 and welcome back to our regular YouTube series out of IBM Research. I am Katja Moskvich, the communications lead of IBM Research Europe. And as usual, I am here with you in Zurich, in our Zurich labs in Switzerland. You know, it's actually quite funny. When I mentioned that I work for IBM, to people often what they think about is computers. And of course, you know, it's true that IBM, this company that is like more than 100 years old now, is a pioneer in computing. Of course, it made computers mainstream, brought them to people's homes. And it's also been leading developments in AI, in artificial intelligence. And lots of you probably have heard of, I don't know, IBM Watson Computer, for example, winning the Jeopardy game in, I think it was 2011, right? But what's also important to remember is that for like three quarters of a century now, IBM has also been doing research, really, really cool research. Of course, in AI, yes, but also quantum computing. You know, this wonderful thing here is a model of a quantum computer. And if some of you haven't yet seen our webinars about quantum computing specifically, I advise that you do search and go back and watch one, for example, from February where we explain what quantum computing actually is. But we are also doing really cool research in security and hybrid cloud. So a lot of quite amazing, amazing breakthroughs come out of our labs. And of course, one may argue that it's just fundamental research, but at the same time, pretty soon, a lot of this will be turned into applications. And this is exactly the case, hopefully, of what we will be talking about today. We'll be talking about light, right? Light is all around us. So, you know, light from the sun, light in our bedroom from electricity, candlelight, I don't know, campfire light, where we grill marshmallows or whatever it is you guys like to grill, starlight from far away stars, much further than our sun. And there is one element that is, you know, common to all these examples, and it's the photon. So this is exactly what our chat is gonna be about. The photon is the quantum of electromagnetic field, the fundamental particle of light. And while today our gadgets run on electricity, the guys you will hear about in just a few seconds here have developed actually a device, an optical device that could make our gadgets run on light instead. So before I introduce our speakers today, as usual, I urge all of you watching us right now to please, please send us your questions through the YouTube chat. We will try to answer as many of them as we can live. And we, thank you. So we also have our experts in the chat who will be answering them behind the scenes here in the chat directly. So joining me today are Darius Urbanus, a physicist here at IBM Research Zurich and also Pavlas Lagoudakis from the University of South Sampton in the UK and Skoltec in Russia. Hi guys. I got you. So first question for you, Darius. So I'll start with the questions, but I hope our audience will pitch in and send their questions as well. Darius, but a question for you. So, you know, as we're gonna be talking about light in your view, what's so special about light? Why would light be better than electricity when it comes to our gadgets? Yeah, so imagine like now gadgets are everywhere. So, and people want faster and better performing gadgets. But if you really look what is present in the moment, like since 15 years ago, the speed of these gadgets is not really improving. So cold that the denot scaling is kind of a, it's coming to an end. I mean, we still have many more transistors down the chills, but the speed is not going anywhere. So that's why people and researchers, like we actually are looking at kind of different ways of doing this kind of switching. So trying to use, for example, light. And why is light so interesting? Well, light is very fast and can be done very power efficiently. So you could imagine speeds maybe that are running like at Therahertz rates. And what we are showing now in our recent paper is that we can really push this work even to a very few photons. So 10 times less power consumption than the current state of current transistors use. And so maybe you could just elaborate a little bit more on this concept of you mentioned that the speed of light is very fast. I mean, that's the fastest you can get, right? So can you just give our audience, I guess an idea of how fast light actually is and why we would use it for gadgets? Yeah, so in the end, like the light is of course traveling at the speed of light. So, I mean, in our fundamental work that we did, we are using the speed. 300,000 meters per second, right? I mean, the actual... Yes, but in the end, the idea is really that we are able to run the idea is to really have them in the long term to have these devices being switched at very fast rates. So like 1,000 times or 100 to like 1,000 times faster than the nowadays transistors. And of course at the very low power budget, that is like the really the goal in this research field. Cool, and where did you get the idea to even start working on this? Yeah, so the idea is actually the history behind this is very interesting. In the lab already in 2014, here in the group, we were able to show the first time that by using specifics materials, we were able to show so-called both Einstein condensates in our devices. And at that time, Pavlos Lagodagis actually connected to us and asking us, well, guys, let's work together and maybe we could like, let's build something cool. And that's what it came all to in 2019 when we had our Nature Photonics paper where we showed all optical logic gates where we like build end gates for the like at that operated room temperature. Back then, of course, we didn't really like to pay too much attention to like the power efficiency, but this is really what we are doing now. This is all this work that we are really trying to look at this efficiency of this device or really push like this to a single photon level. Mm-hmm, cool. Well, so you mentioned Pavlos, why don't we go to Pavlos? And Pavlos, could you maybe explain to us a little bit more, I guess, in depth what this device can do? So Darius already mentioned efficiency and speed and so what else can it do? Why is it so amazing? Yeah, so first of all, let me tell you about the device itself. So this device is, it's a small, relatively small device that acts like an optical cavity. So if I have, for example, an image of a cavity, you have the mirror into which you confine light. So you bring light and you squeeze it in very small volume. And inside this cavity, you also have a material that interacts with light. So you have something that absorbs light and then it light. And when this process happens, practically you mix light with matter and you create a new type of a hybrid particle, which we call polaritons. So it is a new type of particle and you can see this as a droplet of liquid light. So this Bose Einstein compensate that Darius was talking before. It is nothing else than a droplet of this new type of particles that we call polaritons, which have exotic properties. It is actually something like the fifth type of matter, if you like. And this kind of exotic state now, once you can start interacting with it, you can start playing with these exotic properties. And what we did, if we can see, for example, the cavity, a schematic of a cavity, what we do on this device, we sign light, we create this droplet of light and then we can now manipulate it using down to single photons. So you can use this, for example, as a switch. You can use one photon to create this liquid droplet of light, which then results to many photons coming out of the device. So it is like a light amplifier, like you have a sound amplifier, imagine a light amplifier with one photon, you create a lot of photons that carry the same properties. So this is the type of the switch, which then you can use to amplify signals. And of course, there are many, many applications that carry on from the switching and amplification. They are the two properties that are connected. So we see here, in an image, for example, here, what you see schematically is this kind of cavity. So this is now a horizontal cavity. You see these blue and red layers, which is like a mil-fade, if you like, but this kind of mil-fade confines light in the very small green area in between. And in this kind of device, we can send a single photon and we can use a process of amplification, which practically creates this polarity and compensates to amplify it and create a lot of photons coming out. And we can do this very fast. So this is what Darius was saying. We can do it down to terahertz rates. So please carry on. Well, so that's, yeah, that's you said, if I understood correctly, a liquid droplet of light, is that right? That's, I think that's, I don't know what our audience is thinking there, but to me, it's completely impossible to imagine how can you create a liquid droplet of light, right? It's like already light. I remember this whole debate I was reading about in high school when I was studying physics, I about the wave particle duality of light, right? People didn't know for the longest time whether light was a particle or a wave or both or what. And now you guys are adding this fifth state of matter into the mix. That's, I think you're just complicating, complicating things even more. Actually, we simplified in some way, I would say, because for the audience, if you have two laser pointers, yes, and you cross the beams of two laser pointers and like Star Wars, they don't actually touch each other. You see no interaction, yes? So light with light in free space does not interact. These saber swords or lasers, actually you cross one pointer through the other, but now by adding a matter component to light and creating this kind of liquid light, now you add interactions in the system, so practically light interacts more efficient with light, and that's how then you can use this to manipulate information. Wow, I think you just completely killed the Star Wars there for me forever. And we should invite George Lucas to watch a replay of the discussion. But speaking of lasers though, so you work with lasers, right? So this work involves lasers, if I understand correctly, and funny enough, I don't know if anybody watching us right now is based in Russia, but you are in Russia now, right? And it was the Soviets that pioneered laser research half a century ago, right? So I just wonder how it feels for you to kind of work on lasers in Russia being in the country where that pioneered this really cool invention. Yes, actually in Skoltec, this is a new university in Moscow, which was established in collaboration with MIT. This is a view of the lab, which we set up in 2016, we started, we moved actually into the building in 2016, and we set up a lab which is dedicated to hybrid photonic. So practically this kind of liquid light, it's fundamental properties and applications. And in Russia, they have, as you say, a lot of history on lasers, with the semiconductor laser and the late Professor Alferov, who actually visited us in the lab. So the inventor of the semiconductor laser, he was there when we were setting up, super excited about, you know, that this research is really moving forward. And yes, we are using lasers in our devices. As you saw in the lab, there is lots of equipment. We are using lasers which are unlike pointers. They use very short pulses. This is really, you know, like a billion of a second in width, these pulses. So very narrow pulses of light so that you can do very fast manipulation of information. And what we saw there earlier, it was actually a photo of the three lead authors of this work. These are three colleagues from Russia who really made this happen in this lab that we saw. And working in Russia, it is actually, especially in Skoltec, it is like working in any other leading research institute. But the advantage for me that I have worked also in Europe for many years is that, you know, it is the human capital. The people have a very strong background, a very strong science background. So combining experimental physics with very strong theoretical background has been extremely good for us. And it really helped dramatically to lead to this discovery that we are discussing today. Wow, yeah, super cool. Because actually we forgot to mention that this discovery, this optical switch is being, the paper is being published in Nature, the leading science journal, right? So that's really quite an amazing achievement. And so, yeah, if we go back to Darius now, and so one question I would like to ask you, Darius, if you could just tell us, how close are we to actually, you know, starting using this cool technology or is it like in the very, very early stages right now? Darius, I think Darius might be having technical issues there. So Pavlos, I don't know if you maybe want to step in. Yes, yes, so the, sorry, to really go back to your question, can you repeat this? Yeah, how close are we to actually using this technology? So this is a technology at its infancy, yes? So we just discovered that we can actually do this. We can switch this kind of liquid droplets on and off using a single photon. And what we have been very much interested is in the physics behind, in the fundamental science behind that enables this process. So now that we know that the process is there, this is the first stepping, the first step if you like, now we are working towards going from having one switch, one transistor to creating a race of these transistors, connecting this race of these transistors, building if you like polarity on circuits. So circuits of these liquid light droplets. And from there, you can use them, this very fast speed of switching for making some basic operations. If we go many years down the line, 10, 20 years down the line, it is very hard to make accurate predictions, but I can tell you that something that can switch on and off so fast, and if you can have lots of them interconnected in a circuit, you could use it as an accelerator as a device which performs some specific function, but much faster than any of our current supercomputers. Okay, cool. Well, and it's also not the first time you're doing this research, right? I mean, specifically this, of course, it's breakthrough, but you've worked with light before, right? Oh yes, I've been working all my career with light and we started working in polaritonics 20 years ago in this kind of field of liquid light and its applications. But this collaboration with IBM that we started a few years ago, it has been extremely fruitful because you have developed some amazing technologies which then we combine with the capabilities that we have in our labs, both at SCOTEC and at the University of Southampton. And yeah, in 2019, we have the first oloptical transistor operating at room temperature. And now we can show that we can switch it on and off down to almost one photon if you like. Cool. Well, I wonder if Darius is back online now. Maybe we should check if he's there. Darius. Hello everybody, can you hear me? Wonderful. Yes, yes. Perfect. So Darius, in your view, why is this research super important, I guess, if you can just tell us where we are going with this technology and kind of just to pick up on what Pavlos was just explaining, how close we are to making it widely available. Yeah, so unfortunately I dropped a little bit with Pavlos, but I can tell like that for years, the people were looking at this light, like the ways how to do switch light with light. Yeah, and really the main challenge there was really that it's very hard to do that. I mean, we need to somehow get this interaction going. So I mean, we were looking at the ways how to mediate this interaction that with a very single photon, like in our case here, we would be able to switch many of those. So yeah, so I think this is really at the moment, like this work that we are here, what we demonstrated is really like a really kind of a groundbreaking step towards the future. So I think it's really like motivates like researchers like others, like the students also to like look into this field. So yeah, for me it's a fascinating. Absolutely. No, super cool. And I mean, one possibility incorrect me if I'm wrong, but I guess the possibilities are quite limitless as well. And I wonder if we could actually extend it to quantum computing in the future. What's your view? Yeah, I mean, you know, nowadays quantum computers, they are like, I mean, in the future, let's say if the quantum computers would like to like communicate with the quantum computers, I mean, they will need to also like to transduce the microwave frequencies to optical domain. So for example, these quantum computers start to like kind of communicate with the photons. So maybe at this point really like in the future, this kind of fast and efficient like switches could maybe help there. But yet again, I mean, this is very far, far in the future. And at the moment, we're really like at the fundamental level of where we're really like switching our photon with photons with very low powers. Cool. Great. I just, before we go to the next question from me, I just want to encourage the audience to please ask questions in the chat and our chat experts to please pass the questions to our speakers here as well. That would be great if the speakers could also answer some of the questions. So if you could, you know, send them our way, that would be, that would be super helpful. But for now, while we are waiting, if I can maybe ask Pavlos the same kind of question on quantum computing, right? Like we were chatting before and you had quite an interesting explanation, I think as well that I think our audience may really enjoy Pavlos. Yes. So, well, you know, there is a lot of discussion about quantum computing and IBM is pioneering in superconducting Q-beats quantum computers. There are different platforms for quantum computers, but I think really for the audience, it is like a black box. So I wanted to give you a description of a quantum computer, which I'm using with my children when I tell them that they work on quantum computing. So let's start with a classical computer where we have electronic transistors. When you have an electronic transistor, you're using electrons to transfer bits of information. Yes, so we have bits one and zero. You have an electron transfer information or not. And you start building something by electrons carrying bricks. But when exactly each transistor will switch on and off, we can compensate is not so important. Now in a quantum computer, you're using Q-beats. You don't use ones and zeros. And Q-beats, they have different properties. They really, for Q-beats, what really matters is phase, is synchronicity. But practically when you couple to Q-beats, they are in phase. They are dancing together, you know, like the arms of Czeska when she's dancing ballet. So now when you go from two Q-beats to many Q-beats that you want to build and you don't want to have just 100, you want to have tens of thousands in order to do something sensible, it is like you are coordinating an orchestra. So a quantum computer would need to have all these Q-beats singing in phase. It is like all the instruments if an orchestra, each of them can do something slightly different, but they all need to be synchronized in some way. Now with Q-beats, there is a lot of work and with quantum computers, a lot of work, different platforms of how we can make, put more and more Q-beats and maintain this synchronicity. This is a very big issue now. Now let's go 10 years down the line where you will have your quantum computers in IBM and now we have two of these quantum computers. So look at these two quantum computers as two symphonic orchestras. So it is like having an orchestra in the Bolsoi and another one in the new Bolsoi and you want somehow to synchronize the two. For that you would need a device or you would need a medium that would transfer if you like the beat. So you take a violinist who takes the beat from one orchestra, walks from one concert theater to the next and then the two orchestras, they are synchronized. But it is very important that the phase, the coherence, the synchronicity is not lost while this guy is walking from one orchestra to the other. And the best way to do that is by using photons. Electrons interact very much with other electrons and they lose this information of phase, yes? They be synchronized. But photons, they are very pure. And as I said before, a photon in a free medium does not interact with anything. So it doesn't lose if you like the coherence, the beat of the first orchestra. So through these photons, you can connect to quantum computers. And of course, when you are dealing with one photon or few photons, then you have the issue that photons can get lost. And that's where you need this kind of devices where they take one photon and they create many photons with the same properties. So you can amplify if you like the beat, transfer it and make two quantum computers communicate. Now, we are very far from that. This is really, if you like, this is in the future, people can imagine different applications. But since we have now the schematic that we were just showing, I wanted to say that what we are trying to do now, and if we can go back to the schematic is that we have these single photon switches, individual ones, and what we are trying to do is to put them in an array where we can connect them together. We are not aiming for millions right now. We are aiming for a few dozens of them where they talk with each other and we built a basic circuit of liquid light droplets as you see on the schematic. Thank you. Wow, that's super cool. And I like the colors on the schematic, something I would definitely put on my desktop wallpaper, for sure. But thank you for that explanation, Pavel. Now we are finally getting questions here for you guys and one here is for Darius. So Darius, could you explain a little bit more in detail what is the environment that the switch actually works in? Is it cryogenic? Is it atmospheric? Is it vacuum? Well, the experiment actually was done at room temperature, so ambient conditions. So this material that we use is really special. So to say, yeah, it supports this light matter interactions at room temperature, which is like unique to what we are doing to this work. And yeah, I mean, the whole device is tailored according to that material. Okay, cool, room temperature, well, that's even... Yeah, that makes life easier. Exactly, exactly. To scale it, I guess, as well in the future, right? And somebody else is asking in the chat here, or actually maybe it's the same user here called Lightning Rod QQQ, very cool nickname, by the way. So Lightning Rod is actually asking, what is the current physical footprint of the switch? Yeah, so the devices that we here had is like on the order of 10 microns, which is like one-fifth of a humer here in the diameter. But I mean, this is still a very large device if we now compare this to electronics, so transistor. So a transistor could be like 1,000 times smaller than that, like in the humer here diameter. But despite that, I mean, there could be also like approaches in the future where we could really benefit like that if we could build like circuits that would not really benefit from the size, but let's say we could have a few of these elements, but if they could be, let's say run very fast and very efficient, I mean, this could be also like really a great thing in the future. But yet again, yeah, now it's really like, that we only like think about like one, and then as Pavlos mentioned, like coupling like three or so when having them like efficiently operated. Cool, cool. Yeah, well, let's go back to Pavlos and I've got a question for you. And now that we're waiting for questions in the chat, what is the switch actually made of? The switch is actually surprisingly for talking about a transistor, it is made of an organic material. So inside this cavity where we'll confine light, instead of using your traditional silicon semiconductor, which actually does not interact so well with light and does not emit light, we're using an organic material, which was designed very long time ago, more than 20 years. Our colleague will reset from Wuppertal University in Germany. He designed a polymer, which looks like a ladder, practically, so it is a ladder type polymer, which is very robust to its interactions with light. And that actually was one of the key elements that enabled us to work and do research, very intense research, which lasts for many years on this material in this cavity and really come to the demonstration of all optical transistors and single photon switch. And that tells you something about the history of science. We are very happy with our result now, but it is the result which is based on the research efforts of many people from many different places of the world. And in some way, incoherently initially, and then with some coherence, some synchronicity, we start collaborating and we come to the outcome, which is the single photon switch that we are discussing now. So it is an organic material from all types of things that IBM would use here. Cool, cool, very cool. And thanks for that. So we've got another question here from a user called Shiv Aria. I hope I'm pronouncing the name correctly. What type of lights are they using in making the switch? I'm guessing probably the meaning is probably not making, but in operating the switch, what do you guys, how would you answer that? Who wants to take it on Darius? Yeah, so what we are actually using is that we use a kind of like a create, so we excite our device. So still we use quite a lot of power to create, to excite our device. So the power budget is still large. However, then we send a single photon to our device and that device triggers like an avalanche process. So basically all this photo, the energy that we use to excite this device is in there. And then when this one photon comes, it basically dictates all the rest of the photons that are there already, like in excited. So they kind of like, we stimulate them. So there's like, they go as one, in one big group. So they are emitted. So we kind of control with like single photons. We are able to really like, force the whole group to move together like in phase. Wow, okay. And so just again for me to kind of understand and I wonder maybe the audience is also asking themselves this question, but so basically this switch would make my phone, my computer be much faster, right? So the pages would load faster or what exactly would actually change? Like, you know, if you just use an example of technology we have today. So yes, it is true that when we are talking about computers, we want them to be faster and faster. And there is, but there are limits. And the kind of device that we made here makes things so fast that would make no difference to any application that has a human interface. Yes, it really goes beyond anything that would make a difference to you, but it is not even aimed for a desktop or a mobile phone, you know, a smartphone or something like that. It is really aimed for a very specific class of computations if you like or applications, which require very high speeds beyond what we can get now with our current computers or supercomputers. So here I can say, for example, that, you know, many people in the audience will be familiar with Moore's law where we double the number of transistors every two years. But there is another law, which is called then a scaling law, which is not so famous because it stopped to apply back in 2005. And that law was the one that was saying that the speed is actually doubling every two years. And that stopped back in 2005 with your computers nowadays having more or less the same speed, three to five gigahertz as it was 15, 16 years ago. So when it comes to speed, there are some hard limits which come mostly from the heat that your processors, your transistors emit, yeah? And that is actually a severe limitation which fixes the speed of electronic transistors with optical transistors. There is practically, there is very little heat if you like. We do not have such limitations. So now we can bring the speed of switching from three to five gigahertz to near a teraheads, yeah? So this is between a hundred and a thousand times faster than the fastest current switch, electronic switch, if you like. And that will have applications, but not on devices like the ones that you refer to. There are particular sets of data analysis that you want to do, which needs to be very fast when you are looking for correlations of signal. So the kind of devices that we are talking about is not smartphones, but what we call accelerators, yeah? They accelerate information processing for particular applications. Okay, cool. And also earlier in the discussion, I guess one of you I think mentioned also the energy consumption, right? So they are faster, but they also consume less energy, is that right? Yeah. There is, right? There is. Yeah, so indeed, so the idea of here is really that if you compare to regular transistors that the one that we have presented here and our latest research is that it's 10 times, consumes 10 times less power to switch, compared to the nowadays transistors, like to the state of the art. And yeah, so exactly that the, and then it really triggers this avalanche process. Yeah, that's actually an interesting point because well, at IBM, for instance, as you, Darius, you probably know very well, we also work a lot with AI and AI hardware, right? And for AI specifically, AI is getting more and more sophisticated, but energy consumption is also growing. So I wonder, would that work for some AI applications in the future as well? Potentially, potentially, this is not something that we are having in mind now. We really need to, what we are doing now, we are looking at the basic fundamental mechanisms, you know, what it is that gives us this kind of amplification, what makes it so fast? What are the processes that happen in this polymer that I was describing, yes? Which allow us now to go beyond what we can do with electronic transistors. So our research for now, and for the few years ahead, I can tell you that we'll be focusing on the fundamental limitations of applying such a process as a single photon switch to scaling it up. How many of these can we put together? Are there hard limits to that? And when it comes to the power consumption, it is actually 10 to 100 times less consuming the energy that we need to put in order to switch this optical switch. So it goes down to one auto-jowl, and one auto-jowl, well, what is a jowl for the audience? One jowl counts energy in physics, and it is if you had, you know, if you had a resistance of one ohm and you pass a current of one ohm for one second, that would give you one jowl. And the energy that we are using to switch this, it is a quintillion of one jowl. So put 18 zeros together, and one at the end, this is the amount of energy that is needed to switch this transistor on and off. So really down to one photon, which is something that we cannot really comprehend in so easily. We cannot see a single photon so easily if you like. We use special devices. Wow, wow, that's super impressive. Question from the chat here. Have you guys been successful in making a gadget using light already? Yeah, so we are working at the moment as well, trying to maybe even connect several of those, like integrate of them. We are also working with Paulus together to integrate these devices together. So like, but yeah, so the gadget would be, I would say not really a gadget, but more like a chip that could do like gate operates, operations like we showed like our previous Nature Photonics paper. But now if you could like push this towards, like I used to know how that we achieve now with this, I mean, this work, I mean, we could make the mesh efficiently and make this efficient logic gates. Yeah, then I mean, that would be the, I would say the next step. But as like the, I would say the gadgets as this, I mean, yeah, so this is a hard to imagine currently as is this really a fundamental research, but I mean, you could imagine like, yeah, to have like a few gates that could be run at this low power consumption and very fast. Wow, yeah. That's really impressive. So another question from the chat here, actually quite an interesting one. Is the optical switch analogous to the qubit? And I guess in a way, because we were talking about quantum computing, right, and photon is the quantum of electromagnetic field. That would be, yeah, what do you guys think? It is not analogous to the qubit at this point. It is analogous to a bit, if you like, yeah? So it is analogous to the classical bit, one, zero. So you switch it on, you switch it off. But now you can do this with one photon, with one auto job, where if you were to use an electronic transistor, you would be switching on and off with 100 times the energy, yeah? It would require 100 times the energy to switch it on and off. Of course, it sounds like we have already discovered the green agenda for artificial intelligence, et cetera, et cetera, but there are limitations and people would be aware that, you know, such an optical transistor, it has issues with scalability. We will never, we know this from now. There are hardly any, we will never be able to put trillions of transistors on a microchip, yeah? We will be putting few hundreds of them, few thousand, tens of thousands, but we would never really reach the scalability and the density of electronic transistors. And when it comes, when it comes to qubits, this is research for the future. So it is very early days for us to say, if we can use the fact that we are dealing with one photon in order to use this for qubits and quantum computation. Okay, cool. Well, actually going back to what we were talking about earlier, the, these really cool particles who were describing Paolo's excitant polaritons, right? So they are technically classified as bosons, right? And I remember I visited CERN a couple of times. And of course, you know, the, what CERN is most known for is the famous Higgs boson, right? So what's, how, you know, similar are these particles to say the Higgs or other bosons? From a physicist's point of view, they are very similar. So a Higgs boson is a, you know, an elementary particle. A photon is a boson, yeah? So a photon is, when we say a single photon, what is a photon? It is the smallest packet of energy that you can create at a particular color of light. Yeah, at a particular frequency of light. So it is the smallest quantum of energy that you can have. Wacket of energy, quantum is a packet practically. And a photon is a boson, the same way with the Higgs boson, which actually has a very counter-intuitive property. So in nature, it is very simple. This is a, you know, a very simple distinction. There are two types of particles. They are fermions and they are bosons. People have the standard of electrons and protons. These are fermions. You cannot take two electrons and put them together, they impale each other. But when you deal with photons and bosons in general, they like to be at the same state. Bosons are much more loving particles. You know, they like to occupy exactly the same state. We call it the quantum state. And this is really part of the magic that we used in order to create this switch. So bosons, if you have one boson and there is a possibility for more bosons to come and occupy the same state, they will do that. And they will create a macroscopic state, you know, a group of bosons that they behave all together like one. So it is back to being in concert, yeah? They are all synchronized. They are all characterized by the same way. And this process of relaxation, of putting more bosons together, is what we used in order to create this switch. So we put one boson in, which is one photon, and then 23,000 more bosons are coming in. So we can amplify, if you like, light by a factor of 23,000. This is a very large amplification number. But the process behind, it is actually this affinity of bosons to a boson which is at the lower state. They all go and occupy the same state in the system. And that's what we used in order to embed this kind of strong nonlinearity in the system which allows for this single boson switch in the application. Cool, cool. Well, I actually have a t-shirt at home with this table, you know, defecting bosons and fermions and everything. And I should have worn that instead of this, but although this is also pretty cool, right? So going back to the chat here, Cheryl is asking, and maybe Darius, you can pick this one up. Why are you guys comparing the speed to transistors rather than fiber optics? That's a good one. Yeah, so, I mean, in the end, we want to do classical logic with this device. So that's why we want to really, that's why we are comparing this to a transistor device. I mean, in the end, yes, I mean, we are using light. And of course, these switches that we have here could be potentially useful in the future also for optical communications. But, I mean, of course, in the long term, what we envision is also really to like build like some few gates or so out of these devices. So that's why, maybe Pavlos, you want to also comment on this, so what's your take? Yes, so an optical fiber, people understand optical fibers, it carries, you know, an optical signal and can do this very fast with a speed of light in the optical fiber. But actually in an optical fiber, you cannot, for so far, you cannot integrate something that manipulates the information that you carry. So you send a button down an optical fiber and it is like a hose, it will come out from the other end. But what we are doing now, so fibers are good for optical interconnects if you like, but what we are doing, we are using light to interact with liquid light, with these polaritons, in order to create transistor switches that then you can put together and as we demonstrated already, you can put them together in logic gates. So back in 2019, we saw that we can use light to enter in an architecture that brings in logic gates such as and or logic gates. The mental logic gates which allow you to do logic. And if you want to process information or to make a calculation, you need to have logic. Just funneling light is not enough. You need to be able to use it for processing of information. Okay, thanks, yeah. Thanks for that, Paoloz, that's cool. And there's a question here in the chat for Darius, actually from Timur. And Timur is asking, from the fabrication point of view, could such type of the switch be produced from any organic materials? Is the fabrication of the structures cheap? And actually before you answer, I'm also kind of curious, in terms of this organic polymer material, it could be rather fragile, right? So would that be also a problem to build actually reliable devices? Yeah, so this goes back to decades ago. So start, we can like maybe think of like OLED TV. So I mean, this technology was started 30 years ago or so. And back then these materials, this organic materials, which are, I mean, rather, I mean also go in the same direction. I mean, they were also like lasting only like for a few hours, even if that, you know? And then this technology over all these years, it really matured to the point where we can really like go and buy a TV, which is like last for 10,000 hours now. Now this is exactly, this technology was really over years of research where like fabrication has to really had to be mastered. Also like encapsulation techniques and also material properties of this. But that was true also for our material here, which is organic polymer. And yeah, I mean, this is like, it's still at the research level, but I mean, at the moment, even this material is like, like we have now, it's really good enough like that these timescales that we are using it for that we can really work on this fundamental physics and really explore the there, like what's possible with it and what kind of maybe gates or like physics we could see or establish. Now coming to the question about the, is it like, is this only this material is possible? Well, no, I mean, these materials are really tailor-crafted for specific reason. There are fundamental reasons for that. So first of all, it has to support these light matter interactions and there are specific conditions for that. So as we discussed before, we use polaritons. So this means like light is interacting with the medium there and that medium has specific properties. So meaning that it has to support this interaction with this light. So, and there are also other limitations like and to, well, there are specific stores that it has to be on a room temperature so that there are also some physical conditions that apply. But in the end, like home propagation point of view, we are still developing of it. And like in OLEDs, well, we really have to look encapsulation of this material, how we can also make it stable. And yeah, so I believe that in the future, I think that this could be also very well developed. Cool. Sorry, just wanted to fully answer the question. Was that, is it cheap? I think it was also like, so you know, it's really at the fundamental level. So I mean, you couldn't like, it's not, I mean, one still needs to invest into this work to be able to do. So we need really to engineer like this encapsulation techniques and then really like engineer this cavities that we use in our device that they are supporting. There are like this fabrication techniques, they work together with this active material that we use that it's, you know, they can like, we could make them together. So they don't conflict with each other. So yeah, so this is more or less my take on that. But I mean, in the future perspectives, I see that there is really a way, a lot of what we can learn, and especially from like other research fields which were developed for decades now. Yeah, great. Actually somebody here is asking, well, you answered part of the question already, how robust is the organic material? So you answered that the second part of the question from this guy was a really cool nickname, Bruce Billis. Interesting, reminds me. Reminds me and many others of famous actor, of course. Anyway, he's asking, does it age well? It ages better than most of the materials that we have been using in the last 20 years in organic polaritonics. So IBM in collaboration with the University of Uppertal have done an amazing job to make some of the best organic microcoveries as we call these devices, organic devices in the world so far. So we can answer the question in terms of a researcher, we have been working on this device for many years and it is still working as in day one. So Professor Ulrich Sepp, he really managed to engineer an amazing molecule which is extremely photostable and has enabled this field because as we started the discussion area, IBM demonstrated this kind of coherent wave of liquid light, the first liquid light droplet back in 2014 using this particular device, this particular sample that we are using up to now. When it comes to organic LEDs, organic displays, they age and sometimes they even age faster than the device that we are playing with now. There is another question that has come an interesting one from John Blomart and Lerner Dude, if you're interested, Tatiya, to... Yes, indeed. So why don't we go to that? So hello, why don't you tell us how fast is the amplification process? So there is, yes. So the amplification process takes place in a sub picosecond time scale. So this is less than one trillion of a second. So if you want it, for example, to see it in terms of frequency, one less than faster than a telephoto, I guess. So we can switch on the amplification very fast. The limitation on the switch, on how fast the switch can be, it is not on the switching on, which is practically instant for anything that we can interface with. But it is on the switching off, which takes a bit longer. And that's really where we say that it can go up to one pair of heads. But if the switching on goes as fast as the switching off, we could go to multiple pair of heads, yes, as operating frequencies for this kind of switch. And that relates to this interesting question that came from Lerner, do that thing, which is this could be used for something that requires low latency. Potentially, yes. You need to be able to interface in the right way with it in some way that you can read and write the signal as fast at least as the switch is switching on and off. Cool. Okay. Well, in the last five minutes, I guess it would be good to talk about the history a little bit of optical computing because Darius mentioned previously that of course this research on optical circuits has been going on for quite some time. So how is this research different? Like if you were to sum up what you've done now, based on what's been done by other researchers and you guys as well in the past few years, what is the actual kind of break through here that is different from everything else? Darius? Yeah, so I mean, people were using now like a light matter interactions as well for this, but they're mostly also used in weak light matter coupling regime, so-called. Here in the sense we use this quasi-particles polaritons which work in a strong light matter interaction regime as we discussed before. And yeah, I mean, really like the breakthrough and this ability to really push this towards this super low energy consumption per transistor is really a key and that enables next steps where we could imagine like having multiple of these transistors together working, yeah. And what are the main challenges, would you say right now in these optical switches? Yeah, so first of all, of course, one is the material. There we are actually working with also with Pavlos and we are working also other materials such as perovskite, we also perovskite that we also had recently a nature article there that we could maybe use other materials that may be more suitable towards for using these applications more in general, like to increase this light matter interaction. So making this process even like maybe easier to use but also like integrating these devices. I mean, we need to be able to connect them together somehow, so for example, coupling these two different transistors. So also on this, we had like a paper also recently where we showed like vape guys that we could envision that we could use how to couple these transistors together. So and in general, like the power consumption, like how we could not not not only like the switching but also power budget. I mean, it's the challenge is really how to reduce that because we are still now the total power budget is still millions of the photons. But I mean, we still are able to switch them but maybe reduce them. And then like of course in the fabrication point of view that's what really where the advancement has to be done such that we really could like integrate them and like have several, several them together. Okay, cool. And just I guess again, maybe to talk about the applications a bit more. So I know we touched on this before but I'm sure lots of people are interested in where it's actually going to go, right? So can we use it in computers or telecom devices? What are other possible applications if you could just kind of reiterate and sum it all up? So who wants to take it, Pavos? That actually top to you. I mean, we can switch. Yeah, all right. So really the work that we are presenting in this nature of application and you can keep various on the chat here in case he wants to add is that it's the outcome of many years of research on the fundamental science that underlies the processes that we discussed. And the talking of applications, it is we are realistically for the next five years we are working together with IBM and several other European partners in creating a race of these switches. Yes, as I saw you previously on this image to connect several of these droplets. We are working to connect several of these droplets both for logic circuits, which we discussed. So optical computing in the sense of logic but we are also connecting this kind of liquid light droplets for a different type of computation which is called analog computing. There is a class of problems in nature where there is no intuition that can give you the answer. It is not about solving it as we say algorithmically, yeah? You need to have to try different solutions and then find the one that solves the problem. And for this kind of problems we are using what is called the simulator and the simulator is a completely different like quantum simulators, a completely different class of computers that solve particular problems. So with liquid light, we are also creating a race of droplets in order to really map on this system complex problems that scale exponentially as you increase the number of variables in computation time, which are completely intractable with current supercomputers and try to really make this liquid light computing to give us, to help us to find answers to these complex problems. So if you like liquid light computing has two arms, one is on logic, optical logic, optical computing as we discussed so far but it is also simulation, quantum simulation for solving non-algorithmic problems in the CPS service. Cool, great. This is perfect. We are out of time but thank you so much guys for a fantastic discussion. Thanks to our experts in the chat and of course to the audience that joined us from around the world and people in the audience, please do send us your comments, ideas, suggestions for future webinars as well. You can find me on Twitter, you can find both experts here on Twitter as well and we'll see you next month. Thank you and goodbye.