Our new episode is available from our Podcast host here: Episode 50

We’re also listed on:

• Apple Podcasts
• Stitcher
• Google Podcasts

---

Further Reading:

• Lyra’s twitter and research lab
• “What Is Quantum Physics?” (Caltech Science Exchange)
• “Explainer: What is a quantum computer?” (MIT Technology Review)
• Vacancy centers
  • “The Nitrogen-Vacancy Center in Diamond” (Awshalom Group, University of Chicago)
  • “Nitrogen-Vacancy Spin Defects in Diamond” (Yao Group, Berkeley)

---

Transcript

(this transcript was auto generated and has not yet been edited for clarity and accuracy)

Charles 0:23
Hello and welcome to assigned scientist at bachelors. I’m Charles and I’m an entomologist.

Tessa 0:28
I’m Tessa and I’m an astrobiologist.

Charles 0:30
And today’s our guests we have Lera Lyra she they is a PhD student in Sydney, Australia and is researching emerging quantum technologies. Quantum physics describes the smallest and most delicate systems in the universe. And as our understanding grows, we can use these same systems to create new technologies that push the boundaries of sensitivity and accuracy to their limits. Lyra is also passionate about science, communication and diversity and wants to see quantum be more wondrous and welcoming than intimidating. Lyra. Welcome to the show.

Lyra 0:57
Right. Thank you so much for having me.

Charles 0:59
Thank you for coming on. So generally, to begin with, we like to ask our guests, how did you get started in science? How did you get interested in science,

Lyra 1:06
I’ve always been fascinated by how things work. I think as a child, I would spend a lot of time whenever there was like stuff to pull apart or figure out how it worked. I love kind of just getting in there and trying to figure it out and playing with the electronics and stuff. And I think that kind of impulse was there from the very beginning. But I’ve always wanted to go into some kind of feels like that. But when I first started off at university, I was about 5050, whether I was going to go into linguistics, or physics, and it just kind of physics ended up winning out a little bit. And then the more I did, the more I fell in love with it. And I wanted to go into research, because I don’t know, I guess an altruistic sense of wanting to try and make the world a better place. And even if it’s just contributing a tiny bit of knowledge to one specific field, but it increases what we know about the universe. And that makes us better.

Charles 1:57
That seems like a great motivation to me in physics itself. So you study quantum physics, how did you go towards that path?

Lyra 2:05
I think it’s always been the most kind of engaging to me, I think my interest in wanting to know about how the world around me Works has always been kind of focused on kind of like going inwards more as opposed to kind of like walking out towards the universe, I see something. And I want to know, internally what’s making this work and kind of dive down into it that way. So it was kind of I was going through physics undergrad, and learning about atomic physics and this kind of thing, it just kind of, I kind of naturally started doing more of the quantum kind of atomic kind of units and less of the Astronomy and Astrophysics units. And I think just people talk about quantum physics being a very beautiful theoretical framework to describe the world in, which is true, but I’ve never been fantastic at Maths. But there always has been a certain appeal about how the way that quantum physics works. It’s such as relatively simple framework that describes so many different systems. And this is kind of why quantum computing is such a big thing is because you can have all different kinds of systems that work in completely different ways. But because they have exactly the same maths, which underlies their structure, you can use them for the same thing. And that kind of universality and how it underpins everything we see around us in every direction, I think that’s always been something very compelling to try and understand how, in the very smallest ways how everything around us is put together.

Charles 3:30
I think quantum physics is probably one of those disciplines that people have an idea of what it is, but maybe you don’t know precisely sort of the disciplinary parameters of it. So could you give sort of just an a total beginner’s guide to what is quantum physics actually,

Lyra 3:49
so quantum physics is about, like, I kind of said in the bio, in the beginning was about the smallest and most sensitive systems in the world. But it’s really the theories that describe everything when they are very isolated, and well insulated from the outside world. So if you can get a single atom and not have it interacting with anything, and it’s in a vacuum, then quantum physics is the theory which describes how that works. If you have something which is really close to absolute zero, then it’s got very little thermal energy, and then quantum physics, you would use that to describe that as well, because it’s, it’s all about things when very cold or when they’re very sensitive or when it’s individual things by themselves. And it’s when we start kind of adding lots of these together, and they get like noisy and warm and hot that kind of more classical physics kind of takes over. But it’s about single atoms or things that are really close to absolute zero, and lots of different things in different areas of physics, but that those kinds of situations are when you would see quantum physics coming up.

Charles 4:54
Not to be too harsh right out the gate. But just the way your child Talking about it really does remind me of the way that biologists sometimes like to dunk on physicists, of sort of my discipline can actually describe real material phenomena in the world that yours is only dealing with theoretically, like, no kind of just playground to using just yeah, I,

Lyra 5:28
it’s very easy to see how it kind of looks that way from the outside, especially when you try and talk about it in broad strokes like this, I guess it’s probably a lot better to give kind of like examples. So you can see the ways that this kind of is applicable for a lot of things. So one of the big places that everyone kind of knows that uses quantum physics is the gravitational wave detector LIGO, they use a lot of knowledge about quantum physics and how we can manipulate that to be able to have the sensitivity of LIGO be enough to actually detect the things that we’ve been detecting, without understanding how the quantum theory of light works, we wouldn’t be able to detect the gravitational waves that we’ve been detecting the other kinds of things. So my research, in particular, it’s to do with diamond. And you can have kind of defect centers in diamond. So you just have something in the diamond, which isn’t carbon. And then because that’s kind of really well insulated by being in the middle of a diamond, like nothing can touch it really, then that has really nice kind of electronic properties. So we use our quantum physics to describe the way that these defect centers and diamond work. And that allows us to build stuff like high accuracy clocks and magnetic field sensors, and do a lot of things like that. Well, as

Charles 6:41
you introduced, could we actually get more specifically into what your research is what you’re working on?

Lyra 6:47
Yeah, absolutely. Yeah. So like, I was just kind of saying it’s to do with defect centers in diamond and the particular ones that I work with a call nitrogen vacancy centers. So in like, diamond is a crystal lattice in that, like, there’s just a periodic pattern in which the carbon atoms are bound together. But if you replace one of those carbon atoms with a nitrogen atom, and then you get rid of one of the atoms, so there’s just like a hole where there should be an atom, but there isn’t, then that has this really nice electronic structure, which kind of mimics the behavior of a single atom in that it’s got kind of different, well defined energy levels. And then there’s mechanisms that we can use to manipulate the electronic structure. Is this making much sense, though? Like, I think,

Charles 7:35
let me try to rephrase. So basically, diamonds are well known as being a girl’s best friend, first of all. Secondly, they their value, the value that we’ve attached to them both Well, the the functional value that they have is really in how they are a very rigid, hard crystal and structure, like it’s very well ordered. There’s kind of no chaos happening there. Yeah. Although I realized chaos has probably a very particular meaning and physics, outside of vernacular colloquial use, but let’s go with it. And so if there are these different elements, for example, nitrogen that gets into that structure, is it that how well structured how rigidly structured the diamond is? It kind of creates this kind of environmental insulation around that other element?

Lyra 8:29
Yeah, exactly. But that’s exactly what’s happening. Yeah, didn’t take that

Charles 8:34
my my regular underperformance in physics in high school.

Lyra 8:40
Yeah, so it basically means it’s like an atom, but we can pick up that atom and move it around. And like we can hold it in our hands, and it’s not going to interact with the atom.

Charles 8:50
So, so it is kind of like taking the sort of vacuum of real space. That is the theoretical basis of a lot of problems in physics, and then finding an actual, like, real life example of we did it. We found it.

Lyra 9:07
Yeah, so yeah, you in an ideal situation, if you want to describe how anatomy, once it’s, well, it’s in a vacuum, there’s nothing else around it’s zero temperature, and there’s no light shining on it. And like you’re never gonna see that in real life. But by having this very ordered, symmetric structure around it, you can have pretty much the same thing. If you design it, right. Yeah, I have

Charles 9:29
what may be and we’ll see how this question goes. But basically, it the way that we the biologists love to dunk on physics is, you know, this very, so much of people say how it behaves in a vacuum. And then it turns out, you can’t actually observe things in a vacuum. So how to how to physicists make Basically, how would you know how something would act in an environment that you can never observe? And also could not physically exist? Does that make sense? Yeah,

Lyra 10:12
that makes sense. It works because of the theories that we use to describe it. And then that allows us to make predictions about how the system would work in less than ideal circumstances. So a lot of the theories start from a point of view, it’s in a vacuum, and there’s nothing touching it or interacting with it. And no, we can never do that. But if we add one more layer on to our theory of saying, Well, this system, how would it interact with this particular framework of things, and then we designed that little bit of extra theory that we’re adding on to it to reflect a real world scenario in which we could actually interact with this thing. And then we are able to make observations with that and experimentally explore what happens with that system in this particular framework. And then the way that these theories in physics kind of work, if the underlying theory doesn’t work, or doesn’t work in a particular way, then we’re not going to have results that agree with our more complicated theory. So even if we can’t directly say that, we have observed this particular thing, by adding a bit more to our theory and applying it in a particular context, we can make observations and that means that the whole thing is sound. And it’s not that simple, because you have to be very careful about how you construct the theories to make sure that like you are not accidentally coming up with something which makes it look like it’s working. But it’s actually not. But it’s kind of through systems like that we can infer something about the underlying theory by applying it to a situation where we can actually look at everything properly.

Charles 11:51
I, I’m always odd, when I read back into history of science, the things that I know about, like foundational experimental studies in well post Newtonian physics, like the, you know, the determination of what electrons are, I’m always amazed that people were able to get to that point, because the other thing about physics, that always throws me for a loop, particularly as you know, an entomologist, as a biologist, I can hold an insect in my hand and go, look at that. You you can’t hold an electron. Or rather, you’re constantly holding many electrons. But it’s not like you can yet it’s not an insect is what I’m saying.

Lyra 12:42
No, it’s not. But this is something that kind of like you start exploring, if you do kind of like undergraduate physics, and maybe in your like, second and third year, you can’t pick up and hold an electron or directly see a photon. But you can do things with them, which makes their presence incredibly obvious. And so like, even in first year physics, you will do kind of like interference experiments where you kind of interfere light with itself. And then you have this pattern showing up. And it’s like that could only happen if light is acting as a wave. And you can see it right there, you can see very clearly this interference pattern showing up on this screen. And it’s just in a first year laboratory. And stuff like electrons as well, we can’t ever pick one up and see it directly. But we can design a detector, which only kind of detects when an electron hits it. And then we can have like an electron gun, and we can point it at the detector. And then suddenly, we’re seeing all these like little spikes of detection coming up on our screen. And so it’s like, we know that electrons are there, because we’ve designed this thing. And we know very well that it will only interact with electrons. And we can see interference patterns with electrons as well. Physics is very different from a lot of other sciences. It’s it’s all about inference and being able to draw conclusions from well, we’re seeing this and that means these things about the underlying way that it’s working.

Charles 14:08
So would it perhaps be accurate to say that initially, the electron was kind of a theoretical construct, there’s the observation of a phenomenon. And then there is the theoretical presentation of a concept that might describe that phenomenon, and then experimentation to specifically isolate and identify what that influencing object is. Does that make sense? Yeah, no,

Lyra 14:40
that’s exactly how it goes. It’s kind of it’s the same process that we have with like the Higgs boson and stuff. We have this theory about how this thing works, but we’re not really sure exactly what’s going on or what particles are involved. And then someone proposes a theory and they’re like, Well, maybe it’s this Higgs Boson thing that is doing this and then we don’t really know. And then we come up with some experiment, which is designed to test that particular theory of the Higgs boson. And then we find out that it’s real. And like exactly the same thing happened with electrons, we could see that if we connect it up some particular chemicals and stack them together, then you would have some kind of something flowing through these metal cables. That is making something shine or heat up or move. And we don’t really have any idea what’s going on. And when like the theory of kind of like electrons and electricity was being created, there were countless different people who were probably working on this and trying to come up with a theoretical framework that properly described what we’re seeing. And then we only know about the one that says says, succeeded, because it was the one that succeeded. But every time in physics, that’s the way that it works. It’s there’s a phenomenon. And we want to describe how it works. And we go around searching for a theoretical framework, and we test all of those. And then eventually, hopefully, we find the one that works. I think

Charles 16:04
maybe an example from biology that might make sense to people is that when Darwin was working, for instance, when there was a lot of this conversation about what was driving evolutionary change, there was the acknowledgement that there was something in organisms that led to the inheritance of traits, but they didn’t know what that thing was. So it was the sort of the idea of the unit of inheritance, like the thing that cause inheritance of traits was purely theoretical, until we got into the 20th century, and we identified genes and DNA, and then we were able to attach the, you know, the physical thing that caused inheritance backwards to our understanding that inheritance was happening. Do you think that’s a good comparison?

Lyra 16:56
Yeah, I think it is that fits nicely. Yeah.

Charles 16:59
I’m batting 1000 today. So going back to your own specific research working on these diamonds, like what is this connecting to, in general to ongoing problems in physics?

Lyra 17:13
So the area of physics I’m in, it’s not necessarily pure research, it’s. So a lot of the fundamental stuff about quantum physics is kind of like settled. Now, we have our theories, which describe most of the stuff we see around us. And there’s obviously areas that need work done on them. But a lot of it now is, I mean, everyone knows about the enormous amount of buzz around quantum computing. And that kind of thing. Well, actually,

Tessa 17:40
yeah, people may have heard of that term, but they may not really understand what

Lyra 17:43
it is. Yeah, that is something I kind of wanted to try and talk about a bit as well, because it is the thing that gets the most buzz and the most hype, and it’s the kind of thing, everyone only ever hears about this and doesn’t hear about anything else. Quantum Computing is one example of a quantum technology where we’re now using our understanding of quantum physics to build new technologies. And so my particular research using these diamonds and these nitrogen vacancy centers, what we’re doing with this is we’re using it to build high accuracy clocks. So the kinds of clocks that would be used in GPS satellites, where you have to worry about relativistic effects. At the moment, the kinds of clocks that they use are like incredibly big and bulky and expensive. But these systems that we can make with these nitrogen vacancy centers, potentially can be just as accurate. But at an order of mag orders of magnitude cheaper and smaller, which would potentially allow us to have kind of like GPS, accurate clocks on small satellites, or cube sats and that kind of thing.

Tessa 18:46
I just want to point out to our audience, that the reason GPS satellites need those very accurate clocks is that due to general relativity, they runs at a slightly different speed than clocks on Earth. And after a while, that starts to cause your locating system if it’s not accounted for to become inaccurate. GPS needs clocks better to the sector, because otherwise it literally will not work.

Lyra 19:09
Yeah. If you had like your regular digital watch clock on there, very quickly, your position on Google Maps would start drifting away from where it actually is. We’re in this stage now with quantum physics, where we’re starting to develop quantum technologies, so technologies that we could only design because we know how they work. And so that’s kind of where a lot of research efforts are focused at the moment, it’s finding new ways to solve problems using quantum systems as opposed to classical physical systems. How does what you’re working on fit into that? It’s a little bit complicated to explain. But essentially, we can have a diamond which has lots and lots and lots of nitrogen vacancy centers in it and the way they work I kind of said before that they’re kind of like an atom that you can kind of pick up and move around which has nice energy left. All right. So we kind of know that atoms have electrons around them. And that those electrons can go to different, like excited states or their ground state. And they have different energy levels. And that when they move between those, they either like absorb a photon or emit a photon,

Charles 20:18
what could we take a moment to insert a very brief sort of reminder of what excited ground photon mean, for people who don’t, who maybe don’t know.

Lyra 20:29
So photons are little packets of electromagnetic energy. And electromagnetic energy can be created by moving around something with an electric charge. So if you shake an electron, which is negatively charged, then you’re kind of sending ripples out in this kind of like electromagnetic field. Whenever you move something which has a charge, ripples of electromagnetic energy go out. And so this happens on very big scales. And it happens on really small scales as well. So when you have an electron going around an atom, and it moves up, then it has to be interacting with the electromagnetic field to be able to move, or if it moves, then the electromagnetic field has to change in response to it. And then it has to send out those ripples. And so the excited states and the ground state, just describing how close the electron can get to the atom, like positive and negative charges are attracted to one another, and the nucleus of an atom is positively charged and the electron is negatively charged, then the electron wants to be as close to the atom as possible. And that’s its ground state, it’s kind of like attracted there, it’s like two magnets pulling together. But if you put some electromagnetic energy into the electron, then suddenly it has a bit of energy to get further away. And so it can jump up to one of the excited states because it’s absorbed a little bit of energy. And now it can push away more. And then the same kind of thing. If it gets Oh, well, now I don’t have enough energy, I’m going to like, magnetically attract back to the ground state, then it’s going to remit that energy as a photon. And yes, so we’ve got a whole bunch of these, which basically act like that they’ve got excited states and ground states. And anything which is in an excited state is at some point going to want to decay back to its ground state, what we can do is buy one of the energy levels, the kinds of photons that it emits when it decays back to its ground state, microwave photons, what we do is we basically, by manipulating the NV centers with kind of like magnetic fields and lasers to illuminate it and kind of manipulate it or when a particular way, we can basically make it so that it’s emitting microwave photons, and building up like a population of microwave photons in something we call like a resonator. And this would be kind of like, if you imagine you have two mirrors facing one another, and then you’re just going to have light bouncing back and forth in between those two mirrors, and it’s going to like grow up in intensity. If you’ve got like a razor with like two mirrors on either side. Well, and

Charles 23:09
to be clear microwave here, microwave here refers to like the range of like wavelength.

Lyra 23:16
Yeah, exactly. So microwave radiation has wavelengths of like a, I don’t know, between millimeters and centimeters. So for example, visible light is kind of like hundreds of nanometers. And like one nanometer is kind of like, the, the way I always come back to explaining it is one nanometer is how far your fingernails grow in one second. So every second, your fingernails will grow by one nanometer. And so that’s kind of that’s the timeliness of the length scale that we’re looking at.

Charles 23:50
How well how did a physicist figure that out? Just for fun, or how did we get to that statistic.

Lyra 23:59
So it’s just kind of like a pretty basic kind of measurement thing. Like if you just, I don’t know, if you want to take a week and say, Well, this is how far they grew in a week, they’ve probably grown enough that you can measure that fairly easily. And so you’ll just kind of say, well, how many seconds are there in a week. And then I’m just going to divide the amount that it grew in a week by how many seconds there are in a week, and that’s kind of how long it grows each second.

Charles 24:24
And people think that funding for science is most appropriate. It isn’t just let’s all be serious for a second give more money to scientists.

Lyra 24:35
Yeah. So basically, these kinds of lasers been made with microwave photons. That’s what’s used for these GPS satellites for their clocks, something called a maser, which is kind of like a microwave laser. And we’ve kind of had these things called hydrogen mazes for like 4050 years now. And that’s what’s used in all these GPS satellites, but they’re really big. And they’re really bulky and expensive. And so we can make something like that. But it’s solid state, it’s a lot less quick, it’s a lot more robust mechanically, because it’s just made out of diamond. And so the hope is that we can build mazes, and have that be a kind of like new technology, which is available, which is also going to be it’s incredibly accurate the same way that like the stuff in GPS satellites is, but it’s going to be accessible to a lot more people. And so you can use it as quarks. But because it relies on magnetic fields, that means that if your magnetic field changes, then the power coming out of your major changes. So you can use it to detect changes in magnetic fields. And so that’s what we’re really doing. Were trying to develop this technology and kind of develop the sophistication and our understanding of it to the point that we’ll be able to make things with this that we can then like, we’ll be able to improve the kinds of things that people can build.

Tessa 25:59
So hypothetically, what would be the optimal result or the result you’d be most excited to see come out of your research.

Lyra 26:06
Yeah. So I think really, the thing we would love to be able to get to is having one of these major systems built on like a microchip. And at the moment, that’s kind of like a little bit far fetched because of the components of the system have to be designed in a very particular way. And a lot of them can’t be made really, really small. They can be made a lot smaller than what’s there at the moment. But none of them are really the kinds of things that you can just put on a chip and be done with it. But there’s not necessarily anything theoretically standing in the way of making these things so that they can be put on just like a little microchip and be on a circuit board inside something larger. What we would love to see at the end of all of this is being able to design an on chip, high accuracy maze, which we can use as a high accuracy clock, which would match the standards of things found in GPS satellites, because if we could do that, it would be something that can be mass manufactured incredibly cheaply, it would open the doors for a whole lot of stuff for a whole lot of different industries. Because these high accuracy clocks, they’re not just useful for GPS satellites, they’re useful for a lot of other lab work in physics, having a really accurate clock that you can measure time with helps you explore a lot of different things in a lot of different ways. So speaking

Charles 27:22
about manufacturing objects are the diamonds you’re using naturally occurring are these manufactured diamonds.

Lyra 27:30
Ah, so the ones we’re using at the moment are manufactured. But you can also get natural diamonds with nitrogen vacancy centers in them. These kind of like defect centers, you can have all different kinds of things, you can have different atoms replacing the carbon atoms in the diamond defect centers are what make different colored diamonds have that particular color. So like nitrogen vacancy centers, if you have the right concentration, they make a pink diamond. But if you have too many, then it turns kind of like a Blackie red color. And you can have different defect centers, which makes them like green, for instance, when research was first being done with nitrogen vacancy centers, it was being done all with natural diamonds, because it’s only in the last decade or two that we’ve really been able to start manufacturing them properly. And so that’s one of the things which is allowing this kind of research to take place is there is there is a ready supply of lab grade diamonds where we very, very, we understand very well the properties of these diamonds because we’ve been able to manufacture them from the raw atoms and we know exactly what’s in them. We know the concentrations. And we know how it all works.

Charles 28:36
Why nitrogen specifically, could you give like specific examples of like, what are the properties of nitrogen that make it a good choice for what you’re doing with it?

Lyra 28:47
Yeah, so it’s, it’s mainly to do with the amount of electrons which are free for being able to bond and so we know that like a lot of chemical bonds come from just electrons being shared between two atoms, and then that ties those atoms together. And there are some number of electrons which are available to bond with other atoms. The reason that diamond is such a strong hard material is because once those bonds have been formed, there are no electrons leftover. And there’s no places where it’s possible for extra electrons to be to increase the strength of those bonds. And so that’s kind of like the the electrons which are available to form chemical bonds are called the valence electrons. Why we like nitrogen so much is basically that it has the right amount of valence electrons that gives a particular electronic structure to the nitrogen vacancy center that we want. So the properties of the nitrogen vacancy center which are really important is the fact that it’s got an excited state and the ground state, but within the ground state, there’s kind of like Something which we call the fine structure, which is really, really tiny energy levels within the ground state and within the excited state. And so it’s that structure, which is allowed by the number of electrons that the nitrogen has started because it has like five valence electrons, a couple of those get used up bonding to the carbon atoms, and then a couple of those are left hanging around in the hole where there should be the vacancy of the nitrogen vacancy. And so the number of electrons that are leftover after it’s bonded to the carbon means that it has this ground state and this excited state, but it also has this ground and excited state within each of those this fine structure. And it’s that fine structure, which is actually what has the microwave radiation associated with it, we like we have to have two free electrons, and they have to be in a particular configuration in a particular place. And the nitrogen is the atom on the periodic table, which has the right amount of valence electrons that lets us do that. But them

Charles 31:14
Do you have anything else that you would like to specifically talk about,

Lyra 31:19
I did kind of want to talk a bit about kind of like quantum computing, because that is the kind of thing that people know most about, or like have heard most about and know nothing about really enact, like in reality, and it’s, I guess, like a kind of like a thing that I keep finding myself coming back to is feeling upset at the reputation that quantum in particular has, and how intimidated people feel by it. And the kind of the way that certain shitty guys within the field like that reputation, because it makes them feel important and superior to other people, which just grinds my gears horribly. To give people a bit of a better understanding about like kind of what quantum computing is, and why it’s so exciting. The best way to kind of like convey to people the kind of the changes between this and regular computing is if you think about a normal computer, you have a certain amount of bits associated with it’s like everything is just zeros or ones. And we talk about how many parameters do we need to describe the state of a regular computer? Well, you just name however many zeros and ones the computer is using to do its stuff. If the computer has this many bits, then you just need that many numbers, you just need that many zeros or ones to describe it. But the way quantum physics works is very different from that. Whenever you have two quantum systems interacting with each other, the number of parameters that you need to describe them grow, not grow exponentially. So if you have an atom, and it has a ground state and an excited state, then you only need kind of like two things to describe it, it’s just a zero or one. But if you add another like atom to that, and now you’ve got two things which can either be zero or one, you don’t just need two parameters to describe that because they can become entangled. And entanglement is one of the kind of like big things in quantum physics. But what this means is that, for two atoms that are interacting, you now need four parameters to describe their state. And if you have three, then you multiply that by two again, so you’ve got eight parameters that you need to describe it. And so that pattern kind of grows, it’s like two to the power of however many atoms you have. And so when you get up to like seven, eight, even just like 10 atoms that might be interacting with one another, then suddenly you have like hundreds and 1000s of parameters that you need to describe these systems. And quantum computing has the potential to be so powerful, because we can do calculations in the size of that parameter space. So like, we have like 1015, like things which are interacting with one another. But then the mathematics that we need to describe that has like hundreds of different things that we can play with. And we can manipulate all of those and do calculations using all of those. And so the kind of the the best kind of example that I always come back to is people talk a lot about how quantum computers can break encryption that we rely on. And so a lot of encryption standards basically rely on we’ve got some function which is so complicated that we can never figure out what the input was based on a given output. And so we just have to guess and this is the only way of breaking encryption is you just have to guess over and over and over again until you eventually get the right answer. And that’s just, it takes a lot of time to do that. But quantum computers, you can basically calculate the output of all possible numbers at once, and then just pick out the right one at the end. Because that’s the size of that space is so big, we can just create this state, which is kind of like an entangled state of all possible numbers at the same time, and then just do the calculation once. So like, it’s, that’s kind of like on a very kind of like bare bones level, what kind of like the potential power of quantum computing is, it’s just that we’ve got this mathematical space to play with that grows so so so quickly. And that gives us a lot of power and a lot of freedom to be able to do different things that weren’t possible before.

Charles 35:53
Thinking about that, going from a description of what is just speculation of what may be, how do you imagine this might be used in the future, and you can be as grounded or as bonkers off the wall speculatively, speculative as you would like,

Lyra 36:17
it’s easy to get carried away with imagining how things might be. It’s, especially when there’s such like recent comparisons with like classical computing, and where we were like, I don’t know, in the 40s, and 50s. And the very first computers, you think of them, like being done with like punch cards, and entire buildings filled with just reels of tape, or whatever other kind of computing thing you’re doing. And it’s kind of like, that’s where we are with quantum computing. At the moment, it’s kind of like, we’ve got these very, very rudimentary machines, which can do some stuff, but they’re, they’re so far away from being able to do anything useful. The same, the same way computers back then was so far away from being useful. And so at the moment, we still don’t even really have like a settled idea about what the best way to build a quantum computer is. With classical computers, it took a while to figure out what’s the best way to build memory? Is it kind of like magnetic tape? Or is it kind of, like an actual magnet is like, the magnetization of like, a particular thing that there were all these questions that we have to solve. And that’s where we are at the moment, it would be nice to think that someday in the future, we’re gonna have be able to build quantum computers, which don’t rely on having like a ready supply of liquid nitrogen and liquid helium to cool everything down, and that we might be able to miniaturize this a bit. And we’ll be able to solve the problems of how it scales. And then with that, kind of, you can kind of imagine that, we will be able to have some kind of common usage that exploits the powers of quantum computing to do things the way that computers do for us today. And that might happen, but it might not happen. And it might remain the kind of thing that universities will use quantum computers in places like Google might have them to be able to do particular kinds of research. And that’s kind of like a lot more realistic in the near term. But it’s really a bit early to say.

Charles 38:11
Okay, so in an attempt to put it maybe as simply as possible, well, what is computing for

Lyra 38:19
computing is full, on a very basic level, just doing lots of maths very quickly. And by doing lots of math very quickly, we can display stuff, we can render things, we can record things and but on a fundamental level, most of that is just kind of like mathematical operations. And quantum computing is just kind of like increasing the range of different things that on a base level we can do.

Charles 38:43
And it seems like it’s also connected to how much you can do overall, as well as using space more efficiently where like a lot of the advancements in computing that we have, from the early building size computers to today, where I have a phone that has more like computing power in it than a building did 60 years ago. It’s it’s making things on a smaller scale, so that they can both do more overall as well as do more with less.

Lyra 39:21
Yeah, and that’s exactly that’s, that’s behind most of the problems that quantum computing is trying to solve at the moment is to do with the size, but perhaps more than the size. It’s how you scale these systems. So we can build a quantum computer at the moment that is this particular size. But it’s not necessarily an easy way to add more qubits into this system. There comes a point where you’ve got so much control stuff around it that there literally isn’t any more space on your like chip to be able to add any more in and then we don’t know how we connect these two together. So Like even if you had two of those systems sitting next to each other, we don’t necessarily know how we would make them talk to each other so that they can work together on a problem. So yeah, a lot of it is about miniaturization and being able to make these systems smaller, but as well as making them small, the particular problem with quantum computers is, how do we get them to talk to each other in a way that allows them to combine their powers

Charles 40:25
and sort of what is it precisely about quantum physics and quantum computers, that opens up this potential for improving things in this way.

Lyra 40:35
Like I was saying before, it’s really just the size of that mathematical space that you’re using to do your calculations. And the entanglement of these quantum systems allows you to do stuff by making a state, which is all possible combinations of a number at the same time. And that kind of thing is where quantum computers really excel, and also being able to directly simulate like, complicated systems. So at the moment, like we can, we can describe a hydrogen atom really well. But the underlying physics gets really complicated as soon as you start trying to like simulate, like from first principles, any other like atoms in the periodic table. But because of the size of kind of quantum computers and how they work, it’s actually really easy to be able to map the parameters you want to simulate if anything on the periodic table directly on to how a quantum computer works, and be able to directly simulate something like that, and then get perfectly analytical results afterwards, which is not something we have any way of doing at the moment. And so that’s one of the big applications is being able to simulate kind of like chemical reactions from first principles from like the very basic quantum physics rules of how things work, we can potentially simulate, like chemical reactions between different molecules and atoms.

Charles 41:57
We can go to the final section of our podcast where we ask our guests to weigh in on one of our science fictional hypotheticals. I did you send you this list? Is there one, or multiples that you would particularly like to answer?

Lyra 42:12
I mean, it’s hard for me to go past the classic robot body one.

Charles 42:17
It’s, I mean, it is a classic. So if you were about to die, would you put your brain in a robot body?

Lyra 42:24
I think I would, I think I have a couple of reservations about the kind of capabilities of this robot body, like, what kind of robot are we talking about. But I don’t necessarily know that I would even want to wait until I’m dying. If it was the right kind of robot, it just seems like a win win to me. I don’t know, I feel especially he’s kind of like a trans person, there’s a lot of, there’s a lot of potential for exploring the bounds of kind of like what a person can be and what kind of things are fulfilling and meaningful when you have complete control over something like that. And like it’s been a common theme in science fiction is the ways that we can like us kind of like cyborgs or robots and that kind of thing to explore, explore themes of kind of oppression, but also freedom from those kinds of structures, and what that allows people to do, if our world can one day get to the point where robot bodies are an option, I would be very, very happy.

Charles 43:17
I mean, then the inevitable following questions is, what what would be your standard for an acceptable robot body,

Lyra 43:26
I think a lot of it would come down to mimicking some aspects of what it is to live as a person. So having like sufficient kind of like sensory ability, and also just kind of like freedom, which comes with a human body, being able to travel where you want, I think a lot of it has to do with just kind of being allowed bodily autonomy by whatever robot body that you’re inside and being able to interact with the world in a full and complete way.

Charles 43:54
I think you’re actually the first person who has said, not even just on my deathbed, but just just preemptively like proactively, let’s go robot body, which is very interesting. Because I’m with you, I love the idea of being in a robot body. Although when it comes down to it, like, what I actually put myself in a robot body, I’m a very cautious person. And I feel like there are probably a lot of unknowns in that situation that might make me a little bit squeamish about it. At the very least, I would love to have like a robotic exoskeleton with at least one extra arm, because I’m always thinking it would be great to have three arms make things so much easier. It would be really convenient. Would make finding good clothes a bit more difficult. Yes, although as a trans person, I feel like you probably already feel like finding strands to trans finding closes pretty difficult. Yeah,

Lyra 44:54
no, it definitely can be. I feel lucky that I found that there’s one place in Australia where I can reliably get nice quotes. And that is something I’m very happy about consistently.

Charles 45:06
Because the other thing is, depending on how realistic your robot, like, if you’re going like data, realism, probably nudity is a no go if you’re going like, I’m not proud of it, but the first image that comes to my mind is the Will Smith movie iRobot, or their humanoid, right, but they, they will, first of all, they don’t have genitals. And then secondly, they’re sort of abstracted enough that they don’t even look naked. I think in that case, you don’t you don’t even need clothes.

Lyra 45:38
No, you don’t necessarily need clothes. But I think key to that would being able to modify kind of like whatever you’re like, I don’t know, painted different colors, change the design swap on some different parts, aesthetics, you know, yeah, you need to be able to express yourself through your presentation. Like,

Charles 45:53
I think the final sort of common recurring idea with the robot bodies is basically when do you get to die? You know what I mean? Like, would you want to be permanently in your robot body? I’m going forever, because we had one person previously, who was like, I’m gonna get myself into like a horrible long Furby freaks some people out and then say goodbye.

Lyra 46:18
Yeah, I don’t know that that’s always seemed like such a complicated kind of question. And something which is explored really often, whenever you have some kind of like science fiction, where people are allowed the ability to live forever, and the kind of injustices that come with that. And the kind of the way that exacerbates class systems and are we’re always going to have it so the rich people get to live forever, and no one else does. Yeah, I think ideally, there would be some kind of world where if we’ve developed that, we’re not going to have the same problems we have at the moment, and where maybe in more some kind of like Star Trek utopian thing where we don’t have to worry about those kinds of things anymore. I think ultimately, though, my, I wouldn’t want to be forced to be in there forever. I kind of, I don’t know if you guys watch the good place, but spoilers. Of that I, I adore that idea of what a perfect life would be. And the way that it would end is that maybe not forever, but you are afforded the time to explore your relationships and have the time that you need with people and truly find yourself and explore all the things you want to and then when it’s time to move on, then you can move on.

Charles 47:26
I recently reread the two locked tomb books that have already been published and thinking about sort of resurrection and bringing people back from the dead that it’s just been on my mind and thinking about it. I love my cat. And I keep thinking about like, because you might have noticed also on our list of episode Enders is like, would you clone a loved one, right? Yeah. And I think like, would I want to clone Hank? My cat? No, because it wouldn’t be the same cat would I then if he died, resurrect them. And I get back to I feel like ultimately, that would be very selfish. Because, you know, once he’s lived a good long life, I think we all have the right to die. You know, like, at a certain point, it’s not nice to keep on going. It’s like I’m tired. I’d like to just die now, please.

Lyra 48:17
It’s definitely something which would require consent. Yeah.

Charles 48:21
And unfortunately, he’s a cat. And I don’t think understands mortality. I don’t know. Because like, you know, he’s a cat, but probably I don’t think he does.

Lyra 48:31
What a blessed life to not have to contemplate that.

Charles 48:35
I mean, honestly,

Lyra 48:36
there’s a book I read recently called Unity by a really fantastic trans author. polybags. Yeah, yeah, yeah, no, and it’s kind of like, I don’t know, I don’t want to spoil too much about it. But the way it explores living a prolonged life, and it’s not necessarily immortality, though, it’s very close to that in that book. But I feel like so much of the kinds of stories that we see about immortality and how it’s a cost just as much as it is a blessing. So much of it focuses on the kind of the individual experience and watching people you love pass away and things repeating themselves, where it feels like there would be so much more agency to be able to affect meaningful change in the world, if you have had that kind of experience and that knowledge, and it feels like there is so much that could be explored when you think about the kinds of goods someone could do.

Charles 49:35
You’ve, you’ve been a tremendous guests. It’s been great having you on.

Lyra 49:39
Thank you so much for having me.

Charles 49:40
It’s absolutely if people would like to find out more about you or your work. Where should they look,

Lyra 49:46
if you want to find more about my research. There’s the engineered quantum systems website, which is the research center on McArdle, and I have a page on there and there’s some information there about the kinds of work and research that we’re involved with and then also Macquarie University is the university I met and there’s information out there about the kinds of research we do. They’re

Charles 50:06
tremendous. If you want to follow me I am on Twitter at cockroach orals. I am on Twitter at

Tessa 50:13
spacer Mesa SP AC er NSC. I can also be found on my website Tessa fisher.com

Charles 50:19
The show is on Twitter at ASAP pod or at our website where we post show notes and transcripts for every episode ASAP. podcast.com. And if you like the podcast if you think other people might like the podcast, please tell people about it. Word of mouth is the primary way that podcasts grow.

Tessa 50:35
And until next time, keep on science-ing.