio app, Apple Podcasts, or wherever you get your

podcasts. This is an IHeart podcast.