Speaker 1: Hey, Daniel, I found another physics related scam recently. Oh
Speaker 1: did someone try to sell you quantum girl scott cookies? Again?
Speaker 1: Girls cut cookies do seem to quantum tunnel into my
Speaker 1: stomach pretty easily. I don't even have to eat him.
Speaker 1: So then, what's the scam? I saw an ad for
Speaker 1: a quantum television? Can you believe that? Nonsense? Actually? Wait,
Speaker 1: what do you mean? This is the real thing? What
Speaker 1: does the quantum TV do? Is it always fuzzy because
Speaker 1: of the uncertainty principle? Yeah, you know, the word quantum
Speaker 1: gets abused a lot, but this one time it's for real.
Speaker 1: It's not a scam. No, quantum televisions are a real thing,
Speaker 1: and they are extra crispy, just like a girl's Scout cookie.
Speaker 1: I am or Hammaye, cartoonists and the creator of PhD comics. Hi,
Speaker 1: I'm Daniel. I'm a particle of physicists, and I'm at
Speaker 1: least made out of girls Scout cookies. Oh wow, you're
Speaker 1: you're a big fan. It's for a good cause, you know,
Speaker 1: that's why I eat them. It's for a good cause.
Speaker 1: You know you can buy them and not eat them.
Speaker 1: What that would be offensive? You have to throw them
Speaker 1: in the trash, and you don't have to tell the
Speaker 1: girls cuts they would know. But welcome to our podcast.
Speaker 1: Daniel and Jorge Explain the Universe April, that kind of
Speaker 1: irt radio in which we take our cookie fueled brains
Speaker 1: and try to understand everything about the universe, not just
Speaker 1: the tiny quantum particles and the crazy stuff happening in
Speaker 1: the center of stars, but everything in between. We take
Speaker 1: that immense mental journey all the way out into the
Speaker 1: universe and back into the quantum particles and explain all
Speaker 1: of it to you. Yeah, do you have a favorite
Speaker 1: girl Scout cookies? Daniel? Oh, we're getting real here, huh.
Speaker 1: I'm not gonna endorse one particular Girls Scott Cookies. I
Speaker 1: gotta go. I think with the classic than mint. You know,
Speaker 1: It's just it's so easy for them to tunnel into
Speaker 1: your stomach. My spouse would be appalled at the mixing
Speaker 1: of mint and chocolate. Do this taste like toothpaste to her? Yeah?
Speaker 1: With chocolate. There's probably a reason there's no chocolate toothpaste flavor.
Speaker 1: But there are a lot of interesting and amazing things
Speaker 1: in this universe that we like to talk about in
Speaker 1: this podcast. Things that are out there in the vast
Speaker 1: reaches of space, and also things that are right here
Speaker 1: at home, and things that are maybe at the tip
Speaker 1: of your fingertip without even knowing. Yes, things that are
Speaker 1: harder to understand even then, the combination of herbs and chocolate,
Speaker 1: things that are weird, things that are quantum, things that
Speaker 1: make no sense but are actually real. Yeah, because physics
Speaker 1: reveals that the universe is a pretty weird place. It
Speaker 1: doesn't always work the same way that we grew up
Speaker 1: thinking that it worked. There's all kinds of strange things
Speaker 1: going on, especially at the microscopic and at the quantum level. Yeah,
Speaker 1: that's basically the job of physics is to figure out
Speaker 1: how does the world actually work, Not the way we
Speaker 1: thought it should work, or the way we might have
Speaker 1: imagined it worked from our experience with rivers and rocks
Speaker 1: and stuff, but the way fundamentally things actually happen. And
Speaker 1: sometimes that's just for our edification, just to know how
Speaker 1: the universe actually works. But sometimes it's actually useful and
Speaker 1: we can use it to build cool new stuff. Wait,
Speaker 1: what physics can be useful? Who told you that? Some
Speaker 1: physicists your parents, some physicist After he told me some cookies.
Speaker 1: Oh right, right, a limit or professional limit to being
Speaker 1: a girl scout. You've never had a physics scott cookie?
Speaker 1: Does it taste like particles? I hear the Higgs boson
Speaker 1: is pretty tasty. Everything tastes like particles, man, everything particles.
Speaker 1: Particles are also the only things doing any tasting. Yeah,
Speaker 1: you're saying that physics can be useful. Physics can be useful. Yes.
Speaker 1: In fact, you know, the Worldwide Web was invented at
Speaker 1: a particle physics laboratory, and all sorts of things come
Speaker 1: out of just like gaining knowledge about how the universe works, right,
Speaker 1: And we all know how useful the Worldwide Web is.
Speaker 1: That's right. It's contributed to a huge decrease in productivity worldwide.
Speaker 1: It's like an anti useful particle there, depends on your
Speaker 1: goals man of reducing work. But yeah, well I do
Speaker 1: admit this useful to know physics, for sure, and sometimes
Speaker 1: we can use that knowledge to build amazing and and
Speaker 1: cool things that we couldn't do before. And that includes
Speaker 1: maybe quantum mechanics, which is like the weirdest and most
Speaker 1: awesomest thing in the universe. It is, and our understanding
Speaker 1: quantum mechanics underlies most modern electronics. It's the reason that
Speaker 1: your phone works, it's the reason your computer boots up.
Speaker 1: It's also the reason your computer crashes. I guess no,
Speaker 1: that's the fault of the girls got cookie crumples that
Speaker 1: fell in my keywork. It's like a physical virus infecting
Speaker 1: your computer. Yeah, quantum mechanics helps us not just kind
Speaker 1: of understand what's happening with our electronics and everything around us,
Speaker 1: but you can actually use some of these weird quantum
Speaker 1: effects to do interesting things like microscopes, right, like electric microscopes.
Speaker 1: They work on quantum mechanical principles. Yeah. Basically, everything that
Speaker 1: works at the very small scale that uses one or
Speaker 1: two or small set of particles has to follow quantum rules.
Speaker 1: So anything that's been super miniaturized or uses particles to
Speaker 1: look at super tiny stuff has to follow quantum rules.
Speaker 1: And sometimes those quantum rules are different in a really
Speaker 1: useful way. Yeah. And usually this kind of technology is
Speaker 1: limited to physics labs and engineering labs and research centers.
Speaker 1: But soon quantum mechanics technology might be coming to your home.
Speaker 1: That's right, Get ready to buy quantum cookies, I mean
Speaker 1: quantum TVs you know, there is actually something quantized by cookies.
Speaker 1: You notice how you can't eat one and a half
Speaker 1: cookies or three in a quarters cookies. It's always like
Speaker 1: into your numbers of cookies. Oh my god, you just
Speaker 1: discovered the whites and quantum cookie principle. I did a
Speaker 1: lot of experiments. It's more of a social science principle though. Yeah,
Speaker 1: it's a bit of a soft science there. Cookies, I
Speaker 1: get the software my sciences and your stomach and your
Speaker 1: body exactly. Well. There there is now a proposed quantum
Speaker 1: television technology and it's based on kind of a and
Speaker 1: not a new technology, but a technology that's been around
Speaker 1: for a while in quantum mechanics. Yeah, this is really
Speaker 1: fascinating idea that lets us build something like artificial atoms
Speaker 1: and manipulate electron energy levels to get all sorts of
Speaker 1: fascinating properties that we could use for really a wide
Speaker 1: range of possible technologies. So to be on the program,
Speaker 1: we'll be talking about what are quantum dots? That does
Speaker 1: sound like a girl's got a very very small cookie,
Speaker 1: the quantum dot. You know, someone what is it? Thin
Speaker 1: min's and snickerdoodles and quantum dots? But how many quantum
Speaker 1: dots would be in one box of cookies, right, like
Speaker 1: ten to twenty six. That's a pretty good deal, mom,
Speaker 1: I only had ten of the twelve quantum dot cookies
Speaker 1: for dessert. That's your alignment for the rest of your life.
Speaker 1: So when you heard the phrase quantum dot, did you
Speaker 1: think it was another one of these ridiculous schemes. Yeah,
Speaker 1: I'd heard of him before. I just never knew what
Speaker 1: they are. I mean, I imagine they're just really small
Speaker 1: dots at the quantum level. But you know, is it
Speaker 1: like a dot of ink, dot of what? It's a
Speaker 1: dot of quantum? Right, pure quantum? All right? Well, as usual,
Speaker 1: Daniel went out there into the wild of the Internet
Speaker 1: to ask people if they knew what quantum dots are.
Speaker 1: So thank you to everyone who broke through their inhibitions
Speaker 1: and answered these random questions without any research. If you
Speaker 1: would like to participate in the future, please write to
Speaker 1: me at questions at Daniel and Jorge dot com. Yes,
Speaker 1: I think about it for a second. Is so, when
Speaker 1: asked you what a quantum dot is, what would you answer?
Speaker 1: Here's what people had to say. I think a quantum
Speaker 1: dot refers to a single particle such as an electron
Speaker 1: that is isolated by means of electromagnetic fields. The particle
Speaker 1: is confined to a small region in space, so it
Speaker 1: has a very high um kinetic energy. Okay, I think
Speaker 1: quantum dots are really small collections of atoms. Believe often
Speaker 1: it's um for gold atoms to lump together. Maybe if
Speaker 1: the idea that like the universe is pixelated, maybe quantum
Speaker 1: dots are there, the grid points that underly everything. If
Speaker 1: I had guess, I would say quantum dots are maybe
Speaker 1: something like string theory, where if we break things down
Speaker 1: as small as we can get, we're we're stuck with
Speaker 1: these quantum dots, and and they can be the building
Speaker 1: blocks for a lot of quantum things. I think, or
Speaker 1: he said it once. The word quantum just goes in
Speaker 1: front of anything these days. It seems like I don't
Speaker 1: know for sure, but I think it might refer to
Speaker 1: the mathematical concept of a um particle that doesn't have
Speaker 1: a volume, so it only has coordinates, but not volume
Speaker 1: in space or zero volume. Quantum it's something small and
Speaker 1: a dot. It's something small also, so quantum dot. Probably
Speaker 1: you'll find it in at the end of a quantum sentence,
Speaker 1: how about it. So, I've never actually heard the phrase
Speaker 1: quantum dots before. My guess is that it has to
Speaker 1: do with the idea of that space itself is quantized,
Speaker 1: and that if you were able to zoom in far enough,
Speaker 1: there would be a smallest possible point. I've never ever
Speaker 1: heard of a quantum dotum afraid. I'm guessing they have
Speaker 1: something to do with the idea that space is quantized,
Speaker 1: so like pixels on a display. All right, not a
Speaker 1: lot of people know what a quantum dot is, apparently no.
Speaker 1: But there are some really nice speculations here, like the
Speaker 1: math concept of a particle with no volume. That's definitely
Speaker 1: something we've talked about in the podcast. I guess everything
Speaker 1: is a quantum dot technically, right, like all particles are
Speaker 1: just the point particles. Was the difference between a dot
Speaker 1: and a point, Daniel get philosophical? One of them has
Speaker 1: mint in it, I guess, and the other one doesn't.
Speaker 1: I have no idea. I have no idea when it's round,
Speaker 1: maybe the other one is pointing. Maybe yeah, I don't know.
Speaker 1: A point, technically speaking, is a single value in space,
Speaker 1: whereas I guess a dot could have some width to it.
Speaker 1: You have a good point that dot. All right, let's
Speaker 1: jump into it. Daniel, what is the quantum dot? Settle
Speaker 1: this for us? Yeah, quantum dot is really fascinating. It's
Speaker 1: basically just a piece of semi conductor, but a very
Speaker 1: very very small piece, so you get interesting quantum effects
Speaker 1: because semiconductors are sort of very flexible electrically and can
Speaker 1: be manipulated by doping and adding different kinds of materials.
Speaker 1: You can essentially construct any kind of energy levels you
Speaker 1: want for your electron, which is really what determines the
Speaker 1: sort of like bulk properties of a material. So it's
Speaker 1: just a really really tiny piece of anything, right, doesn't
Speaker 1: have you a semiconductor. It can be any material that
Speaker 1: you can call it a quantum dot. Yeah, it could
Speaker 1: be any material, but we typically use semiconductors because of
Speaker 1: their interesting electrical properties. And so take some piece of
Speaker 1: material and make a really really small version of it,
Speaker 1: and then quantum effects take over. Things like the electron,
Speaker 1: for example, gets trapped in your quantum dot, and then
Speaker 1: the width of it is now important to how of
Speaker 1: that electron behaves. It changes like the energy levels the
Speaker 1: electron can have, which changes like how it absorbs light
Speaker 1: or a midst light or conducts electricity. How big are
Speaker 1: we talking about or how small are we talking about?
Speaker 1: These quantum dots being like how many nanometers we're talking
Speaker 1: about like one to ten nanometers in size. These are
Speaker 1: really tiny, Like you could line up a million of
Speaker 1: these things across your finger. They're super duper small, and
Speaker 1: they have to be small in order to get to
Speaker 1: the quantum effects, right, they have to be basically on
Speaker 1: the quantum scale, the Antman scale, so one to ten nanometers.
Speaker 1: And how does that compare it to like the you know,
Speaker 1: the quote unquote with of an atom. It's about ten
Speaker 1: or fifteen times wider than like the hydrogen atom is
Speaker 1: defined by like you know, the cloud of electrons around
Speaker 1: the nucleus. So you're definitely getting down to that scale.
Speaker 1: And I think that's sort of the key idea is
Speaker 1: that you know, when you get electrons down to this
Speaker 1: really small scale, like the size of a hydrogen atom
Speaker 1: or what happens in atoms, they start to exhibit these
Speaker 1: quantum properties, like having very specific energy levels that only
Speaker 1: happens when you can strain an electron m all right,
Speaker 1: So you know it's like maybe ten atoms wide these dots,
Speaker 1: and are they actually like dots? Are they like cubes?
Speaker 1: Are they like little balls? Do we have pictures of them?
Speaker 1: We do have pictures of them. Usually they're little crystals.
Speaker 1: And it depends a little bit on how they are
Speaker 1: built and how their fabricatum. And we'll get into it
Speaker 1: in a minute about how you make these things. And
Speaker 1: you can make them in almost any shape. You can
Speaker 1: make cubes, you can make pyramids, you can make you know,
Speaker 1: diamond shapes, whatever you like. And the shape of the
Speaker 1: nanocrystals changes how the electron is sort of capture it
Speaker 1: in it and can change its behavior. So depending on
Speaker 1: what you want for its electrical properties, you might design
Speaker 1: a different shape. M M. All right, So it's almost
Speaker 1: like you're kind of making an atom, almost. Yeah. The
Speaker 1: key idea here is that when you look at the
Speaker 1: periodic table, you see lots of different elements, and those
Speaker 1: elements all have really different properties, right, Some of them
Speaker 1: conduct a lot of electricity, some of them are really interactive,
Speaker 1: and some of them are not. All of those properties
Speaker 1: come from behavior of the electrons and their energy levels,
Speaker 1: like are those electron orbitals filled? And how big are they? Etcetera, etcetera.
Speaker 1: But we're sort of limited to the atoms that we
Speaker 1: have in nature. You know, if you want an atom
Speaker 1: that does a specific kind of thing that emits light
Speaker 1: of a certain frequency or absorbs light of a certain frequency,
Speaker 1: you sort of have to pick from the menu that
Speaker 1: we have until now. Because quantum dots allow you to
Speaker 1: basically engineer electron energy levels to say, I'd like electron
Speaker 1: energy levels that look like this, so you can have
Speaker 1: whatever whatever property. That's why they're sometimes called artificial atoms.
Speaker 1: They don't have a nucleus and electrons around them, but
Speaker 1: they have that sort of property of an atom that
Speaker 1: they're controlled by their electron energy levels. Interesting, they're like
Speaker 1: designer atoms, yes, exactly, designer atoms like made to order. Yeah,
Speaker 1: And so if we want a material that does something
Speaker 1: that no natural material does, then we can maybe build
Speaker 1: it out of quantum dots or design quantum dots that
Speaker 1: have that specific ability. What kinds of abilities are we
Speaker 1: talking about, like reflecting light or like conduct or how
Speaker 1: easy they give off an electron or or how they taste.
Speaker 1: I would not recommend eating any of these quantum dots.
Speaker 1: Almost all of them are totally toxic. But yeah, they
Speaker 1: have interesting optical properties, like they can absorb light at
Speaker 1: whatever frequency you want, you know, and they can give
Speaker 1: off light at whatever frequencies you want, which is very
Speaker 1: helpful for example and making a very crisp display for
Speaker 1: your television, and other kinds of things like absorbing power
Speaker 1: for solar cells. And there's another aspect to it, which
Speaker 1: is maybe less practical but more fascinating, which is that
Speaker 1: you can sort of design quantum behaviors. Previously, when people
Speaker 1: wanted to do quantum experiments, it was hard because you
Speaker 1: had to use like actual atoms that we find in nature,
Speaker 1: and those atoms going to be difficult to deal with.
Speaker 1: You have to like have a vacuum system and lasers
Speaker 1: to capture it. Remember we talked about Bose Einstein contensate.
Speaker 1: It's a difficult thing to do because it has to
Speaker 1: be done with atoms and all these complex systems. Yeah,
Speaker 1: I lose my atoms all the time. They're slippery, they
Speaker 1: are slip bury and it's a pain and it's expensive.
Speaker 1: But if you could do it with quantum dots, they're
Speaker 1: much easier to manufacture. You might even be able to
Speaker 1: print them on chips for example, So you could do
Speaker 1: all sorts of fascinating quantum experiments without all the expensive machinery.
Speaker 1: Could you print like a quantum computer out of quantum dots? Yes, exactly,
Speaker 1: that's one direction. People are going trying to build cubits
Speaker 1: out of quantum dots. But doesn't the quantum no iss
Speaker 1: of something always decrease the more atoms you get, Like
Speaker 1: if you have ten atoms, that's usually sort of like
Speaker 1: less quantumy than one atom. Right, you can worry about
Speaker 1: like decoherence effects. As it interacts with its environment, it
Speaker 1: loses some of those quantum effects because the wave functions decohere.
Speaker 1: And that's something that's really difficult to do with atoms
Speaker 1: because it's hard to isolate them from the system. Right,
Speaker 1: The key is isolation. You could have a really large
Speaker 1: system that doesn't deco here as long as it remains
Speaker 1: isolated from the environment. That's hard to do with atoms
Speaker 1: because you know, they bounce around and they jiggle and stuff.
Speaker 1: But quantum dots are sort of easier to localize. And
Speaker 1: if we're easier to isolate, is the idea, Oh man,
Speaker 1: are we going to go back to dot matrix printers,
Speaker 1: but this time there will be quantum dot matrix printers. Yeah,
Speaker 1: exactly is that? What is that our featured again, and
Speaker 1: then we'll go back to quantum motives too, but it
Speaker 1: will be the quantum version of those sounds. It would
Speaker 1: be much spookier, sound cooler, which is by definition. And
Speaker 1: something that's really fascinating about these things is that they're
Speaker 1: offering referred to as zero dimensional objects, of course, because
Speaker 1: that's not confusing, and that was really confusing for me
Speaker 1: when I first was reading about that, because you know,
Speaker 1: I'm three dimensional, there's forward, backwards, side to side, and
Speaker 1: up and down. I'm defined by three different dimensions, and
Speaker 1: you can imagine, you know, a sheet of paper is
Speaker 1: almost two dimensional, and like a thin piece of string
Speaker 1: is like almost one dimensional. What's a zero dimensional object?
Speaker 1: And it's really something where it can't go anywhere, So
Speaker 1: it's really like a point in space us. There are
Speaker 1: electrons in there, and yes, technically they can move a
Speaker 1: little bit sideways, but really they're constrained and the only
Speaker 1: way they can move is sort of up and down
Speaker 1: in energy. Oh interesting, almost like a perfect box for electrons. Yeah,
Speaker 1: it's a perfect little box for electrons. And you know,
Speaker 1: quantum mechanically, the way the electron behaves is completely defined
Speaker 1: by the shape of the box. Like an electron just
Speaker 1: floating through space is not actually quantized like you could
Speaker 1: have any energy level. Free electrons are not quantized at all.
Speaker 1: The quantization only happens when you constrain it, when you
Speaker 1: say you gotta live in this little box or whizz
Speaker 1: around this nucleus of the atom. That's where the quantization
Speaker 1: comes from. And so here, by constructing your own box,
Speaker 1: you define your own energy levels for the electron, which
Speaker 1: I think is pretty cool. So we're like quantum designers. Wow,
Speaker 1: And this is an idea from the eighties. It was
Speaker 1: made a long time ago, but only now maybe we're
Speaker 1: getting into how to actually use these thoughts. Yeah, exactly.
Speaker 1: The idea has been around for a few decades, and
Speaker 1: the proof of principle was done in the eighties. But
Speaker 1: with lots of things, it's only really useful if you
Speaker 1: can make a lot of them, and if you can
Speaker 1: make them at less than like a billion dollars per dot. Right,
Speaker 1: All right, well, let's get into how you actually make
Speaker 1: a quantum dot and what can you do with them.
Speaker 1: But first let's take a quick break. All right, we're
Speaker 1: talking about quantum dots, which are not girls cout cookies,
Speaker 1: but possibly TVs in the future, yes, TVs, maybe even
Speaker 1: in your present. They might end up on our phones. Yeah,
Speaker 1: you could have a quantum dots screen. They could create
Speaker 1: screens that are like really flexible. You can like a
Speaker 1: roll up in the stuff in your pocket. Just don't
Speaker 1: eat them. Do not eat quantum screens, all right. Quantum
Speaker 1: dot is a little tiny piece of semiconductor, maybe one
Speaker 1: to ten nanometers wide, which is about like ten atoms
Speaker 1: in with and they can act like little niner atoms.
Speaker 1: They can trap electrons and you can make them sit
Speaker 1: at whatever energy levels you want. Yeah, you can make
Speaker 1: the particles dance whatever dance you tell them to. All right,
Speaker 1: So I guess the question is how do you make them?
Speaker 1: How do you make a quantum dot? Do you just
Speaker 1: like spray some quantumness and they form in the air.
Speaker 1: What's the formative? Yeah, it's one teaspoon of quantumness to
Speaker 1: teaspoons of dot and then just mix. There you go.
Speaker 1: It's hard, right, and this is one of the challenges.
Speaker 1: And so there are a lot of different approaches to
Speaker 1: making these quantum dots, and we'll see which one sort
Speaker 1: of takes off for various applications. There's basically three totally
Speaker 1: different approaches. One is chemical, so basically just try to
Speaker 1: mix these things like we were just joking about, but
Speaker 1: for real. And the idea is that these things are crystals,
Speaker 1: which means that in some sense they should self assemble,
Speaker 1: you know, the way like crystals will form themselves. If
Speaker 1: you put salt into solution and you shake it, the
Speaker 1: salt should come out of the solution, you know, make
Speaker 1: these crystals. And so you do the same thing with
Speaker 1: the kind of quantum dot you want to make. Whatever
Speaker 1: it is you're trying to build, maybe it's mostly silicon,
Speaker 1: maybe it has other stuff in it. You put all
Speaker 1: those ingredients into some solution, you heat it up so
Speaker 1: it all like breaks up into a big soup, and
Speaker 1: then you hope that nanocrystals get nucleated and then sort
Speaker 1: of build on themselves. But then they would be floating
Speaker 1: around or they would kind of form on your surface. No,
Speaker 1: then they would be floating around exactly, and then you
Speaker 1: need to do something to like pull them out and
Speaker 1: you know, make them useful somehow. But often you want
Speaker 1: them in solution, like maybe you want them suspended in
Speaker 1: water so they can glow a certain temperature where you
Speaker 1: can inject them into your experiment or whatever. Sounds kind
Speaker 1: of tricky. It's pretty tricky, and also it's tricky to
Speaker 1: filter them, right. You want only quantum dots that have
Speaker 1: formed well, and so this process isn't always going to
Speaker 1: form you high quality quantum dots every single time, and
Speaker 1: so it's tricky to get exactly the right ones out.
Speaker 1: And so people have tried all sorts of variations on
Speaker 1: this approach, like using molecular seating, you know, starting with
Speaker 1: something that has sort of like the right shape to
Speaker 1: nucleate those crystals and encourage things to form just the
Speaker 1: right way. It's really complex, sort of like as a
Speaker 1: chemistry problem. You know, how do you get all these
Speaker 1: molecules bouncing around in solution to come together and like
Speaker 1: build themselves out of these mini legos? Right? Yeah, sounds tricky.
Speaker 1: What are other ways that you can make them? Another
Speaker 1: way is basically following the principles of semiconductor technologies, which
Speaker 1: have come really really far in printing tiny circuits. The
Speaker 1: way your computer is build is not by super tiny
Speaker 1: little fingers soldering together little components individually, right, it's printed
Speaker 1: onto a sheet of silk and in a super duper
Speaker 1: tiny way. So they have developed this technology because it
Speaker 1: underpins the entire consumer electronics and computing industry to print
Speaker 1: really really thin layers of semi conductors really near each other.
Speaker 1: So they're trying to use and adapt that technology to
Speaker 1: also make quantum dots, right, because that technology is they say,
Speaker 1: almost running into the physical limits of how what you
Speaker 1: can print, right, like the starting to print circuits that
Speaker 1: are you know, about this size where the quantum effects
Speaker 1: are important, or where you know, you're literally like stacking
Speaker 1: ten atoms together. Yeah, they are really approaching the limit
Speaker 1: of this technology, which is really awesome and it shows
Speaker 1: you like what humans can do, how innovative they can
Speaker 1: be when like really pressed to the limit. And also
Speaker 1: when there are like billions of dollars at stake, because
Speaker 1: the smaller your components, the faster your computer, and so
Speaker 1: like Intel and a m D and all these folks
Speaker 1: are really really pushing hard on these technologies because there's
Speaker 1: literally rivers of money behind it. Yeah, there's a billions
Speaker 1: of people who want to phone in their hands and
Speaker 1: their pockets, and so the smaller you can get these
Speaker 1: chips to the more powerful they are. Yeah, and there's
Speaker 1: a lot of examples of when the consumer industry pushes
Speaker 1: on something really, really hard, and then it turns out
Speaker 1: to be useful for other things like physics research. For example,
Speaker 1: that same technology that you use to print circuits, we
Speaker 1: also used to print particle detectors at the large Hadron collider.
Speaker 1: Those really thin layers of silicon can help you tell, oh,
Speaker 1: did an electron pass here, or did a muan pass there,
Speaker 1: or was this weird kind of cork that passed through.
Speaker 1: So we can print very high resolution detectors for our particles,
Speaker 1: and we can never could have developed that technology ourselves.
Speaker 1: It's only because billions were spent by the semiconductor industry
Speaker 1: to develop that technology. So now people are doing the
Speaker 1: same thing for making quantum dots. They're pigging backing on
Speaker 1: all those advances, like you can print little quantum dots
Speaker 1: on a silicon chip. Yeah, exactly, So this is the
Speaker 1: direction that they're going and for making cubits out of
Speaker 1: quantum dots, little devices that basically could be the elements
Speaker 1: of quantum computers. Currently, the best quantum computers have only
Speaker 1: like twenty five maybe fortuits, and they're done using atoms.
Speaker 1: But as we talked about previously, having atoms in a trap,
Speaker 1: for example, is very unstable. It's very hard to get
Speaker 1: that and to keep it isolated and keep it from
Speaker 1: deco hearing, which is what you need to do to
Speaker 1: do the quantum computing. And so the idea is that
Speaker 1: this could be more stable. It's still in its early
Speaker 1: days and we don't have a quantum computer made out
Speaker 1: of cubits from quantum dots and silicon that competes at
Speaker 1: all with the ones made from ions. But you know,
Speaker 1: it's a promising avenue. So have they been able to
Speaker 1: do it? Have they been able to print quantum dots
Speaker 1: using silicon lithography? Yeah, they can print quantum dots. Wow.
Speaker 1: So it's like around the corner then, yeah, exactly, it's
Speaker 1: around the corner. And you know, there's a bit of
Speaker 1: a definitional thing here. Basically, any very small piece of
Speaker 1: silicon is a quantum dot. And so in some respects,
Speaker 1: anytime you get your silicon that's small, it's a quantum dot.
Speaker 1: The question is can you design it to be the
Speaker 1: quantum dot you want? Right? Right? I guess technically any
Speaker 1: dot is quantum. All dots are quantum. That's right. Even
Speaker 1: your girls got cookie crumbs are quantum crumbs if they're
Speaker 1: small enough. Yeah, they're there and not there at the
Speaker 1: same time, all right, So you can maybe mix them
Speaker 1: in solution or print them on a silicon chip. You
Speaker 1: can also do something even kind of more interesting. Yeah,
Speaker 1: I think the funnest and craziest idea is to use
Speaker 1: viruses to assemble these things. What like yeah, like not
Speaker 1: the figurative viruses, but real viruses, real actual physical viruses.
Speaker 1: So these are things that like attack bacteria and get
Speaker 1: the bacteria to make more of themselves. But they can
Speaker 1: do more than just reproduce. They actually have like proteins
Speaker 1: on their surface that are little molecular machines that can
Speaker 1: do stuff. And the idea is that you find a
Speaker 1: virus that grabs onto your material, you can use it
Speaker 1: as like a little laborer, like a little worker, to
Speaker 1: build yourself a crystal out of that material. Wait, so
Speaker 1: like viruses can grab and manipulate individual atoms. Yeah, absolutely,
Speaker 1: I mean viruses are super small and they have little
Speaker 1: proteins on them, right, And what is a protein but
Speaker 1: basically a molecular little machine and those proteins have surfaces
Speaker 1: on them that buying to some things and not to
Speaker 1: other things. Like proteins for example, cut and repair DNA
Speaker 1: and DNA is just a string of molecules, and so
Speaker 1: we're talking about things at the same scale. And so
Speaker 1: the idea is that these viruses, you find ones that
Speaker 1: like to grab onto the molecule you want, and you
Speaker 1: figure out a way to get the viruses to assemble
Speaker 1: in something like a regular pattern. That's the sort of
Speaker 1: mind boggling party that the viruses aren't just all like
Speaker 1: all swim around, each holding their piece of the quantum dot.
Speaker 1: They arrange themselves in something like a crystal pattern. So
Speaker 1: then the pieces of the quantum dot there each holding
Speaker 1: click together to form the quantum dot. What that's crazy?
Speaker 1: Have they actually done? This is is like ongoing research. Yeah,
Speaker 1: this is ongoing research. They have actually done it. They
Speaker 1: haven't scaled it up, but it's something that really might work.
Speaker 1: You know, anytime you can like tap into the power
Speaker 1: of biology. We could never engineer something ourselves that way.
Speaker 1: But the way they take advantage of it is through evolution.
Speaker 1: They do this thing called phage display where they put
Speaker 1: a bunch of the material they want the viruses to
Speaker 1: capture on a surface, and then they just wash viruses
Speaker 1: over it, and the ones that grab onto the surface
Speaker 1: are the ones they keep. And then they breathe those
Speaker 1: viruses together to make new viruses, and they do it
Speaker 1: again and again and again, and so they're like artificially
Speaker 1: selecting viruses that are good at this one. So basically
Speaker 1: breeding little viruses that can do our jobs for us. Wow,
Speaker 1: I mean, we all know how good we are at
Speaker 1: handling viruses. It does seem as a civilization, what could
Speaker 1: go wrong, Daniel, What could go wrong? Exactly? Maybe they
Speaker 1: could bake our cookies for us. That's pretty interesting that
Speaker 1: you can maybe like kind of use viruses as little
Speaker 1: assembly robots. Yeah, little nano robots. I mean, rather than
Speaker 1: going to our engineers and saying, hey, could you build
Speaker 1: me a super tinier robot that's nanometers wide and can
Speaker 1: do this job, just find one out there in nature
Speaker 1: and adapt it to your purpose. Al Right, Well, it
Speaker 1: sounds like you can build quantum dots. I guess is
Speaker 1: the hard part is getting them to do the things
Speaker 1: you want them to do, or to like, you know,
Speaker 1: design them and make them to spect to take advantage
Speaker 1: of these interesting quantum properties. Yeah, if you want the
Speaker 1: quantum properties to do exactly what you want, you have
Speaker 1: to design them just right. You need exactly the right
Speaker 1: kind of you know, gallium in their academy um in
Speaker 1: there to get just the kind of electron energy levels
Speaker 1: you need to accomplish what you're trying to accomplish. All right, well,
Speaker 1: let's get into what quantum dots can do. What can
Speaker 1: they do for you, Daniel? Besides you know, entertain enemies
Speaker 1: or give you taste your cookies and maybe raise a
Speaker 1: virus army to take over the world to make more cookies.
Speaker 1: Oh yeah, that's what I meant. That's what I meant.
Speaker 1: Or take over the world with cookies. You know, there's
Speaker 1: always a way. But for us, let's take a quick break.
Speaker 1: All right, quantum dots are gonna take over the world, Daniel.
Speaker 1: They're gonna improve our screen technology apparently, and maybe a
Speaker 1: lot more because basically you can make quantum computers, or
Speaker 1: you can kind of make designer atoms so that you
Speaker 1: can make things maybe that has special properties. Yeah, So
Speaker 1: what are some of the things that them dots can do? Well,
Speaker 1: the most important thing is that quantum dots can have
Speaker 1: sort of designer optical properties. Remember that the reason that
Speaker 1: some things look a certain color is because they reflect
Speaker 1: light of that color, which means they're absorbing all the
Speaker 1: other colors. So if you can design a material that
Speaker 1: absorbs light at certain frequencies and other frequencies, you can
Speaker 1: basically design its color to be whatever you like. And
Speaker 1: if you want to design a very crisp display or
Speaker 1: you want to marker, you can inject into your experimental
Speaker 1: subject and watch as something flows around. Then you want
Speaker 1: to be able to design its optical properties. And so
Speaker 1: as you change the size of your quantum dot, for example,
Speaker 1: you change the energy that that electron can absorb, which
Speaker 1: changes how it looks optically. It's kind of sounds like
Speaker 1: you're just making colors, though, Like isn't that how color works? Usually,
Speaker 1: like the atom in like a blue paint reflect blue
Speaker 1: light especially. Yeah, that's exactly what we're trying to do.
Speaker 1: We're just making colors, but we're making very crisp, well
Speaker 1: the fine colors, right. You want something which absorbs very
Speaker 1: very narrowly or only reflects a very very narrow range
Speaker 1: of frequencies. So it's like exactly blue or super duper
Speaker 1: perfect red or exactly the green you were looking for.
Speaker 1: I see quantum paint is the new marketing term. Yeah, exactly.
Speaker 1: And so this makes it if you're going to build
Speaker 1: a television, for example, it makes it much easier to
Speaker 1: get crisp colors. You know exactly how to combine your
Speaker 1: various little layers to get exactly the color you want
Speaker 1: on screen. So it's simpler, it's cheaper, it's more efficient.
Speaker 1: You don't need, like, you know, complicated filters to get
Speaker 1: rid of the edge effects that you didn't really want
Speaker 1: because you were forced to use the atoms that physics
Speaker 1: gave you. You You can invent your own atoms to devise
Speaker 1: your own quantum screen. But can you make these quantum
Speaker 1: dots change the light or turn them on and off?
Speaker 1: How would this work? How would this television work? Would
Speaker 1: it be just a one image television? I think each
Speaker 1: one is essentially like a filter. So you put some
Speaker 1: source of light behind a layer of red quantum dots,
Speaker 1: and which you get our red light. Or if you
Speaker 1: put light behind the layer of green condom dots, you
Speaker 1: get green light or blue light. So it operates on
Speaker 1: the same basic principle as all your other televisions, which
Speaker 1: have for example blue LEDs or green l e d
Speaker 1: s or red l e d s. But this is
Speaker 1: the way that you get the pure light instead of
Speaker 1: all the white light. Be like super precise colors. That's
Speaker 1: the idea. Super precise colors. Yeah, extra precise, extra precise.
Speaker 1: And also because they're more efficient they show exactly the
Speaker 1: color you want, there's lower energy consumption and so you
Speaker 1: can have like longer lifetimes. And that's the turkey part,
Speaker 1: I guess is how you make them at the size
Speaker 1: of a television because you have to make a lot
Speaker 1: of them. You've got to make a lot of them
Speaker 1: yet exactly, and they have to survive my kids dropping
Speaker 1: my phone for example. They do. But you know, because
Speaker 1: they can be sort of printed on anything in their
Speaker 1: microscopic they can potentially be you for things like you know,
Speaker 1: rollable or flexible displays in the future, all right, or
Speaker 1: like a like a blanket TV, yeah, or TV you
Speaker 1: could like fold up and you know, stick in your
Speaker 1: pocket or something. Alright. What else can we use quantum
Speaker 1: dots for? Another awesome application is in solar cells, because
Speaker 1: again you can really tune the absorption and the emission
Speaker 1: then you can get quantum dots that absorb light at
Speaker 1: exactly the peak wavelength that you're seeing on your roof,
Speaker 1: you know, so you can make sure that like the
Speaker 1: peak efficiency for absorption is where most of the light
Speaker 1: actually is, right because right now it's kind of fuzzy, right, Yeah, exactly,
Speaker 1: it's kind of fuzzy. And these solar cells are expensive
Speaker 1: to produce. But if you could get quantum dots ramped
Speaker 1: up so you can make a lot of them, you
Speaker 1: can make basically like solar power paint, and you could
Speaker 1: like have a solution with quantum dots in it that
Speaker 1: you basically paint onto a surface and it becomes a
Speaker 1: solar power cell. What Like, you can just paint your
Speaker 1: roof and then attach some wires to it and it's
Speaker 1: a solar panel. Yes exactly, that is wild. Yeah, they
Speaker 1: would absorb the energy and they would like chain themselves
Speaker 1: up so they can pass a current along and so
Speaker 1: that would be pretty awesome. Like, you know how cool
Speaker 1: it is that you can paint like a chalkboard on
Speaker 1: a wall and it actually kind of works. That's pretty cool. Well,
Speaker 1: this is like a step beyond that. It's like painting
Speaker 1: an electrical device onto your roof or anything, really your
Speaker 1: car or your hat or really you're you can get
Speaker 1: a tattoo. Can you get a solar cell tattoo, you know,
Speaker 1: inked on your skin? It would be awesome, and you
Speaker 1: can charge your phone just by against your body. Yeah,
Speaker 1: and the tattoo should look like a solar cell, and right,
Speaker 1: that would be super cool. It looks like a solar
Speaker 1: cell and acts like a solar cell. Well, technically you
Speaker 1: could make it look like anything. Yeah, you could. You
Speaker 1: can make it look like a rose or your grandma,
Speaker 1: and it would be helping you save some energy, would
Speaker 1: be cool? It power your phone? Yeah cool? All right,
Speaker 1: so you can make solar paint. What else can you
Speaker 1: do with it? You can also use it in science.
Speaker 1: A lot of biology uses something called bio labeling, where
Speaker 1: you like inject some substance into a bacterium or into
Speaker 1: a larger animal, and you want to follow, like where
Speaker 1: did it go? Where is it being used? Where is
Speaker 1: the active site where it's like being actually processed. So
Speaker 1: these quantum dots are like more stable and brighter than
Speaker 1: most of the other dies, and so they're much more useful.
Speaker 1: They can like last for months, but they're also toxicing,
Speaker 1: aren't they. Yes, they're poisonous. I guess if you don't
Speaker 1: want your sample to live very long. Yeah, a lot
Speaker 1: of them. Because you want to engineer particular optical properties
Speaker 1: require you to use various substances like cadmium, which is
Speaker 1: pretty toxic. So we're not at a point where you
Speaker 1: want to You know, your kids eating a spoonful of
Speaker 1: quantum dots are definitely not. But you know, if you
Speaker 1: don't mind killing your bacteria to learn about how it's
Speaker 1: doing something or how it's defending itself, then it's all right.
Speaker 1: Does that put a kaboche on the tattoos as well?
Speaker 1: If you tattoos cadmium into your body, that would give
Speaker 1: you other kinds of cancer. Yes, not recommended. Yet, people
Speaker 1: are working on ways to make quantum dots that don't
Speaker 1: require a cadmium or other toxic materials, so I'm pretty
Speaker 1: sure that in the future will have humans safe quantum dots. Alright, cool,
Speaker 1: What else can we make with quantum dots? Well, we
Speaker 1: can also build super tiny electronics. You know about this
Speaker 1: material called graphine, which is basically like a lattice of
Speaker 1: carbon built in a super fancy interesting way that has
Speaker 1: fancy molecular properties. Well, graphing is really stable and really
Speaker 1: conductive even when it's cut into super tiny devices like
Speaker 1: one nanometer wide. And so you can build like the
Speaker 1: tiniest of electronics using graphing single crystals, which are technically
Speaker 1: also quantum dots that you can make a circuit that's
Speaker 1: literally like one atom talks to another atom, and then
Speaker 1: that atom talks to another atom. Yeah, exactly, And so
Speaker 1: this is like one potential way to even further miniaturize
Speaker 1: our electronics. But wouldn't it get quantum at that point
Speaker 1: or like, would it still behave like a regular circuit.
Speaker 1: It would get want them exactly, but so you have
Speaker 1: to define it to do exactly what you want. But
Speaker 1: you can build transistors out of single atoms, and single
Speaker 1: electron transistors are a thing you can do. The chemistry
Speaker 1: and the physics is a little bit different from the
Speaker 1: way we're currently doing electronics, but you can build the
Speaker 1: basic components we need for circuits out of these graphing
Speaker 1: single crystals. All right, Well, but it sounds like maybe
Speaker 1: the technology that's pushing it at least into the mainstream
Speaker 1: is this idea of a quantum TV. So how far
Speaker 1: away are we from that? Are they actually starting to
Speaker 1: make them or think about them or Netflix investing on this. Yeah,
Speaker 1: quantum TVs are negative five years away, which means they've
Speaker 1: been on the market since about What what do you mean,
Speaker 1: like you can put in money to buy a quantum
Speaker 1: TV ten years in the future. No, that means five
Speaker 1: years ago, if you went on Amazon and typed in
Speaker 1: quantum l e ED there were TVs for sale that
Speaker 1: you could purchase. You could go purchase a quantum l
Speaker 1: a ED TV right now. But it's not really made
Speaker 1: out of quantum dots, is it. No, it really has
Speaker 1: quantum dot technology. Oh, this is really a thing. Really wow, Okay,
Speaker 1: it's not a future technology. It's like five years ago technology.
Speaker 1: It's like Obama years technology. Exactly. Obama probably has a
Speaker 1: quantum TV and he's probably sitting in front of it
Speaker 1: eating quantum cookies right now, because yes, we can watch
Speaker 1: a quantum TV. Really, So if I buy a quantum TV,
Speaker 1: it has like quantum dots in it, Yeah, exactly, it
Speaker 1: has a quantum dot layer which filters this like led
Speaker 1: backlight and helps reduce better color. So, like we were
Speaker 1: saying at the top of the program. Quantum TVs are
Speaker 1: not a scam. They are real and they actually use
Speaker 1: quantum technology. Unlike quantum yogurt and quantum hamsters and quantum
Speaker 1: massage and quantum stealth technology. This is real applications of
Speaker 1: quantum mechanics on your wall right right. Although you know,
Speaker 1: technically yogurt does have quantum particles in it. Everything tastes
Speaker 1: like particles. In the end, it's just a good figure
Speaker 1: and gut. All right. So have you seen a quantum TV?
Speaker 1: Does it look crisper and does it look nicer? I
Speaker 1: think you should do some research and you'll maybe buy
Speaker 1: yourself a TV with your grant money. Yeah, maybe I will.
Speaker 1: You know, I did look up quantum TVs, but I
Speaker 1: can only watch a video of a quantum TV on
Speaker 1: my non quantum screen, and so it doesn't really come through.
Speaker 1: It's like looking at a video of a high definition
Speaker 1: television on your low definition television. It's not very impressive.
Speaker 1: So I've never actually seen one. And also the only
Speaker 1: clip you can watch is a clip of vaculating quantum leap,
Speaker 1: which doesn't help you. Yeah, they need to work on
Speaker 1: the quantum content, really, but no, I've never actually seen
Speaker 1: one in the wild. So any listeners out there that
Speaker 1: have a quantum screen right to us and let us
Speaker 1: know how awesome is it. Yeah, take a picture and
Speaker 1: send it to us to see how good it looks.
Speaker 1: Take a quantum picture. Yeah, we'll get it and not
Speaker 1: get it at the same time. All right, Well, um,
Speaker 1: that's pretty cool that this technology is out there. It
Speaker 1: is being used on televisions. People are technically potentially watching
Speaker 1: Netflix right now with the quantum TV, I hope. So
Speaker 1: all right, and it might potentially give some pretty amazing
Speaker 1: technologies in the future. That's right. With the power to
Speaker 1: understand the quantum world comes the ability to engineer it
Speaker 1: and have it do all sorts of things that normal
Speaker 1: atoms cannot do. So it's not just that physics is
Speaker 1: playing with the universe because we want to understand, but
Speaker 1: sometimes there are actual benefits for humanity. Yeah, yeah, stay
Speaker 1: tuned for those quantum tattoos. Will every physicist get one?
Speaker 1: Just do like, you know, show solidarity and team spirit.
Speaker 1: I don't think you could ever say every physicist will
Speaker 1: do anything apply for grants. All right, Well, we hope
Speaker 1: you enjoyed that, and we hope you look at the
Speaker 1: world a little bit different. Sometimes, quantum technology and quantum
Speaker 1: effects are there for us to see and for us
Speaker 1: to bench watch with. Well, thanks for joining us, See
Speaker 1: you next time. Thanks for listening, and remember that Daniel
Speaker 1: and Jorge Explain the Universe is a production of I
Speaker 1: Heart Radio. For more podcast for my Heart Radio, visit
Speaker 1: the I Heart Radio Apple Apple Podcasts, or wherever you
Speaker 1: listen to your favorite shows. Ye