WEBVTT 1 00:00:05.170 --> 00:00:16.750 STFC-RAL-CR03 R61: Welcome, good morning, everyone. Welcome to this, PPD and QCC joint seminar. Title is Factor Split and Quantum Quicks. 2 00:00:17.120 --> 00:00:36.289 STFC-RAL-CR03 R61: Our speaker. Welcome, David, and thank you for being such a sport yesterday through all of our adventures. If you want to know about it, I would be happy to tell it at lunchtime. So, what our speaker, David, is a molecular astrophysicist with interest in explanatory biosignature. 3 00:00:36.670 --> 00:00:38.939 STFC-RAL-CR03 R61: Molecules in extreme environments. 4 00:00:39.140 --> 00:00:49.230 STFC-RAL-CR03 R61: quantum computing and machine learning. He is an award-winning senior lecturer in the molecular physics and psychochemistry at the University of Hull. 5 00:00:49.680 --> 00:00:52.169 STFC-RAL-CR03 R61: And teaches advanced quantum mechanics. 6 00:00:52.590 --> 00:00:56.910 STFC-RAL-CR03 R61: Astrochemistry, data science, and scientific computing. 7 00:00:58.220 --> 00:01:03.340 STFC-RAL-CR03 R61: He holds a biochemistry degree, from, University of Bizanne. 8 00:01:03.420 --> 00:01:11.209 STFC-RAL-CR03 R61: a PhD in theoretical chemistry from UCL, and a German habilitation in theoretical chemistry. 9 00:01:11.260 --> 00:01:23.809 STFC-RAL-CR03 R61: And David has authored over 70 peer-reviewed publications and has 25-plus experience… 25-plus years of experience in developing high-performance computing solutions. 10 00:01:24.020 --> 00:01:27.030 STFC-RAL-CR03 R61: For problems in quantum chemistry. 11 00:01:27.260 --> 00:01:29.930 STFC-RAL-CR03 R61: Molecular Physics and astrochemistry. 12 00:01:30.420 --> 00:01:37.340 STFC-RAL-CR03 R61: He is an associate editor of Frontiers in astronomy and Space Science, 13 00:01:37.560 --> 00:01:41.109 STFC-RAL-CR03 R61: Mainly it's a strong chemistry division. 14 00:01:41.830 --> 00:01:51.830 STFC-RAL-CR03 R61: the principal UK investigator for the EU ETMOS project, and a collaboration partner for the KM3Net Neutronics program. 15 00:01:52.220 --> 00:01:55.710 STFC-RAL-CR03 R61: He has many other accolades in his, 16 00:01:56.130 --> 00:02:05.279 STFC-RAL-CR03 R61: In CB, but I will just skip them for now, and let's get to the seminar. Thank you, David, and welcome, the speaker. 17 00:02:08.699 --> 00:02:18.339 STFC-RAL-CR03 R61: Thank you, thank you very much. I guess that was a firelander? Yes. So, we do. Okay, well, thank you very much for inviting me here today. 18 00:02:18.450 --> 00:02:25.470 STFC-RAL-CR03 R61: It was a Louvrenderful statement, it's okay. So, I think… 19 00:02:25.930 --> 00:02:36.430 STFC-RAL-CR03 R61: despite, I think, all, all the base interests, that you mentioned, also have, 20 00:02:36.810 --> 00:02:39.649 STFC-RAL-CR03 R61: Quite a lot of interest in neutrino. 21 00:02:39.810 --> 00:02:46.500 STFC-RAL-CR03 R61: physics, and I think this is probably also why it feels like it's a good, good idea to come in. 22 00:02:46.750 --> 00:02:53.350 STFC-RAL-CR03 R61: book, do you guys do any? So, because… 23 00:02:53.510 --> 00:03:04.510 STFC-RAL-CR03 R61: This talk will touch on lots of physics, particle physics, quantum computing, I thought I'd have a bit of a recap of 24 00:03:04.790 --> 00:03:09.560 STFC-RAL-CR03 R61: everything as I go along. Any astrophysicists in the audience? 25 00:03:11.100 --> 00:03:31.070 STFC-RAL-CR03 R61: Oh, there you go, there you go. One or two. I think usually, usually it's… this is a completely different thing. Usually, I have to explain a lot of, a lot of the particle physics in the quantum computing, because everyone knows the astronomy. So, 26 00:03:31.290 --> 00:03:42.850 STFC-RAL-CR03 R61: I've pulled a couple of things from our, astrophysics sectors, just to explain to you what that kind of image is, and why we're interested in looking at, 27 00:03:43.240 --> 00:03:45.519 STFC-RAL-CR03 R61: Retrios, particularly in the sort of… 28 00:03:45.740 --> 00:03:48.810 STFC-RAL-CR03 R61: sort of dense neutrino regime. So. 29 00:03:49.560 --> 00:04:02.659 STFC-RAL-CR03 R61: It started, I think, a while ago when we started looking at, explosion of massive stars. So, what happens… this is what eventually leads to what we call a supernova, which are one of these 30 00:04:02.960 --> 00:04:07.700 STFC-RAL-CR03 R61: Great fireworks that you see, in… 31 00:04:09.770 --> 00:04:17.940 STFC-RAL-CR03 R61: Well, I suppose we've gotten up quite a few pictures, and we can see signs of lots of 32 00:04:17.940 --> 00:04:27.349 STFC-RAL-CR03 R61: these sort of events, particularly if you're from the neutrino community, we like those events, because they will usually generate lots and lots and lots of neutrinos. So. 33 00:04:27.350 --> 00:04:43.140 STFC-RAL-CR03 R61: This usually works like this, where the star eventually runs out of fuel, so you have to take a reasonably big star, something that's about 8 times the mass of our sun, and it runs through all of the processes that it has that's making us use of 34 00:04:43.140 --> 00:04:43.850 STFC-RAL-CR03 R61: Listen. 35 00:04:44.300 --> 00:04:49.610 STFC-RAL-CR03 R61: nuclei's… One, it gets to iron. Iron is essentially 36 00:04:50.710 --> 00:04:58.620 STFC-RAL-CR03 R61: The stable stop point at which the star can really extract much more energy out of fusion, so 37 00:04:59.350 --> 00:05:02.590 STFC-RAL-CR03 R61: The call stops. Essentially, the fusion stops. 38 00:05:03.040 --> 00:05:09.729 STFC-RAL-CR03 R61: And because that was balancing the gravitational pressure, new course starts to be sure to contract. 39 00:05:10.280 --> 00:05:26.449 STFC-RAL-CR03 R61: Usually, stars do that all the time, right? So when that happens, usually it's fine, because that then reignites the fusion, and then it continues again. That's when we make the shells. But here, because we are iron, it just constructs… contracts and just goes, ugh, I can't really do very much. 40 00:05:27.850 --> 00:05:44.469 STFC-RAL-CR03 R61: while that's happening, the last part of silicon burden continues depositing iron into the core until we reach a critical mass, and at that stage, it starts decides that it has enough particular the core, and I'm just gonna collapse. So it collapses, cools down. 41 00:05:45.000 --> 00:05:53.600 STFC-RAL-CR03 R61: And generates… this is quite quick. This happens within about a second. The staff starts to collapse, the court collapses. 42 00:05:53.990 --> 00:06:00.719 STFC-RAL-CR03 R61: And we have processes like neutralisations, photos and integration that starts releasing all sorts of nutrients. 43 00:06:02.050 --> 00:06:09.450 STFC-RAL-CR03 R61: At one stage, Can you imagine this week's core collapsing? 44 00:06:09.740 --> 00:06:15.479 STFC-RAL-CR03 R61: Things get smaller and smaller and smaller, and of course, at one stage, the nuclear forces just go, well, hang on. 45 00:06:15.660 --> 00:06:32.510 STFC-RAL-CR03 R61: I mean, we're nice, but we're not that nice. At one stage, we're going to stop compressing this, so the nuclear force then essentially, of course, is forcing the core to rebound, and essentially a shock wave that is then sent back out, which is what is 46 00:06:32.800 --> 00:06:41.620 STFC-RAL-CR03 R61: Fleet shown here on the… On the right, that causes the rebound, or called rebound shock. 47 00:06:43.400 --> 00:06:56.349 STFC-RAL-CR03 R61: We don't think that is then the explosion of our supernova, but what happens is this shock then encounters the rest of the matter that keeps falling into the core, because gravitation keeps pulling things out. So, eventually. 48 00:06:56.790 --> 00:06:59.940 STFC-RAL-CR03 R61: and the truck propagates outwards, I think that's what we have. 49 00:07:00.040 --> 00:07:04.090 STFC-RAL-CR03 R61: on this nice diagram from Janka here, 50 00:07:04.260 --> 00:07:08.990 STFC-RAL-CR03 R61: The shock sort of propagates forward, and then stuff keeps 51 00:07:09.890 --> 00:07:19.709 STFC-RAL-CR03 R61: Coming down, which means that, essentially, with… I… stalled shock, so… 52 00:07:20.330 --> 00:07:24.530 STFC-RAL-CR03 R61: shop front, and they fully might end up in some sort of 53 00:07:24.790 --> 00:07:29.850 STFC-RAL-CR03 R61: With equilibrium for not very long, The call continues to become 54 00:07:30.500 --> 00:07:36.249 STFC-RAL-CR03 R61: Trying to become a literal star, essentially. And then, you have, sort of, two options. 55 00:07:36.860 --> 00:07:40.429 STFC-RAL-CR03 R61: If you can put more energy into that shock. 56 00:07:40.570 --> 00:07:46.239 STFC-RAL-CR03 R61: you will go supernova, and you will have an explosion. If you don't. 57 00:07:46.350 --> 00:08:03.230 STFC-RAL-CR03 R61: Eventually, you become a super bloated neutron star. This is not whatso physicists really call it, but that's what I call it. And then that is what is going to become a black hole eventually, because you… you have also mass units of neutron stars. 58 00:08:03.570 --> 00:08:06.119 STFC-RAL-CR03 R61: So you have essentially those two options. 59 00:08:06.270 --> 00:08:25.579 STFC-RAL-CR03 R61: And for a while, people were wondering, well, how do we know which of the two options are we going to be? The weird thing is we're not seeing necessarily quite as many black holes as we'd expect to see, if that was really always the case. So we thought, well, most of the time, then, there must be… I mean, most of the time, we're talking 60 00:08:25.580 --> 00:08:27.450 STFC-RAL-CR03 R61: Supernova, so it's not like we've got… 61 00:08:27.800 --> 00:08:34.190 STFC-RAL-CR03 R61: millions and millions of players, but most of the time, we see what we call a shockery viable. 62 00:08:34.620 --> 00:08:39.120 STFC-RAL-CR03 R61: And so, this is what we treated with become interesting. 63 00:08:39.980 --> 00:08:43.220 STFC-RAL-CR03 R61: People then thought that, 64 00:08:43.330 --> 00:08:49.530 STFC-RAL-CR03 R61: Well, we still think that this occurs through what we call a delayed neutrino heating mechanism. 65 00:08:50.150 --> 00:08:53.710 STFC-RAL-CR03 R61: So… What is that? 66 00:08:54.290 --> 00:08:57.690 STFC-RAL-CR03 R61: The idea is… your… 67 00:08:58.000 --> 00:09:08.760 STFC-RAL-CR03 R61: neutron star has to cool down, and essentially because there's a lot of energy from gravitation when you're actually making a neutron star. So. 68 00:09:09.150 --> 00:09:13.130 STFC-RAL-CR03 R61: The neutrino is probably the best way of getting energy out of there. 69 00:09:13.270 --> 00:09:27.450 STFC-RAL-CR03 R61: And the neutrinos then interact with, the free neutrons and protons that are there, so we have, some capture that occurs, heat up this, what we call this gain layer. 70 00:09:28.190 --> 00:09:41.569 STFC-RAL-CR03 R61: quite close to the core of the star, and the thinking is that this reheated gas eventually, is able to come in the shock, revive the shock, and essentially build supernova. So. 71 00:09:43.790 --> 00:09:47.009 STFC-RAL-CR03 R61: From an astrophysics point of view, sleep bye then. 72 00:09:47.400 --> 00:09:55.879 STFC-RAL-CR03 R61: my astrophysicist colleagues are happy, they're like, yeah, yeah, that's fine, and then I start talking to them about neutrinos. They fall asleep, because they're like, well. 73 00:09:56.320 --> 00:10:04.750 STFC-RAL-CR03 R61: whatever, you know, we know how it works. I'm like, well, actually, maybe we don't really know how this works, right? This is quite a dense… so, this is the thing, usually. 74 00:10:05.230 --> 00:10:19.260 STFC-RAL-CR03 R61: This is an extremely dense region, and we can imagine having strongly interacting neutrinos, so actually trying to understand what's happening in that strong interaction region is important for 75 00:10:19.260 --> 00:10:25.460 STFC-RAL-CR03 R61: One, all trying to understand fully the heating, but there's also other aspects of 76 00:10:25.460 --> 00:10:34.710 STFC-RAL-CR03 R61: The dynamics of what's happening in the explosions, whether similar explosions, if you don't include neutrinos or anything, you have usually some issues. 77 00:10:35.030 --> 00:10:44.370 STFC-RAL-CR03 R61: And it has also, ultimately, some implication on nuclear synthesis, and what sort of elements are produced when, 78 00:10:44.560 --> 00:10:47.739 STFC-RAL-CR03 R61: When stuff comes out of the supernote. 79 00:10:49.260 --> 00:10:50.149 STFC-RAL-CR03 R61: All right. 80 00:10:50.600 --> 00:10:56.990 STFC-RAL-CR03 R61: I will stop talking about astrophysics for a bit. Now, clearly, I had some slides on particle physics. 81 00:10:57.910 --> 00:11:04.679 STFC-RAL-CR03 R61: I'm gonna go through quite quickly, because I'm hoping most of you will not necessarily need to, 82 00:11:04.810 --> 00:11:14.709 STFC-RAL-CR03 R61: tell you what neutrinos are, but all the same, you know, I have one of my PhD students kindly prepare some neutrino slides, and it feels like I have to show them, because 83 00:11:14.810 --> 00:11:28.569 STFC-RAL-CR03 R61: They're quite nicely made, but we have some nice, nice, pictorial description of neutrinos. So, for people who don't know, neutrinos are in energy particles with remote charge, and a very small mass. 84 00:11:29.340 --> 00:11:36.170 STFC-RAL-CR03 R61: A very, very small mask. And, the… Exists in two distinct flavors. 85 00:11:36.450 --> 00:11:40.670 STFC-RAL-CR03 R61: So, the catch with neutrinos is that 86 00:11:41.920 --> 00:11:54.140 STFC-RAL-CR03 R61: We have detected those through their interaction with particles. We have not. So we name them after the interaction they came from. So we have electron neutrinos, neon neutrinos, and tau neutrinos. 87 00:11:55.600 --> 00:12:06.390 STFC-RAL-CR03 R61: But… these… Naming of neutrinos do not coincide with their mass eigenstones, which means that, in general. 88 00:12:07.070 --> 00:12:15.710 STFC-RAL-CR03 R61: we can't really say, oh, a nurturing neutrino has that much mass. It's a mixture of mass states, which, 89 00:12:15.950 --> 00:12:18.630 STFC-RAL-CR03 R61: is… Quite. 90 00:12:19.810 --> 00:12:25.469 STFC-RAL-CR03 R61: complex, I suppose. It's not super complex. We see there's three. The… 91 00:12:25.570 --> 00:12:38.210 STFC-RAL-CR03 R61: whether M1 is smaller than M2, which is smaller than M3, or whether it's the other way around, is not completely settled, although we tend to prefer M1 smaller than M2 smaller than M3. And… 92 00:12:39.500 --> 00:12:50.740 STFC-RAL-CR03 R61: Then the famous thing that we observe, so the thing that the interaction is happening with, is a superposition of mass eigenstates. This is essentially 93 00:12:51.520 --> 00:13:07.539 STFC-RAL-CR03 R61: I think for someone who's a quantum mechanics person, I'm just fine with this. I'm like, sure, just have a superposition of these states, and there's a unitary matrix that connects all of these. It's called the Q&S matrix, and 94 00:13:07.540 --> 00:13:12.029 STFC-RAL-CR03 R61: Everyone's busy measuring some of the elements of that matrix, but… 95 00:13:12.390 --> 00:13:19.409 STFC-RAL-CR03 R61: Overall, like, okay, so it's every particle is sort of a mixture of these three mass states. 96 00:13:22.620 --> 00:13:26.130 STFC-RAL-CR03 R61: That's the part I don't usually show to the astrophysicists, because 97 00:13:26.580 --> 00:13:34.740 STFC-RAL-CR03 R61: you remember by now the IC. The thing that wakes them up a little bit is this, because I say, well, okay, so why don't care? 98 00:13:34.860 --> 00:13:37.949 STFC-RAL-CR03 R61: Well, what actually matters is that 99 00:13:38.070 --> 00:13:47.530 STFC-RAL-CR03 R61: Imagine you produce a neutrino in specific flavors. Okay, for example, say it would take an electric neutrino, because this is actually what happens. 100 00:13:48.450 --> 00:13:55.439 STFC-RAL-CR03 R61: The astrophysicists know very well, called the solar eclrion, which is… you can actually calculate how many 101 00:13:56.230 --> 00:14:06.980 STFC-RAL-CR03 R61: electric neutrinos are being produced by, for example, old sun, and then when that got measured, suddenly there was a bit… we didn't get quite as many as we expected. And this is because 102 00:14:07.470 --> 00:14:16.740 STFC-RAL-CR03 R61: Since they don't have a definite mass, it's just a superposition of three mass states. As you travel, or as they travel through space. 103 00:14:17.280 --> 00:14:30.359 STFC-RAL-CR03 R61: they will oscillate, so the electric neutrino that we produce, and if you measure it later, for example, here at Earth, will be… could be detected as a muon or a tongue neutrino. 104 00:14:31.300 --> 00:14:35.810 STFC-RAL-CR03 R61: And the initial case could not be detected at all, because they have 105 00:14:36.430 --> 00:14:39.699 STFC-RAL-CR03 R61: I think in the original expense, there were only 106 00:14:40.220 --> 00:14:44.730 STFC-RAL-CR03 R61: detecting electric neutrinos, and… because they… they… 107 00:14:44.830 --> 00:14:51.210 STFC-RAL-CR03 R61: will be… well, they are the only ones that actually interact reasonably with matter. So. 108 00:14:53.320 --> 00:15:03.730 STFC-RAL-CR03 R61: That got people, usually, astrophysicists, are a little bit more interested in matrinos. I'm not saying they're not interested, it's just that they have other stuff that they're particularly interested in. 109 00:15:03.960 --> 00:15:05.310 STFC-RAL-CR03 R61: So, 110 00:15:07.340 --> 00:15:13.569 STFC-RAL-CR03 R61: We want to simulate this, we want to understand neutrinos just a bit more, so we can do things like, 111 00:15:14.390 --> 00:15:19.270 STFC-RAL-CR03 R61: Oscillations, so these are… this is some of the 112 00:15:19.680 --> 00:15:30.180 STFC-RAL-CR03 R61: Early examples of what we did a little while back on using quantum computers to simulate neutrino simulations. 113 00:15:30.640 --> 00:15:45.880 STFC-RAL-CR03 R61: I will talk to you a little bit more about this, but I just wanted to show you that this is typically a sort of oscillation profile that we have. We are all, you know, weird neutrino units of length divided by energy. 114 00:15:46.040 --> 00:15:59.720 STFC-RAL-CR03 R61: Because most of your part of this is true. You'll be all down with that, this is fine. And here, this is looking at what we call the survival probability, so this is the probability of, 115 00:16:00.280 --> 00:16:15.440 STFC-RAL-CR03 R61: the… essentially, the neutrino is still staying what it… staying as it is, so if we start initially with an electric neutrino, it also changes flavor and then comes back up, again, as an electric neutrino a little bit later on. 116 00:16:15.990 --> 00:16:18.580 STFC-RAL-CR03 R61: And then we have similar profiles for 117 00:16:18.660 --> 00:16:34.630 STFC-RAL-CR03 R61: neons and tauves. What excited us reasonably well at the time is the dots that we see is what was simulated using, one of the, quantum computers that the NQCC put at our disposal, and 118 00:16:34.630 --> 00:16:45.710 STFC-RAL-CR03 R61: we're like, okay, this is, this is fine, this is roughly okay. We, we broadly reproduce what happens, and it seems to follow 119 00:16:45.720 --> 00:16:47.429 STFC-RAL-CR03 R61: theory reasonably well. 120 00:16:48.350 --> 00:17:05.180 STFC-RAL-CR03 R61: So then we thought, let's be bold. This is just a neutrino in vacuum, a single neutrino in vacuum. Maybe we can do better than this. So then we went through to adding some matter oxidate, so matter potential, so this was 121 00:17:05.260 --> 00:17:14.440 STFC-RAL-CR03 R61: what we call a Wolfenstein potential, which essentially simulates how Electron neutrinos interact with matter. 122 00:17:14.579 --> 00:17:21.350 STFC-RAL-CR03 R61: It doesn't have interactions for the real model channel, and what we'll see 123 00:17:21.980 --> 00:17:31.070 STFC-RAL-CR03 R61: is, sort of what we'd expect. We have the top panelists, the Electron 124 00:17:31.430 --> 00:17:43.580 STFC-RAL-CR03 R61: channel, so we're looking at a single mule neutrino that is now left to its own device, and propagate there. And as we increase the strength of 125 00:17:43.630 --> 00:17:52.700 STFC-RAL-CR03 R61: The matter interaction, we see that our survival probability just goes down and down and down, while the, 126 00:17:53.140 --> 00:18:01.860 STFC-RAL-CR03 R61: where the other channels, Neon and TAF, are getting a little bit… increased, 127 00:18:02.400 --> 00:18:18.680 STFC-RAL-CR03 R61: we're happy with this. I mean, this sort of works reasonably well. This was also a test of the quantum computing simulations, and they… they are pretty much close to what we'd expect for the analytical results. Now. 128 00:18:19.540 --> 00:18:20.580 STFC-RAL-CR03 R61: Clearly. 129 00:18:22.680 --> 00:18:30.160 STFC-RAL-CR03 R61: This is just a single neutrina. We have analytical solutions for this, we don't need to be a multi-computer for that. 130 00:18:30.480 --> 00:18:37.400 STFC-RAL-CR03 R61: So, why do we do this? Well, the idea is, first, we wanted to test, whether it actually, 131 00:18:38.580 --> 00:18:50.819 STFC-RAL-CR03 R61: of where it actually works, because this is meant to be a reasonable problem to run on a quantum computer. But what we wanted to do, ultimately, is try and see whether, if we start adding more and more. 132 00:18:50.820 --> 00:18:56.390 STFC-RAL-CR03 R61: neutrinos, maybe this gives us a simpler formalism to actually 133 00:18:56.390 --> 00:19:12.719 STFC-RAL-CR03 R61: look at interactions at… or quantum interaction at the larger scale. Remember, what we want to do is try and understand what happens when we have loads and loads of neutrinos, ideally near a star, or inside an exploding star, and try and understand what's going to 134 00:19:13.430 --> 00:19:18.350 STFC-RAL-CR03 R61: So we started looking at introductions, so… 135 00:19:18.470 --> 00:19:33.910 STFC-RAL-CR03 R61: Traditionally, neutrinos don't really interact very much with each other. It's a bit like, sometimes when I talk to people who do photonic quantum computers, I think it's a bit, and sometimes, you know, when you try and entangle them, it's a bit harder, but, 136 00:19:34.350 --> 00:19:43.259 STFC-RAL-CR03 R61: The idea is here, because we're in a dense medium inside a coarse collapse supernova, we think there's definitely a good, 137 00:19:43.620 --> 00:20:00.799 STFC-RAL-CR03 R61: good chance that they will likely interact, because they are all quite tightly close to each other. From a particle physics point of view, we'll parameterize those, using some sort of forward sketching process, which is what we call refraction processes. 138 00:20:01.240 --> 00:20:09.180 STFC-RAL-CR03 R61: Where you have, Essentially, Things are either, leave your 139 00:20:09.290 --> 00:20:15.639 STFC-RAL-CR03 R61: Your neutrinos, stuff, and change with… with respect to that. 140 00:20:16.240 --> 00:20:24.440 STFC-RAL-CR03 R61: We're ensuring the final momenta, or you have a sort of exchange scattering normally, exchange momentum from particles. 141 00:20:24.980 --> 00:20:27.700 STFC-RAL-CR03 R61: And it's so reasonably well documented. 142 00:20:28.090 --> 00:20:45.449 STFC-RAL-CR03 R61: This is a paper from 95 or so, but there's plenty of literature on people looking at how we can look at neutrino-neutrino interactions. In our case, we're interested both in the neutrino and anti-neutrino sectors, so we're going to part all of those together. 143 00:20:47.730 --> 00:20:53.839 STFC-RAL-CR03 R61: But we still wanted to put all of that on a quantum computer, because we thought, hmm, yeah, maybe… 144 00:20:53.950 --> 00:21:01.150 STFC-RAL-CR03 R61: a very, very large collective regime, might be an interesting, case study for Xi. 145 00:21:01.680 --> 00:21:12.180 STFC-RAL-CR03 R61: So… What we did is use… use what we call a simplified collecting tumor model. 146 00:21:13.880 --> 00:21:20.889 STFC-RAL-CR03 R61: We decided, even though there are 3 flavors, we only use 2 to make things easier. To be honest. 147 00:21:21.520 --> 00:21:24.109 STFC-RAL-CR03 R61: Most of the interesting things happens. 148 00:21:25.270 --> 00:21:30.890 STFC-RAL-CR03 R61: The electron neutrinals, because they're the ones that interact the most with matter, so 149 00:21:31.650 --> 00:21:38.690 STFC-RAL-CR03 R61: will, keep those. In particular, also, they're the ones that seem to participate more, readily in all of them. 150 00:21:39.310 --> 00:21:41.039 STFC-RAL-CR03 R61: Reactions that we've seen. 151 00:21:41.250 --> 00:21:46.169 STFC-RAL-CR03 R61: And then we'll just have, like, electrone neutrino and other. 152 00:21:46.630 --> 00:21:49.029 STFC-RAL-CR03 R61: You're shooting out X. 153 00:21:49.690 --> 00:22:02.340 STFC-RAL-CR03 R61: And we'll be okay. So it's a… it's a two-state model, which would make the math this a bit simpler. And then, in that case, if we do it this way, we have two mass, 154 00:22:03.130 --> 00:22:21.569 STFC-RAL-CR03 R61: mass channels, that we call mass 1 and mass 2, and we use what we call the vacuum mixing angle, which will correspond to, I think this is electron mixing angle. It's an approximation, but the idea is we want to go for 155 00:22:22.000 --> 00:22:26.619 STFC-RAL-CR03 R61: For a large collection of neutrinos, and we can always make it harder afterwards. 156 00:22:28.050 --> 00:22:36.350 STFC-RAL-CR03 R61: We're also going to change a little bit, and we're going to ignore initially the, 157 00:22:36.800 --> 00:22:51.420 STFC-RAL-CR03 R61: matter interaction. We put it back up towards lithium, but initially we thought we'll just have a standard vacuum propagation, and then what we're interested in is adding this interaction between the treatments. 158 00:22:52.610 --> 00:23:00.400 STFC-RAL-CR03 R61: So… There's actually quite a convenient way of writing this using Whoa. 159 00:23:00.950 --> 00:23:04.170 STFC-RAL-CR03 R61: People call flavor isosphere notation. 160 00:23:05.120 --> 00:23:24.299 STFC-RAL-CR03 R61: Mainly, this becomes clearer later when we look at how this maps to a quantum computer, but it enables us to look at a set of spin operators, so we have one terms that looks after the vacuum oscillations. 161 00:23:24.840 --> 00:23:30.370 STFC-RAL-CR03 R61: So we have a mass spectra, direction that looks at. 162 00:23:30.680 --> 00:23:37.470 STFC-RAL-CR03 R61: The mass trajectories, and then we're looking at how the isospin is, parallel or perpendicular. 163 00:23:37.610 --> 00:23:40.009 STFC-RAL-CR03 R61: conduct a mass direction. 164 00:23:40.520 --> 00:23:48.960 STFC-RAL-CR03 R61: And then the slightly more interesting part when we talk about interactions is essentially how two neutrinos 165 00:23:49.180 --> 00:23:55.169 STFC-RAL-CR03 R61: momentum, or isos, isosphere might couple to each other, and 166 00:23:55.990 --> 00:23:58.779 STFC-RAL-CR03 R61: Here we have a coupling constant. 167 00:23:59.340 --> 00:24:12.840 STFC-RAL-CR03 R61: and a sort of cosine-dependent strength, which will sort of help us tell whether your neutrinos are sort of collinear, or whether they are deviating a little bit. We'll see when we, 168 00:24:13.400 --> 00:24:27.669 STFC-RAL-CR03 R61: And I streamline the model in about a minute, that the assumption is that the neutrinos will sort of radiate out, so that they sort of come out with a slightly different angle. I've got them here. 169 00:24:28.900 --> 00:24:30.509 STFC-RAL-CR03 R61: So, 170 00:24:30.650 --> 00:24:50.139 STFC-RAL-CR03 R61: If we imagine the core of our star here, and, so there's what we call the neutrino sphere, which is… which sort of starts a little bit before the… or finishes a little bit before this, almost look up from 60 kilometers from the center to about 250 kilometers. 171 00:24:50.540 --> 00:25:01.919 STFC-RAL-CR03 R61: And the idea is the neutrinos would stream out like this, and they… they can, you don't have to, but they can have, like, a slight different, slightly different solid angle between them, so we've had 172 00:25:02.070 --> 00:25:08.249 STFC-RAL-CR03 R61: To the neutrinos, and, And we'll write it like that. Now. 173 00:25:09.190 --> 00:25:15.720 STFC-RAL-CR03 R61: If we look at what the Hamilton looks like, And… We… I don't… 174 00:25:16.320 --> 00:25:20.850 STFC-RAL-CR03 R61: built on, I suppose, a… a hat of, 175 00:25:21.010 --> 00:25:27.880 STFC-RAL-CR03 R61: say, condensed matter physicists for a minute. This actually looks like 176 00:25:28.720 --> 00:25:39.910 STFC-RAL-CR03 R61: sort of an async time model, or a Heisenberg-type model. It looks like a model where we would have a set of magnetic spins, so if I was to write 177 00:25:40.610 --> 00:25:47.390 STFC-RAL-CR03 R61: magnetic Hamiltonians, It would look very much like a state, the 178 00:25:47.710 --> 00:25:53.729 STFC-RAL-CR03 R61: constant, or the strength is slightly different, but that's roughly what it looks like, which 179 00:25:54.050 --> 00:26:06.340 STFC-RAL-CR03 R61: is actually going to be quite good news for us, because the quantum computing people spend quite a lot of time solving, magnetic phase transition, this kind of thing, so a lot of the tools are already there. 180 00:26:07.530 --> 00:26:13.769 STFC-RAL-CR03 R61: We're going to assume that the coupling strength isotropic for us, that we don't have any problems. 181 00:26:14.900 --> 00:26:28.990 STFC-RAL-CR03 R61: The neutrinos now are emitted, and essentially they will… they will travel quite far and fast, and they will drift apart, so we'll simulate this by changing the coupling strength, because we… they're going further and further away. 182 00:26:29.160 --> 00:26:46.349 STFC-RAL-CR03 R61: We're interested in having a model where we can look at, essentially, some gravity influence from there. We're quite close to quite a massive object. It might even be from a black hole at some stage. What are the effects on some of the, some of the parameters? 183 00:26:47.080 --> 00:27:02.040 STFC-RAL-CR03 R61: And clearly, there's many, many ways of doing it. So people have been doing this for a while. You have, two sort of types of approximations that people are doing. There's what we call a single angle approximation, where you have two, like, all the 184 00:27:03.000 --> 00:27:11.830 STFC-RAL-CR03 R61: All your neutrinos, coming up whole linearly, senior competing. 185 00:27:12.350 --> 00:27:18.559 STFC-RAL-CR03 R61: And then you have something that looks a bit like a… I suppose in… in… 186 00:27:21.220 --> 00:27:30.189 STFC-RAL-CR03 R61: The electronic structure, we call it a random phase approximation, to some extent, where you sort of more or less trying to 187 00:27:32.000 --> 00:27:38.309 STFC-RAL-CR03 R61: Write out your, your expectation values of, of your, 188 00:27:38.700 --> 00:27:53.190 STFC-RAL-CR03 R61: dot product as a product of the expectation value, so essentially trying to trace out a set of degrees of freedom, and you have an effective potential. This is sort of a mean field engineering of sorts. 189 00:27:54.270 --> 00:28:08.870 STFC-RAL-CR03 R61: They both work, but I think the question that we're trying to pursue is to say, well, sure, they might work, but what are we neglecting? What effects are maybe not there when we look at the mean field rather than instantaneous interactions? 190 00:28:10.180 --> 00:28:11.200 STFC-RAL-CR03 R61: All right. 191 00:28:13.150 --> 00:28:15.560 STFC-RAL-CR03 R61: Only a quantum computing experience. 192 00:28:16.600 --> 00:28:19.209 STFC-RAL-CR03 R61: Not many. Okay, that's good, that's good. 193 00:28:19.770 --> 00:28:23.779 STFC-RAL-CR03 R61: So I have a couple of slides to explain, 194 00:28:24.010 --> 00:28:28.039 STFC-RAL-CR03 R61: quantum computing. So, the idea? Yeah. 195 00:28:28.260 --> 00:28:31.999 STFC-RAL-CR03 R61: As you could very rightly ask yourself, walnuts… 196 00:28:33.610 --> 00:28:48.120 STFC-RAL-CR03 R61: But we just have perfectly fine computers? We do! We have very good computers. I spent ages programming normal computers for probably most of my time. But, the idea here is 197 00:28:49.040 --> 00:29:02.339 STFC-RAL-CR03 R61: Quantum computing could give us just slightly different pathways of doing things. The idea there is, if we can map our system, we essentially don't have to calculate it, we just have to observe it. So it's a bit like… 198 00:29:02.950 --> 00:29:07.680 STFC-RAL-CR03 R61: Constructing an experiment that happens to solve the problem that we're looking at. 199 00:29:08.280 --> 00:29:12.749 STFC-RAL-CR03 R61: So, how does that work? Instead of having 200 00:29:13.160 --> 00:29:16.600 STFC-RAL-CR03 R61: Normal bits, like the rules 0 and 1, we have. 201 00:29:16.940 --> 00:29:33.120 STFC-RAL-CR03 R61: two bits that have stage 0, state 1, and typically people represent this on this block sphere here, so the idea would be if you want state 0, you're at the top, if you're at stage 1 at the bottom, but because this is 202 00:29:33.280 --> 00:29:42.130 STFC-RAL-CR03 R61: auto mechanics, The coefficients that you have can be complex numbers, and that also means that you can make 203 00:29:42.230 --> 00:29:57.219 STFC-RAL-CR03 R61: essentially combinations of zeros and ones. So, if you want to simplify that to be extreme, it's like saying, instead of being just on and off, you could be anywhere between on and off on a complex way. 204 00:29:59.610 --> 00:30:03.480 STFC-RAL-CR03 R61: We need, like we do on a normal computer, to be able to 205 00:30:03.680 --> 00:30:13.339 STFC-RAL-CR03 R61: perform operations on this… on this quantum base. This is usually, done using unitary rotations. You can rotate these. 206 00:30:13.840 --> 00:30:24.369 STFC-RAL-CR03 R61: And these end up being, SU cube body matrices, so we can make superpositions. There's also a whole set of, 207 00:30:25.040 --> 00:30:32.220 STFC-RAL-CR03 R61: Of operations that enable us to look at multiple qubits, so essentially how we go from 208 00:30:32.920 --> 00:30:40.580 STFC-RAL-CR03 R61: a 1, 2, 3, 4, 5, at the minute. Some of the You need to get… 209 00:30:40.820 --> 00:30:48.909 STFC-RAL-CR03 R61: Probably up to, reasonably, 200 and, also on atom-based, 210 00:30:49.070 --> 00:30:55.419 STFC-RAL-CR03 R61: Onto the computer. The ones we've been using are around 100, 120. 211 00:30:55.620 --> 00:31:06.929 STFC-RAL-CR03 R61: qubits, so we have also gates that enable us to, to control what happens, and this, lets us make non-classical states, or entangled states. 212 00:31:07.370 --> 00:31:12.929 STFC-RAL-CR03 R61: This is where we have, essentially, where we say, oh, if this qubit does this, you do that with the other one tech. 213 00:31:13.100 --> 00:31:19.510 STFC-RAL-CR03 R61: So we can generate an algorithm with those, very much the same as we can generate an algorithm on a normal. 214 00:31:19.750 --> 00:31:27.909 STFC-RAL-CR03 R61: a classical computer. Of course, it sort of… when you're doing it that way, it brings us back to… 215 00:31:30.150 --> 00:31:46.170 STFC-RAL-CR03 R61: a bit more like the very early days of computing, where really you end up having to, you know, you specify your circuit, and it does things that way. It's sometimes really close to, sort of, how you might do it with, sort of, actual electronics. 216 00:31:47.690 --> 00:31:52.569 STFC-RAL-CR03 R61: But, despite of all this great 217 00:31:52.710 --> 00:31:57.390 STFC-RAL-CR03 R61: quantum things that you can do on these quantum operations. Ultimately. 218 00:31:57.510 --> 00:32:10.079 STFC-RAL-CR03 R61: You still have to get the results… you still have to get some classical results out, because the normal computer value interface is not classical, so you measure your qubit, and in the end, you just get 0 or 1. 219 00:32:11.090 --> 00:32:19.760 STFC-RAL-CR03 R61: And… the only advantage or disadvantage, I mean, the advantage is you can sort of 220 00:32:20.880 --> 00:32:30.419 STFC-RAL-CR03 R61: Tailor what sort of results you're going to get, because it comes with a, it comes out with a probability that's proportional to the coefficients that you've put in. 221 00:32:30.730 --> 00:32:43.759 STFC-RAL-CR03 R61: But that's also the disadvantage, because you don't really get a different answer, you just get a probabilistic answer to what the result is. So usually, typically, we will run these experiments many times. 222 00:32:44.100 --> 00:32:58.760 STFC-RAL-CR03 R61: And this is a simple experiment that I've worked out for you. These are real results from one of the machines, where I was, I think, trying to get it to measure, sort of, mixed 223 00:32:58.760 --> 00:33:10.169 STFC-RAL-CR03 R61: entangled state. I was… I'm not a particularly lucky person in general, as well, so I was expecting a sort of 50-50 thing. It didn't quite work out that way, so it would… 224 00:33:10.170 --> 00:33:18.719 STFC-RAL-CR03 R61: we've got, sort of, this one is 0, 1, and 1, 0, so you end up with something. I always see that when we do measurements for capsule. 225 00:33:18.720 --> 00:33:30.219 STFC-RAL-CR03 R61: Some little fringes here. But, you know, by and large, you could sort of work out that, okay, it's doing things, it's got qubits, you can make things, and it sort of does what you want. 226 00:33:31.380 --> 00:33:33.559 STFC-RAL-CR03 R61: Right? So I was like, oh, this is good. 227 00:33:34.470 --> 00:33:36.510 STFC-RAL-CR03 R61: Let's map. So… 228 00:33:39.440 --> 00:33:47.560 STFC-RAL-CR03 R61: we only have two states. That works quite well, so we can map our flavors, we can say, okay, electron. 229 00:33:47.720 --> 00:33:51.639 STFC-RAL-CR03 R61: Neutrino is going to be zero, state zero, 230 00:33:52.210 --> 00:33:54.859 STFC-RAL-CR03 R61: Although, neutrino will be state 1. 231 00:33:55.470 --> 00:33:58.670 STFC-RAL-CR03 R61: The ISO Spins operator 232 00:33:58.780 --> 00:34:10.289 STFC-RAL-CR03 R61: also align with SC2-type algebra, so I was like, oh, this is like a polymatrix, so we can use polymatrices now to act as our isospin operators. 233 00:34:11.070 --> 00:34:25.180 STFC-RAL-CR03 R61: And because we have an isotropic interaction, this is actually what we call an XXX Heisenberg model, where everything is isotropic in all directions. 234 00:34:25.739 --> 00:34:33.009 STFC-RAL-CR03 R61: So we can essentially rewrite or equation in terms of 235 00:34:33.340 --> 00:34:46.739 STFC-RAL-CR03 R61: a poly matrix here, and some X matrices. And here, there's a couple of, sorry, X, Y, and Z polymatrices, so that… this part implements the Heisenberg model, and this is doing the vacuum. 236 00:34:47.679 --> 00:34:56.099 STFC-RAL-CR03 R61: There's a couple of factors that creep up just because of the way these particular polymatrix are implemented on the quantum computer. 237 00:34:56.270 --> 00:35:02.450 STFC-RAL-CR03 R61: But, basically, all we need to do then, we set up the figures that we want, We'll say. 238 00:35:02.970 --> 00:35:05.569 STFC-RAL-CR03 R61: quantum computer, he's a Hamiltonian. 239 00:35:06.300 --> 00:35:15.980 STFC-RAL-CR03 R61: please do the thing properly. And so we can evolve, then, the state from, sort of, the end of the neutrinosphere 240 00:35:16.580 --> 00:35:19.389 STFC-RAL-CR03 R61: Inside the game like an apostle creature. 241 00:35:20.240 --> 00:35:23.559 STFC-RAL-CR03 R61: So, in practical terms, this is my… 242 00:35:24.160 --> 00:35:30.110 STFC-RAL-CR03 R61: Last slide on, on, on team computing, so we… This is theory, this is… 243 00:35:30.290 --> 00:35:35.520 STFC-RAL-CR03 R61: Essentially, what we do, we have states, we have… we apply Hamiltonian. 244 00:35:36.270 --> 00:35:42.180 STFC-RAL-CR03 R61: We have to essentially discretize this, to make it, 245 00:35:43.170 --> 00:35:55.619 STFC-RAL-CR03 R61: computable, because most of those, there's rotation relations, etc, so we end up having to make extra small steps. So we ended up sort of splitting things into half steps. 246 00:35:55.740 --> 00:36:02.290 STFC-RAL-CR03 R61: It turned out that instead of using time, it was probably easier to use radial steps, but that's sort of the same thing. 247 00:36:02.480 --> 00:36:08.600 STFC-RAL-CR03 R61: I think the interesting thing is we end up with, essentially, a circuit, which is how we 248 00:36:08.710 --> 00:36:13.850 STFC-RAL-CR03 R61: programmed onto the computer. That is reasonably simple in the sense that we have 249 00:36:14.360 --> 00:36:27.589 STFC-RAL-CR03 R61: Flavor to mass at the start, transformation and mass to flavor transformation at the end, and then in the middle, we will just, do path back, or interaction, path back, and that… 250 00:36:29.580 --> 00:36:45.619 STFC-RAL-CR03 R61: yellowish bit is what moves the wave function forward. So we do… if you're on the first time step, you just do it once. If you're on the second time step, you do it twice, and then et cetera, et cetera. So you sort of repeat this as many times as you want, and by the end, you have repeated it 251 00:36:46.610 --> 00:36:53.150 STFC-RAL-CR03 R61: 40 times, 50 times, whatever many times you want, and you start then from the end, and it just carries you all the way. 252 00:36:53.710 --> 00:36:55.300 STFC-RAL-CR03 R61: to the F. 253 00:36:56.060 --> 00:37:01.240 STFC-RAL-CR03 R61: The aim was to do about 100 neutrinos or qubits model. 254 00:37:01.360 --> 00:37:11.150 STFC-RAL-CR03 R61: I'll put that out there, because now I'm going to show you some results. We'll be able to reflect on whether that is a realistic goal in this particular building. 255 00:37:11.410 --> 00:37:21.540 STFC-RAL-CR03 R61: So… Well, okay, let's… let's be exciting. Let's… let's start test things. So, we… 256 00:37:21.870 --> 00:37:38.989 STFC-RAL-CR03 R61: starting with putting no interactions into things. This is the vacuum propagation, it should be the same sort of code that we have before. I'm starting with just two neutrinos, a neutrino and a neutrino, so I've got two sectors here, neutrino sector and neutrino sector. 257 00:37:39.590 --> 00:37:40.530 STFC-RAL-CR03 R61: And… 258 00:37:40.740 --> 00:37:54.860 STFC-RAL-CR03 R61: We're just looking at oscillations and how they are reproduced compared to the analytical. This looks really good, because this is a simulation of the quantit function. So, very, very long time ago, when I started doing this, people said, oh. 259 00:37:55.670 --> 00:37:58.610 STFC-RAL-CR03 R61: Always start with simulation, because 260 00:37:58.770 --> 00:38:06.850 STFC-RAL-CR03 R61: you, you know, you need a simulation. You need a simulation. So we need a simulation, so this works quite well. 261 00:38:07.250 --> 00:38:10.600 STFC-RAL-CR03 R61: And we're like, okay, does it work when we… 262 00:38:10.720 --> 00:38:20.899 STFC-RAL-CR03 R61: Add, some interactions. When we start to put the interaction, we see things are starting to get a little bit dampened, and it's, we see there's a bit of structure there, but… 263 00:38:20.900 --> 00:38:34.220 STFC-RAL-CR03 R61: It seems to work, it's okay. We use adaptive steps, because the idea is we have stronger oscillations at the start, we have at the end, so we don't need maybe as many 5 steps towards the end. This is working well. 264 00:38:35.830 --> 00:38:45.800 STFC-RAL-CR03 R61: We then also started looking at simulating, sort of, a 3 plus 3 system, so here we have, we have… 265 00:38:46.230 --> 00:38:53.289 STFC-RAL-CR03 R61: A set of three different energies for initial neutrinos, and what we start seeing 266 00:38:53.680 --> 00:39:03.750 STFC-RAL-CR03 R61: I wanted to compare this with the, single angle approximation to nuclear approximation of infields of split things, so low electric energy. 267 00:39:03.870 --> 00:39:08.990 STFC-RAL-CR03 R61: keep their flavor. High-age neutrinos tend to 268 00:39:09.200 --> 00:39:12.650 STFC-RAL-CR03 R61: lose their flavors. We have a sort of… 269 00:39:13.620 --> 00:39:19.860 STFC-RAL-CR03 R61: There's separation given, and you see that the quantum part sort of follows it, roughly. 270 00:39:20.170 --> 00:39:27.809 STFC-RAL-CR03 R61: And that seems to happen on both, on both sectors. Seems to be dampened quite a bit. 271 00:39:28.400 --> 00:39:36.420 STFC-RAL-CR03 R61: But if we actually move to, a multiple angle model, so… which is close to what we're simulating in our… 272 00:39:36.550 --> 00:39:40.959 STFC-RAL-CR03 R61: In our model, we've got a little bit less spitting, and 273 00:39:41.210 --> 00:39:44.120 STFC-RAL-CR03 R61: Roughly, you know, if you scroll it. 274 00:39:44.400 --> 00:39:47.870 STFC-RAL-CR03 R61: You go, yeah, yeah, okay, it sultan works. 275 00:39:48.710 --> 00:39:50.829 STFC-RAL-CR03 R61: So, it's reasonable. 276 00:39:52.990 --> 00:40:01.220 STFC-RAL-CR03 R61: And bolded by this, we thought, we'll now go on the real machine and see how whether we can actually reproduce the squiggles, whether it's squiggles. 277 00:40:02.470 --> 00:40:17.190 STFC-RAL-CR03 R61: Oh, okay. So, here's a real machine, you'll start paying to pay some real money now. So, it's not my money, it's the NQCC's money, but all the same, you know, we're mindful. So, I'm going to do only 20 times, 20 steps. 278 00:40:17.190 --> 00:40:35.089 STFC-RAL-CR03 R61: Because I know roughly what's happening, so I'm going to undersample some of the oscillations, so sometimes when there's things like that, because we know that underneath there's probably quite a few oscillations underneath, but I wanted to see, roughly… I'm interested to see whether I see that phase separation. I'm not going to have phase separation with a 1 plus 1 system. 279 00:40:35.100 --> 00:40:46.179 STFC-RAL-CR03 R61: But this was the serination at the top, right? This is the real machine at the bottom, and I was like, oh my goodness, mate, this is really good, this is close, this is really close! Oh! 280 00:40:46.770 --> 00:40:49.119 STFC-RAL-CR03 R61: So good. I felt really happy. 281 00:40:51.190 --> 00:40:52.030 STFC-RAL-CR03 R61: No, no. 282 00:40:52.330 --> 00:40:58.709 STFC-RAL-CR03 R61: added more neutrinos, so I have my simulation at the top, and then I'm like, oh… 283 00:40:58.880 --> 00:41:04.260 STFC-RAL-CR03 R61: what is happening here. This is the real calculation, so I started to be a bit too… 284 00:41:04.660 --> 00:41:08.259 STFC-RAL-CR03 R61: Okay, not quite what I expected, but alright. 285 00:41:08.410 --> 00:41:10.259 STFC-RAL-CR03 R61: Maybe it's just too frustrating. 286 00:41:10.420 --> 00:41:11.469 STFC-RAL-CR03 R61: Who knows? 287 00:41:12.360 --> 00:41:13.620 STFC-RAL-CR03 R61: Just a few more. 288 00:41:14.510 --> 00:41:19.850 STFC-RAL-CR03 R61: Things in there. Simulation, fantastic. Read machine, blah. 289 00:41:20.820 --> 00:41:24.160 STFC-RAL-CR03 R61: Yeah. I mean, you know, if I'm being… 290 00:41:24.370 --> 00:41:33.819 STFC-RAL-CR03 R61: you know, super optimistic. Not the right ones, but it's also followed some of the curve. 291 00:41:34.050 --> 00:41:34.910 STFC-RAL-CR03 R61: So… 292 00:41:38.370 --> 00:41:56.089 STFC-RAL-CR03 R61: what sort of is going on? This was my… my thinking was taking the bus to come here, depending on which side was that. The simulation worked really well. It was really good. It looked super promising. And now I've run it on a real machine. 293 00:41:57.630 --> 00:42:01.470 STFC-RAL-CR03 R61: And it's a little bit bleaker than Whittle. I mean. 294 00:42:02.560 --> 00:42:15.540 STFC-RAL-CR03 R61: We know this, to some extent, right? It's like, whenever you do something experimentally, you have some measurement errors, etc, etc. I think here there's a couple of things that happen, the simulation. 295 00:42:15.660 --> 00:42:19.520 STFC-RAL-CR03 R61: Are not really taking much 296 00:42:20.390 --> 00:42:34.910 STFC-RAL-CR03 R61: much of the actual video here, so simulations are a bit too, ideal, if you wish. Yep. You're using this QScript for simulation? Yes, yes, yes. There you are also loading the… 297 00:42:35.260 --> 00:42:50.440 STFC-RAL-CR03 R61: there's something called machine dynamics, something like that. Yeah, so you can, you can load, you could take into account the parameters from the machine, etc, to try and make the simulation even more realistic. But, ultimately. 298 00:42:51.910 --> 00:43:00.559 STFC-RAL-CR03 R61: the way this works is when I make all these many, many steps, I probably hit what we call, 299 00:43:00.560 --> 00:43:14.769 STFC-RAL-CR03 R61: some of the issues with, essentially, the survival of these qubits. So they sort of eco here, and by the time, in fact, most of the curve ended up roughly around halfway, which is what you'd expect if you put things that were a little bit done. 300 00:43:17.040 --> 00:43:21.870 STFC-RAL-CR03 R61: You know, we don't… I'm not panicking quite yet, because… 301 00:43:24.570 --> 00:43:30.040 STFC-RAL-CR03 R61: The two-level model actually fits quite well for quantum computer. 302 00:43:31.080 --> 00:43:33.180 STFC-RAL-CR03 R61: In simulations, they both 303 00:43:33.400 --> 00:43:46.150 STFC-RAL-CR03 R61: Show, sort of, this onset of face transition, like this splitting that we may be looking for, just because it's interesting, and it's more of a mark of, sort of, these, 304 00:43:47.550 --> 00:43:50.550 STFC-RAL-CR03 R61: We sort of condensed… system. 305 00:43:53.640 --> 00:44:07.310 STFC-RAL-CR03 R61: running on… or running on Vienna hardware, actually is really not what we need in order to be able to develop better versions of this. So, now, the plan is 306 00:44:08.050 --> 00:44:14.069 STFC-RAL-CR03 R61: We know how to fix this, but we're only about one month into this project, so… 307 00:44:14.220 --> 00:44:23.120 STFC-RAL-CR03 R61: there's a bit of time left. I have a very good idea of how to fix this, but I wanted to first, you know, first you start simple, and you go, okay, how… 308 00:44:23.230 --> 00:44:27.060 STFC-RAL-CR03 R61: How well, you know, will… will this work? And… 309 00:44:27.580 --> 00:44:32.570 STFC-RAL-CR03 R61: It's interesting that even though hardware has come on quite a bit, you can't just 310 00:44:33.020 --> 00:44:38.100 STFC-RAL-CR03 R61: You know, you have to still be quite careful into how you program these computers. 311 00:44:38.760 --> 00:44:44.319 STFC-RAL-CR03 R61: I've sort of popped them just on time, and I'll finish with this. 312 00:44:44.440 --> 00:44:48.030 STFC-RAL-CR03 R61: Also, a huge thank you to NQCC. 313 00:44:48.230 --> 00:44:58.089 STFC-RAL-CR03 R61: that have been very patient with us and gave us lots of computing time, and, or HPC at home as well, and… 314 00:44:59.290 --> 00:45:02.640 STFC-RAL-CR03 R61: Thank you. 315 00:45:07.870 --> 00:45:12.479 STFC-RAL-CR03 R61: I think I have about 100 questions. Okay. Let everybody run fast first, so please… 316 00:45:15.130 --> 00:45:31.269 STFC-RAL-CR03 R61: Can I go back to the beginning? It's probably implicit in everything you're talking about, but you didn't… you didn't mention the early exclusion principle, and that's what's stopping the star… That's right. Does it back pressure on the neutrinos? I think, so what happens is it's usually 317 00:45:31.420 --> 00:45:43.890 STFC-RAL-CR03 R61: It stops the collapse, but then they get… you get to a point where they get sort of reabsorbed into this neutronization phase, where the electrons that usually would keep 318 00:45:44.290 --> 00:45:54.019 STFC-RAL-CR03 R61: Keep the core from the collapses get reabsorbed into the nuclei, and they essentially lose the most powerful there, and then they continue to get there. 319 00:45:54.620 --> 00:46:00.829 STFC-RAL-CR03 R61: But I was worried about the neutrino emission being held up, because foreign states… Oh, okay, yeah, so… 320 00:46:01.330 --> 00:46:05.009 STFC-RAL-CR03 R61: What happens is, when you have quite a lot of 321 00:46:06.930 --> 00:46:16.530 STFC-RAL-CR03 R61: quite a lot of electrons and masses, so yes, it does block some of the neutrino emission, because it's sort of quite opaque in the initial stages, but by the time you reach 322 00:46:16.570 --> 00:46:35.359 STFC-RAL-CR03 R61: the, sort of, end phase, which is where you're making your neutron star, this becomes much less focused to neutrinos, so you suddenly have streams. These are the, sort of, neutrino streams that we can see, sort of, from outside. They come more for what we call the late stage. 323 00:46:37.870 --> 00:46:47.190 STFC-RAL-CR03 R61: total neutron star type station, the ocean. You're right, at the early stages, when you have all these neutrino emissions, they… they… 324 00:46:47.720 --> 00:46:52.100 STFC-RAL-CR03 R61: are a bit trucked in the show, 325 00:46:55.030 --> 00:46:56.800 STFC-RAL-CR03 R61: regulators as well. 326 00:46:56.800 --> 00:47:19.389 STFC-RAL-CR03 R61: Isn't it the case that, I mean, you've got inverse beta decay happening in the core, and what's happening is you're releasing neutrinos during the protonutron phase, and what happens is you've got some multiple scattering of those neutrinos. That's right. So they're not actually coming out at parallel. Exactly, but they're usually random. So if you look at the 327 00:47:19.450 --> 00:47:30.359 STFC-RAL-CR03 R61: surface of the, say, neutrino sphere surface, they're coming out to all angles. Exactly, yeah. So your initial graph showed two neutrinos coming out. 328 00:47:30.360 --> 00:47:45.680 STFC-RAL-CR03 R61: say, divergent. Yeah, it's… it's not actually correct. Well, it's… I think… I think what you can do is you can then play with, obviously, the angle that they're coming at us, which is what, you know, probably when we do these multi-angle, we will also… 329 00:47:45.680 --> 00:47:55.320 STFC-RAL-CR03 R61: pick those up random. I mean, you're entirely right, there's… there's no real reason why we get, like, streams, like, there will… there will be, 330 00:47:55.810 --> 00:48:02.480 STFC-RAL-CR03 R61: they will be scattered, and they'll come up different angles, yes. Yeah, totally, yeah. I think here was more… 331 00:48:02.730 --> 00:48:03.980 STFC-RAL-CR03 R61: I thought I'd make… 332 00:48:04.210 --> 00:48:12.980 STFC-RAL-CR03 R61: a picture that sort of shows the parameters rather than, necessarily. So, just another question. Were you actually considering, 333 00:48:13.030 --> 00:48:27.420 STFC-RAL-CR03 R61: the region between the foot and the star surface, so the earlier surface, and the shock, and you're considering that just vacuum. Absolutely. That's actually quite important, so the… 334 00:48:27.480 --> 00:48:40.080 STFC-RAL-CR03 R61: The matcha interaction is quite important. In fact, we can often show in this other simulations I've shown that if you actually include matching interaction, you could sometimes even quench the entire thing entirely. 335 00:48:40.970 --> 00:48:56.540 STFC-RAL-CR03 R61: We've removed it initially because we wanted to see whether, if left… if we assume it's maturing, which it clearly isn't, do we, you know, what is the physics that we're seeing there? And then the plan is to then add material interactions back 336 00:48:56.770 --> 00:49:06.999 STFC-RAL-CR03 R61: to try to see what, okay, does… or does that affect the dynamics that we're seeing? But yeah, definitely, I mean, you know, at the minute, this is not a realistic 337 00:49:07.250 --> 00:49:17.160 STFC-RAL-CR03 R61: supernova simulation, because it's missing… the matter is missing, there's… it's not enough neutrinos to really be 338 00:49:17.690 --> 00:49:30.320 STFC-RAL-CR03 R61: even competing with some of the mean field theories, but the idea was to try and construct this from the ground up, and then add the effects, one after the other, to see, okay, this does this, this part does that, etc, etc. 339 00:49:30.460 --> 00:49:46.900 STFC-RAL-CR03 R61: So, would the end game, your simulations actually explain the explosion? Because we don't know how the star explodes. Yeah. Exactly. So I think the end game… well, if we could explain the explosions, fantastic. I think… 340 00:49:46.900 --> 00:49:54.129 STFC-RAL-CR03 R61: We'll have to be probably a little bit more modest here and say, well, the end would be to already see if you have 341 00:49:54.210 --> 00:49:55.200 STFC-RAL-CR03 R61: maybe… 342 00:49:55.540 --> 00:50:15.010 STFC-RAL-CR03 R61: Quantum neutrinos, you know, neutrinos with a quantum description, and we're trying to see how can we go to see, can we maybe validate some of the midfield models, and then say, okay, they all seem to be alright, and then you could use the midfield models to describe 343 00:50:15.040 --> 00:50:17.900 STFC-RAL-CR03 R61: the properties reasonably accurately. 344 00:50:18.020 --> 00:50:25.680 STFC-RAL-CR03 R61: Or are we seeing some, sort of re-correlated effects that you're sort of missing out? 345 00:50:26.120 --> 00:50:36.350 STFC-RAL-CR03 R61: from, mean field, because you could do multiple angle mean field models, right? People do that, this is fine. I think the question is. 346 00:50:37.610 --> 00:50:44.610 STFC-RAL-CR03 R61: coming from something that is maybe more, like… I know, for example, in electronic structure theory. 347 00:50:44.800 --> 00:50:56.529 STFC-RAL-CR03 R61: this is not correct, that the mean field model misses out lots of correlated things, and we usually have to add it back. So the idea was to say, well, if we take this to neutrinos. 348 00:50:56.650 --> 00:50:59.639 STFC-RAL-CR03 R61: to neutrino physics, you will see a signal. 349 00:50:59.780 --> 00:51:17.579 STFC-RAL-CR03 R61: how much are we missing by using a meat field compared to an explicit calculation? I think that was the motivation behind it. And it may be that that then would explain some of the weirdness that would have, but it's still part of the physics that we need to add before we can say, this is a 350 00:51:17.950 --> 00:51:20.649 STFC-RAL-CR03 R61: But for a supernova type model. 351 00:51:20.820 --> 00:51:21.750 STFC-RAL-CR03 R61: I agree. 352 00:51:26.310 --> 00:51:40.980 STFC-RAL-CR03 R61: Sorry, I probably just didn't follow, but I didn't understand what advantage you were getting from the quantum community. You seem to be validating it all against classic law. Yeah, so there's only so much that you can do, 353 00:51:42.690 --> 00:51:44.829 STFC-RAL-CR03 R61: There's only so much that you can do 354 00:51:45.490 --> 00:51:52.410 STFC-RAL-CR03 R61: without the quantum computers. So, you can simulate this classically up to about… 355 00:51:53.420 --> 00:51:58.510 STFC-RAL-CR03 R61: 30 cubits, so 30 particles in total. 356 00:51:58.630 --> 00:52:05.379 STFC-RAL-CR03 R61: When you get to 35, 36, you need supercomputers. By the time you get 357 00:52:05.720 --> 00:52:11.019 STFC-RAL-CR03 R61: to 40, basically, I would probably have to use the whole of Iraq. 358 00:52:11.870 --> 00:52:21.890 STFC-RAL-CR03 R61: And I probably wouldn't even get that. So, you hit a limit on sort of your explicit calculations. So, the only alternative that you have is that you have to do mean refills. 359 00:52:22.120 --> 00:52:30.230 STFC-RAL-CR03 R61: So, our hope is that Once you get on a quantum computer, the quantum computer will happily give you 360 00:52:30.350 --> 00:52:40.410 STFC-RAL-CR03 R61: 100 qubits, and give you the result for that. The classic, you know, you will have to measure it, so you get the result, but you can, within the quantum computer, run the 361 00:52:40.520 --> 00:52:47.170 STFC-RAL-CR03 R61: want to, you know, have no wind field at all. You can have the total exact import result. 362 00:52:48.280 --> 00:52:49.709 STFC-RAL-CR03 R61: And I think… 363 00:52:49.910 --> 00:53:01.319 STFC-RAL-CR03 R61: What we're up against at the minute is making sure that we can do all the operations that we need to do without the cubits sort of decoheering, because we take too long to actually tell it what to do. 364 00:53:02.540 --> 00:53:06.850 STFC-RAL-CR03 R61: I mean, that's it. You're proving that that doesn't work? 365 00:53:07.400 --> 00:53:15.130 STFC-RAL-CR03 R61: Well, I think… I'm gonna assume that I'm doing it wrong, initially. I'm gonna go, well, it's… it's… 366 00:53:16.320 --> 00:53:24.499 STFC-RAL-CR03 R61: It's not working just because we're… the coherence time that we have on the machine at the minute is 367 00:53:24.920 --> 00:53:28.140 STFC-RAL-CR03 R61: Still quite… Oops. 368 00:53:28.820 --> 00:53:33.510 STFC-RAL-CR03 R61: And what might be some older machines that are better at this? 369 00:53:35.160 --> 00:53:48.189 STFC-RAL-CR03 R61: And it may just be that there's one clever way of doing it. So we're already working on things where, for example, not all the interactions are important, so we could try and prune some of this stuff down. There's… 370 00:53:48.430 --> 00:53:57.260 STFC-RAL-CR03 R61: different ways in which we could reformulate the propagation, for example. So there's… there's a few… quite a few tricks that we can still, you know, we're not out of tricks yet. 371 00:53:57.730 --> 00:54:06.050 STFC-RAL-CR03 R61: But it's a very… so the idea is, can we actually do it at all? You're right, it may be that we get to that and go, actually, this is… 372 00:54:06.200 --> 00:54:08.060 STFC-RAL-CR03 R61: Too complex a problem. 373 00:54:08.270 --> 00:54:11.039 STFC-RAL-CR03 R61: For the hardware that we have at the minute. 374 00:54:12.520 --> 00:54:17.470 STFC-RAL-CR03 R61: But I think, yeah, if you don't try a slow sniper, we'll never know what the right said. 375 00:54:18.810 --> 00:54:21.850 STFC-RAL-CR03 R61: Oh, sorry, you do. 376 00:54:22.390 --> 00:54:30.940 STFC-RAL-CR03 R61: So I… I first wanted to ask, like, how much energy is actually transferred by the nodes interacting with the, 377 00:54:31.050 --> 00:54:31.970 STFC-RAL-CR03 R61: Super. 378 00:54:32.210 --> 00:54:37.750 STFC-RAL-CR03 R61: so, we think that when 379 00:54:38.530 --> 00:54:44.030 STFC-RAL-CR03 R61: In sort of the later stage in, when you're… 380 00:54:44.420 --> 00:54:54.130 STFC-RAL-CR03 R61: creating the protonutral star, so the final star. That is actually quite a lot of energy that is… that you get from 381 00:54:54.370 --> 00:54:56.759 STFC-RAL-CR03 R61: Essentially, gravitational… 382 00:54:56.990 --> 00:55:04.739 STFC-RAL-CR03 R61: collapse. And most of that energy, in the estimation so far, at least 90%, comes off as 383 00:55:05.130 --> 00:55:11.960 STFC-RAL-CR03 R61: is going into the neutrinos. How much is then taken back. 384 00:55:12.340 --> 00:55:18.420 STFC-RAL-CR03 R61: is… I think the idea was… 385 00:55:18.680 --> 00:55:26.310 STFC-RAL-CR03 R61: So you can… you can calculate, sort of foods and rates and things like that, but essentially, all you need is to have enough energy to, sort of. 386 00:55:26.500 --> 00:55:30.210 STFC-RAL-CR03 R61: Tip the shock over to then… 387 00:55:30.340 --> 00:55:36.580 STFC-RAL-CR03 R61: get it to explore. So it's not that you need necessarily a lot, right? 388 00:55:37.070 --> 00:55:46.670 STFC-RAL-CR03 R61: Astrophysical units, right? A lot is probably quite a lot, but you still, you know, you don't need to have, like. 389 00:55:47.620 --> 00:55:49.610 STFC-RAL-CR03 R61: 10 to the 46 joules. 390 00:55:49.890 --> 00:56:07.569 STFC-RAL-CR03 R61: So it's in there for it to happen. You are… your shock is coming out, your informing matter is coming, so you're so… essentially, you just need to disrupt the equilibrium enough, then it just goes, okay, so essentially bubbles out. But there's loads of things 391 00:56:07.790 --> 00:56:25.030 STFC-RAL-CR03 R61: hidden behind that that I haven't talked about. For example, we know that these explosions are not symmetrical at all. They end up being really stretched. You know, all the simulations give you very… and even the observations give you very weird remnants from this. 392 00:56:25.170 --> 00:56:43.360 STFC-RAL-CR03 R61: And so there's some preferential… I mean, it could be that you just… like a bubble, you just burst one part, and then that's maybe what's causing it. We don't know. It could be that it's just due with the structure inside it, etc. That would also impact. So it's, good as… 393 00:56:43.610 --> 00:56:54.239 STFC-RAL-CR03 R61: it's good enough as long as it can just pass through some kind of threshold. Exactly, yeah, yeah, exactly. It's not… so what we're saying is it's not the neutrinos that are completely 394 00:56:54.490 --> 00:57:05.260 STFC-RAL-CR03 R61: driving the explosion itself. There's already some things happening to it. The neutrios might be there to help break the deadlock that you have, because, I mean. 395 00:57:05.570 --> 00:57:14.219 STFC-RAL-CR03 R61: Energy transfer through neutrinos Yeah, we're all kids then smarter, but it's not all so… super efficient. 396 00:57:15.060 --> 00:57:17.540 STFC-RAL-CR03 R61: Right. Although, all the words. 397 00:57:17.840 --> 00:57:23.009 STFC-RAL-CR03 R61: You wouldn't need the big detection and go, oh, yeah, look, super cross-section, we'll get those materials. 398 00:57:23.160 --> 00:57:27.069 STFC-RAL-CR03 R61: No, you go ahead. Thank you. 399 00:57:27.380 --> 00:57:35.060 STFC-RAL-CR03 R61: I actually had another question about the quantum computing part. Yeah. So it's more of a confusion, because when I've 400 00:57:35.200 --> 00:57:49.370 STFC-RAL-CR03 R61: I learned about quantum computing, it was usually, at the middle state, it's fine to go superposition, but at the final state, you have to, project it to, 100 or a 0. That's right, yeah. But it seems it's… 401 00:57:49.680 --> 00:57:50.769 STFC-RAL-CR03 R61: kind of something. 402 00:57:51.230 --> 00:58:04.790 STFC-RAL-CR03 R61: completely opposite of that. No, no, no, no, I think here you… ultimately, you still have to measure. You still have to say, the energy, you're measuring the few bits, and you'll get just 0 or 1. 403 00:58:05.270 --> 00:58:15.450 STFC-RAL-CR03 R61: The whole thing is, what they do in quantum computing is that they're trying to, sort of, engineer the superpositions or the entanglements so that they enable you 404 00:58:15.610 --> 00:58:18.729 STFC-RAL-CR03 R61: compute what you want. It's… 405 00:58:19.100 --> 00:58:24.240 STFC-RAL-CR03 R61: The tricky part, I think, is that a lot of people using 14 computers are trying to 406 00:58:24.400 --> 00:58:33.309 STFC-RAL-CR03 R61: simulate, or to do normal computing with it. So they're like, oh, they're representing numbers. But actually, the easiest thing for quantum computers to do is 407 00:58:33.480 --> 00:58:38.990 STFC-RAL-CR03 R61: just to do some quantum physics, because that's actually what it does. So, in all case. 408 00:58:39.010 --> 00:58:47.460 STFC-RAL-CR03 R61: we're making something more like an analog, I suppose, of your neutrinos, and you say, well, yeah, so we don't need 409 00:58:47.460 --> 00:59:06.260 STFC-RAL-CR03 R61: We just basically… it's a bit as if we had a detector there, and we say, well, is it an electronutrino or other neutrino? And then we just measure them, and all we need to do is just engineer, sort of, the dynamics, essentially, inside the multiple computer. 410 00:59:06.620 --> 00:59:15.089 STFC-RAL-CR03 R61: I want it to be, you know, headline-catching, I would say. A super number inside a quantum computing. That's really important. 411 00:59:15.580 --> 00:59:32.380 STFC-RAL-CR03 R61: Yeah, I mean, I got the impression that it was sort of like a miniature hardware Monte Carlo device. Yeah, well, at the minute, that's probably what it looks like, but hopefully we can make it a bit more… 412 00:59:32.550 --> 00:59:35.050 STFC-RAL-CR03 R61: For purpose. 413 00:59:35.460 --> 00:59:47.850 STFC-RAL-CR03 R61: Okay, Bob? Yeah, a couple of points. In the quantum, calculations you're doing, you're… you're representing neutrinos with qubits. Yes, and you were always, they were… 414 00:59:47.850 --> 00:59:55.619 STFC-RAL-CR03 R61: in base. So you did mention that there's a randomness to it. Yes. There's a random phase approximation that you didn't… 415 00:59:55.620 --> 01:00:08.369 STFC-RAL-CR03 R61: you alluded to it, but you didn't actually discuss. Yes. So, is that where the problem arises, in not being able to, let's say, get the right result? Yeah, so when you do it… so, in… 416 01:00:08.530 --> 01:00:11.890 STFC-RAL-CR03 R61: The classical approximations, well. 417 01:00:12.430 --> 01:00:18.939 STFC-RAL-CR03 R61: It's not… I'm calling it classical, as in, we're not going to do computer versions. You would… 418 01:00:19.110 --> 01:00:34.699 STFC-RAL-CR03 R61: typically use RPA, so you use a random phase approximation, or similarly, a sort of mean-field type approximation, where you're going to say, okay, that neutrino sees all the others, they'll wave… you know, you essentially have a separable wave function. 419 01:00:36.460 --> 01:00:43.019 STFC-RAL-CR03 R61: Key here is we don't need to have a separable wave function, so we could generate a state that is 420 01:00:45.060 --> 01:01:03.630 STFC-RAL-CR03 R61: all two materials all entangled together, not a separable state that you can't actual out, basically. And then we can propagate that state and see what the end result is. That's, I think, the difference between doing it that way or doing it using RPA or some of the other methods is 421 01:01:03.630 --> 01:01:10.250 STFC-RAL-CR03 R61: At some stage, you're sort of factoring out part of your system so that you can treat it. 422 01:01:11.130 --> 01:01:12.380 STFC-RAL-CR03 R61: Yeah, thanks. 423 01:01:13.070 --> 01:01:28.410 STFC-RAL-CR03 R61: One more point. I mean, in the neutrino problem, I mean, it was recognized that about 1% of the neutrino energy coming from the core has got to be dumped around about the shock wave, so that's the main problem. How does that neutrino energy 424 01:01:28.510 --> 01:01:45.020 STFC-RAL-CR03 R61: communicate with the matter behind the shock to revive the shock. So you've got to raise the temperature by about, say, well, up to about half an MAP in the material that is behind the shock. Yeah, exactly. So that's the big problem. And you also have only 425 01:01:45.220 --> 01:01:54.200 STFC-RAL-CR03 R61: pretty much one channel that really interacts with radioactive neutrinos, so if you… if you sort of… if your oscillations are, sort of. 426 01:01:54.210 --> 01:02:09.470 STFC-RAL-CR03 R61: dampen that much that all your electric neutrinos now become other neutrinos. You can't… And I think that's… that's the point I would try. What's interesting here is we're seeing the ones that would have the high energy, they basically just 427 01:02:09.790 --> 01:02:15.679 STFC-RAL-CR03 R61: ill. And you're, okay, so then it's not planned, but how much energy is then left? 428 01:02:15.830 --> 01:02:27.359 STFC-RAL-CR03 R61: in the sort of low-energy nutrients to actually do that, that we kind of solve the emissions overall. So I think that's what we're trying to… what we're trying to drive up for us, to try and see, is it then going to be 429 01:02:27.610 --> 01:02:39.850 STFC-RAL-CR03 R61: really abide for the split, although we have, like, a distribution, and is some of that removed from this by your, your sort of bluefield approximation? 430 01:02:41.850 --> 01:02:43.509 STFC-RAL-CR03 R61: Any questions from Tzu? 431 01:02:45.130 --> 01:02:47.770 STFC-RAL-CR03 R61: Please unmute if you have anything. 432 01:02:48.030 --> 01:02:50.710 STFC-RAL-CR03 R61: Looks like not. Anything else from room? 433 01:02:51.210 --> 01:03:00.620 STFC-RAL-CR03 R61: I would hold my questions for later lunch. Please do feel free to join us for lunch, and we'll be happy to interact with you. 434 01:03:01.460 --> 01:03:03.280 STFC-RAL-CR03 R61: So, let's thank our speaker. 435 01:03:07.580 --> 01:03:10.019 STFC-RAL-CR03 R61: Thank you, Emma. Thank you. 436 01:03:13.350 --> 01:03:15.490 STFC-RAL-CR03 R61: Oracle.