WEBVTT 1 00:00:01.480 --> 00:00:05.599 Welcome to the coret Side Quantum Physics podcast, an exploration 2 00:00:05.679 --> 00:00:10.880 of the fundamental structure of reality, where quantum laws govern matter, energy, 3 00:00:11.199 --> 00:00:16.239 and information. Here, uncertainty is a feature, not a flaw, 4 00:00:16.719 --> 00:00:19.239 and understanding begins at the smallest scales. 5 00:00:27.519 --> 00:00:29.519 I want you to try something with me today. It's 6 00:00:29.559 --> 00:00:31.719 a little mental exercise to get us started. 7 00:00:31.800 --> 00:00:32.520 Okay, I'm in. 8 00:00:32.600 --> 00:00:36.280 I want you to close your eyes seriously, unless you are, 9 00:00:36.640 --> 00:00:40.399 you know, currently operating heavy machinery or driving down the freeway. 10 00:00:41.000 --> 00:00:42.039 Just close them for a second. 11 00:00:42.079 --> 00:00:44.880 Safety first, please, But if you're safe, go for it 12 00:00:45.119 --> 00:00:45.920 right exactly. 13 00:00:46.479 --> 00:00:49.719 So picture your warning routine. You know the drill. You 14 00:00:49.759 --> 00:00:51.359 walk into that coffee shop you love. 15 00:00:51.560 --> 00:00:53.280 Uh huh, I can see it now. 16 00:00:53.520 --> 00:00:55.719 You know the one I'm talking about. It's always just 17 00:00:55.759 --> 00:00:57.960 a little bit too loud. The grinder is going in 18 00:00:57.960 --> 00:01:01.759 the background, and it smells like roasted beans and maybe 19 00:01:01.759 --> 00:01:03.560 a hint of rain if it's a gloomy day. 20 00:01:03.840 --> 00:01:04.480 Mm hm. 21 00:01:04.760 --> 00:01:07.159 You walk up to the counter and you order a latte. 22 00:01:06.879 --> 00:01:08.879 The classic choice, very good. 23 00:01:08.719 --> 00:01:12.760 The classic, and the barista who clearly takes their craft 24 00:01:12.879 --> 00:01:13.760 very very seriously. 25 00:01:13.840 --> 00:01:15.640 Oh yeah, the one with the wax mustache and the 26 00:01:15.680 --> 00:01:16.359 denim aper. 27 00:01:16.359 --> 00:01:19.159 That's the one. The whole vibe. They pour that steamed 28 00:01:19.200 --> 00:01:22.480 milk into the dark espresso and they do that specific 29 00:01:22.480 --> 00:01:24.640 little wrist flick at the end. You know what I'm 30 00:01:24.640 --> 00:01:25.120 talking about. 31 00:01:25.200 --> 00:01:28.719 The poor It's mesmerizing to watch it, really is it is. 32 00:01:29.400 --> 00:01:32.760 And boom there it is a perfect tulip pattern in 33 00:01:32.799 --> 00:01:38.040 the foam, crisp white lines against the dark coffee. It's symmetry, 34 00:01:38.439 --> 00:01:39.319 it's structure. 35 00:01:39.480 --> 00:01:41.400 It's a little piece of art that you are about 36 00:01:41.480 --> 00:01:42.159 to destroy. 37 00:01:42.480 --> 00:01:46.359 Exactly. It is beautiful and it's fleeting, so fleeting. Right 38 00:01:46.400 --> 00:01:49.719 now here is the experiment. Keep your eyes closed. Imagine 39 00:01:49.840 --> 00:01:52.120 taking that cup but it's hot in your hand and 40 00:01:52.319 --> 00:01:55.519 just giving it a violent swirl. Okay, I mean really 41 00:01:55.560 --> 00:01:58.200 shake it, agitate the whole thing. What happens to the tulip. 42 00:01:57.959 --> 00:02:01.719 Well, obviously it's obliterated. You don't have a tulip anymore. 43 00:02:01.760 --> 00:02:05.920 You have a beige, frothy mess. The milk mixes with 44 00:02:05.959 --> 00:02:08.240 the coffee, the pattern dissolves, and you are left with 45 00:02:08.280 --> 00:02:11.680 a tasty, but you know, visually boring drink. 46 00:02:11.879 --> 00:02:14.360 Right. That is what our intuition tells us. That is 47 00:02:14.360 --> 00:02:16.680 what common sense tells us. That is what's seeing the 48 00:02:16.719 --> 00:02:19.919 world every day tells us things mix, things mix, order 49 00:02:19.960 --> 00:02:23.560 turns into chaos. The tulip does not survive the swirl. 50 00:02:24.439 --> 00:02:24.879 It can't. 51 00:02:25.199 --> 00:02:27.080 It's the law of the universe, or at least the 52 00:02:27.159 --> 00:02:28.080 law of the kitchen table. 53 00:02:28.240 --> 00:02:29.919 What if I told you that in the quantum world, 54 00:02:30.080 --> 00:02:32.319 that logic just got completely flipped on its head. 55 00:02:32.479 --> 00:02:34.719 And this is where we leave the kitchen table behind. 56 00:02:34.840 --> 00:02:38.000 This is where it gets weird. Imagine you swirl that cup, 57 00:02:38.319 --> 00:02:41.000 you shake it, you tap it, you disturb it, and 58 00:02:41.039 --> 00:02:44.560 you look down and the tulip is still there. Oh wow, 59 00:02:44.840 --> 00:02:49.120 perfectly crisp every petal, define. It refuses to mix, it 60 00:02:49.159 --> 00:02:52.159 refuses to blend, It just stays. 61 00:02:52.479 --> 00:02:55.280 That is a perfect visualization of what we were talking 62 00:02:55.319 --> 00:02:58.199 about today. It sounds like magic or maybe a glitch 63 00:02:58.199 --> 00:03:00.800 in the simulation, right, it does. But it's actually a 64 00:03:00.919 --> 00:03:04.080 major breakthrough in physics known as statistical localization. 65 00:03:04.319 --> 00:03:06.560 And this isn't science fiction. This isn't a theory from 66 00:03:06.599 --> 00:03:09.159 fifty years ago that we're digging up. This is coming 67 00:03:09.199 --> 00:03:13.960 directly from a study published literally yesterday, February eighteenth, twenty 68 00:03:14.000 --> 00:03:17.000 twenty six. That's brand new, brand new, in the journal 69 00:03:17.120 --> 00:03:20.280 Nature Physics, and it's coming out of Duke University. 70 00:03:20.360 --> 00:03:23.400 That's right. It's fresh research and it is challenging some 71 00:03:23.439 --> 00:03:25.960 of our most i mean our most fundamental assumptions about 72 00:03:25.960 --> 00:03:29.360 how matter behaves when you start looking really really closely 73 00:03:29.400 --> 00:03:29.759 at it. 74 00:03:29.960 --> 00:03:32.719 So today, that's our whole journey. We are going to 75 00:03:32.840 --> 00:03:37.080 unpack how a team of scientists use a quantum simulator, 76 00:03:37.439 --> 00:03:39.719 which by the way, sounds as something straight out of 77 00:03:39.719 --> 00:03:42.639 a sci fi movie, it really does to essentially freeze 78 00:03:42.639 --> 00:03:44.879 the state of matter in a way that just shouldn't 79 00:03:44.919 --> 00:03:45.479 be possible. 80 00:03:45.639 --> 00:03:47.960 And we need to be clear from the top. This 81 00:03:48.080 --> 00:03:51.520 isn't just a cool party trick for atoms. This isn't 82 00:03:51.639 --> 00:03:53.960 just hey, look at this weird thing we found. This 83 00:03:54.039 --> 00:03:57.280 is a big deal. It's potentially the key to solving 84 00:03:57.319 --> 00:03:59.919 one of the biggest bottlenecks in quantum computing, which is 85 00:04:00.120 --> 00:04:01.120 memory storage. 86 00:04:01.560 --> 00:04:03.879 And if that wasn't enough, it might even help us 87 00:04:03.919 --> 00:04:07.280 understand the fundamental forces that hold the entire universe together. 88 00:04:07.400 --> 00:04:10.319 It connects the very small to the very big. It's 89 00:04:10.360 --> 00:04:12.479 the bridge between the micro and the macro. 90 00:04:12.639 --> 00:04:14.879 So grab your coffee, don't swirl it too hard or 91 00:04:14.919 --> 00:04:17.279 it maybe do. Just to prove physics still works in 92 00:04:17.319 --> 00:04:18.839 your kitchen, and let's get into it. 93 00:04:18.920 --> 00:04:19.439 Let's do it. 94 00:04:19.519 --> 00:04:23.240 To understand why this frozen latte effect is so profoundly weird, 95 00:04:23.680 --> 00:04:26.560 we first have to understand what's supposed to happen. You 96 00:04:26.639 --> 00:04:30.759 mentioned earlier that the tulip disappearing is obvious. Why is that? 97 00:04:30.959 --> 00:04:33.079 What is the physics behind the beige mess? 98 00:04:33.480 --> 00:04:36.560 So in the classical world, the world we live in 99 00:04:36.680 --> 00:04:40.199 the world of coffee cups and tables and cars, we 100 00:04:40.240 --> 00:04:43.000 are governed by a concept called thermalization. 101 00:04:43.439 --> 00:04:46.879 Thermalization, Okay, let's unpack that word. It sounds like it 102 00:04:46.920 --> 00:04:48.120 has something to do with heat. 103 00:04:48.399 --> 00:04:52.879 It does, but it's really about equilibrium, about things evening out. 104 00:04:53.319 --> 00:04:56.759 Think about dropping a single drop of dark blue ink 105 00:04:56.920 --> 00:04:58.720 into a glass of clear water. 106 00:04:59.000 --> 00:04:59.800 Okay, when you. 107 00:04:59.720 --> 00:05:02.199 First drop it in, for that first split second, it's 108 00:05:02.240 --> 00:05:05.399 a tight little ball of color. It has a specific location. 109 00:05:05.600 --> 00:05:06.959 It's organized right. 110 00:05:07.000 --> 00:05:08.319 You can point to it and say the ink is 111 00:05:08.399 --> 00:05:09.439 right there exactly. 112 00:05:09.600 --> 00:05:11.720 But if you walk away and come back in, say 113 00:05:11.800 --> 00:05:13.399 ten minutes, what do you see. 114 00:05:13.680 --> 00:05:17.079 The water is just light blue. It's all spread out. 115 00:05:17.079 --> 00:05:19.759 You can't tell where the drop landed anymore. The blob 116 00:05:19.879 --> 00:05:20.839 is totally gone. 117 00:05:20.879 --> 00:05:23.920 Precisely, the ink molecules have moved. They've gone from an 118 00:05:23.959 --> 00:05:26.959 area of high concentration that initial drop, to an area 119 00:05:26.959 --> 00:05:29.959 of low concentration the rest of the water they've spread 120 00:05:29.959 --> 00:05:31.439 out until everything. 121 00:05:31.040 --> 00:05:32.439 Is equal homogenized. 122 00:05:32.639 --> 00:05:36.480 That is equilibrium, and that process is thermalization. 123 00:05:36.759 --> 00:05:39.199 It's the same with temperature, right, that's the thermal part 124 00:05:39.199 --> 00:05:39.600 of the word. 125 00:05:40.160 --> 00:05:44.439 Yes. The source material uses this great simple example of 126 00:05:44.480 --> 00:05:46.680 a glass of ice water sitting on your kitchen table. 127 00:05:46.959 --> 00:05:49.240 You leave it there, right, The heat from the room 128 00:05:49.319 --> 00:05:52.560 transfers to the glass, the ice melts, the water warms up. 129 00:05:52.879 --> 00:05:55.800 Eventually the water, the glass, and the air in the 130 00:05:55.879 --> 00:05:59.879 room are all roughly the same temperature. They've reached equilibrium. 131 00:06:00.319 --> 00:06:03.879 Everything wants to settle down, Everything wants to mix. It's 132 00:06:03.920 --> 00:06:07.759 like the universe has this deep seated hatred of distinct things. 133 00:06:08.160 --> 00:06:10.160 It wants everything to be a lukewarm soup. 134 00:06:10.600 --> 00:06:12.399 That's a pretty good way to put it. This is 135 00:06:12.399 --> 00:06:16.160 all rooted in energy transport, energy moves. It flows from 136 00:06:16.199 --> 00:06:20.120 hot to cold, from organized to disorganized. In classical physics, 137 00:06:20.240 --> 00:06:24.040 systems naturally evolve toward this state of equilibrium. 138 00:06:24.079 --> 00:06:27.720 It's predictable. It's what we see every single day. Honestly, 139 00:06:27.759 --> 00:06:28.959 it's kind of comforting. Isn't it. 140 00:06:28.959 --> 00:06:30.920 It is comforting. We know that if we put something 141 00:06:30.920 --> 00:06:32.959 hot next to something cold, they'll meet in the middle. 142 00:06:33.000 --> 00:06:33.639 It makes sense. 143 00:06:33.759 --> 00:06:36.240 It's the arrow of time in a way. You can't 144 00:06:36.319 --> 00:06:39.279 unmix the ink. You can't unmelt the ice. No, once 145 00:06:39.319 --> 00:06:42.079 the latte is beige, you can't just shake it and 146 00:06:42.120 --> 00:06:43.240 get a perfect tool. 147 00:06:43.000 --> 00:06:45.519 Look back exactly. It's an irreversible process. 148 00:06:45.680 --> 00:06:49.279 But here comes the butt. I knew there was a 149 00:06:49.319 --> 00:06:49.959 butt coming. 150 00:06:50.240 --> 00:06:52.399 But this is not always how things behave. When you 151 00:06:52.519 --> 00:06:56.360 zoom in way way into the atomic and subatomic scales, 152 00:06:56.800 --> 00:06:58.240 the quantum realm, the. 153 00:06:58.279 --> 00:07:01.439 Quantum realm where the rules are and the points don't matter, 154 00:07:01.920 --> 00:07:04.839 or rather, the points matter a lot, but the rules 155 00:07:04.879 --> 00:07:06.680 are completely different from our intuition. 156 00:07:06.839 --> 00:07:09.560 They are definitely different. At this scale, we encounter a 157 00:07:09.600 --> 00:07:12.800 phenomenon called localization localization. 158 00:07:12.879 --> 00:07:16.199 Okay, so contrast that with thermalization. For me, if thermalization 159 00:07:16.360 --> 00:07:18.279 is all about mixing and spreading. 160 00:07:17.920 --> 00:07:21.040 Out, localization is the opposite. It's about staying put. So 161 00:07:21.120 --> 00:07:23.759 if thermalization is the ink spreading out to fill the 162 00:07:23.879 --> 00:07:27.480 entire glass, localization is the ink drop hitting the water 163 00:07:27.800 --> 00:07:30.120 and just staying there, staying as a drop, as a 164 00:07:30.160 --> 00:07:34.360 perfect tight little blue sphere, just suspended in the clear water. 165 00:07:34.680 --> 00:07:36.800 Why is there something holding it there? 166 00:07:37.120 --> 00:07:39.319 That's the weird part. Nothing is holding it. There are 167 00:07:39.360 --> 00:07:41.560 no walls keeping it there. It just doesn't spread. 168 00:07:41.959 --> 00:07:46.480 It feels wrong, like physically viscerally wrong. My brain doesn't 169 00:07:46.519 --> 00:07:46.839 like that. 170 00:07:47.279 --> 00:07:51.279 It feels very wrong. The source describes it as a 171 00:07:51.319 --> 00:07:55.720 situation where equilibrium spreading does not occur, even with nothing 172 00:07:55.879 --> 00:07:57.079 obviously preventing it. 173 00:07:57.199 --> 00:08:00.360 So it's just stubborn. The ink is just refue using 174 00:08:00.399 --> 00:08:02.480 to participate in the laws of physics as we know. 175 00:08:02.480 --> 00:08:06.040 Them in a way. Yes, the energy transport we talked 176 00:08:06.040 --> 00:08:09.120 about before, it just stops. Yeah, the system retains a 177 00:08:09.160 --> 00:08:13.920 memory of its original state the ink drop forever, instead 178 00:08:13.920 --> 00:08:15.879 of forgetting it and becoming a uniform mix. 179 00:08:16.000 --> 00:08:17.360 It remembers where it started. 180 00:08:17.519 --> 00:08:19.079 It remembers it doesn't thermalize. 181 00:08:19.120 --> 00:08:23.560 Okay, So that's the baseline weirdness of quantum localization. This 182 00:08:23.639 --> 00:08:26.199 isn't a brand new idea, right. Physicists have known about 183 00:08:26.199 --> 00:08:27.319 this concept for a little while. 184 00:08:27.360 --> 00:08:30.839 Correct. We've known about standard localization often it's called Anderson 185 00:08:30.920 --> 00:08:34.519 localization for decades. Usually happens when there's a lot of 186 00:08:34.639 --> 00:08:37.600 disorder or sort of dirt in a system that ends 187 00:08:37.639 --> 00:08:39.519 up trapping the particles. 188 00:08:39.159 --> 00:08:41.039 Like potholes in a road that stop traffic. 189 00:08:41.159 --> 00:08:43.960 That's a great analogy. Yeah, but this new paper from 190 00:08:44.080 --> 00:08:46.799 Duke is talking about something even more specific and frankly 191 00:08:46.840 --> 00:08:50.200 even weirder, isn't it. It's statistical localization. 192 00:08:49.840 --> 00:08:51.320 Right, and that's the new discovery. 193 00:08:51.519 --> 00:08:54.519 Yes, And to understand that, we really need to look 194 00:08:54.559 --> 00:08:59.279 at the experiment itself, because they didn't just stumble upon this. 195 00:08:59.399 --> 00:09:02.600 They had to build a very very complex machine to 196 00:09:02.679 --> 00:09:03.600 even see it. 197 00:09:03.960 --> 00:09:06.559 This wasn't something they just found lying around in nature. 198 00:09:06.559 --> 00:09:09.480 They had to engineer it precisely. Let's talk about the team. 199 00:09:09.559 --> 00:09:13.200 We have huonkin Low, she's an assistant professor of electrical 200 00:09:13.240 --> 00:09:15.919 and computer engineering and physics at Duke. 201 00:09:15.879 --> 00:09:19.759 And her colleagues, including Natalie Palko, who will definitely hear 202 00:09:19.759 --> 00:09:22.120 about later when we get to the theory side of things. 203 00:09:22.399 --> 00:09:25.159 It's a multidisciplinary effort, which is key here. 204 00:09:25.519 --> 00:09:29.080 And they build something called a neutral atom quantum simulator. Now, 205 00:09:29.080 --> 00:09:31.440 when I hear simulator, I'm thinking of software. I'm thinking 206 00:09:31.480 --> 00:09:35.840 of like the SIMS or a flight simulator on a PC. Right, 207 00:09:35.960 --> 00:09:37.919 But that's not what this is at all, is No, 208 00:09:37.960 --> 00:09:38.399 not at all. 209 00:09:38.759 --> 00:09:41.200 This is a piece of hardware. The source material calls 210 00:09:41.240 --> 00:09:43.840 it a tabletop setup. But don't let that fool you 211 00:09:43.840 --> 00:09:46.559 into thinking it's simple. It's incredibly sophisticated. 212 00:09:46.600 --> 00:09:47.600 So it's not code. 213 00:09:47.799 --> 00:09:51.960 It's not code. We aren't simulating quantum mechanics using ones 214 00:09:52.000 --> 00:09:54.679 and zeros on a normal chip. We are using actual 215 00:09:54.759 --> 00:09:58.159 quantum objects to simulate other quantum objects. 216 00:09:58.279 --> 00:10:01.080 So it's like using legos to SIMI light how bricks work, 217 00:10:01.399 --> 00:10:03.399 rather than drawing bricks on a computer screen. 218 00:10:03.519 --> 00:10:06.159 That's a perfect analogy. They are building a physical model 219 00:10:06.200 --> 00:10:07.559 of the physics they want to study. 220 00:10:07.759 --> 00:10:10.279 Okay, so what are the legos in this case? What 221 00:10:10.320 --> 00:10:11.720 are the actual building blocks? 222 00:10:11.799 --> 00:10:14.240 They used atoms of rubidium. 223 00:10:13.759 --> 00:10:16.840 Rubidium element thirty seven on the periodic table. 224 00:10:16.639 --> 00:10:19.840 That's the one, and they arrange these rubidium atoms into 225 00:10:19.879 --> 00:10:22.600 a one dimensional chain. So I want you to imagine 226 00:10:22.639 --> 00:10:26.159 a string of pearls. But the pearls are individual atoms 227 00:10:26.200 --> 00:10:27.679 and they're floating in a vacuum. 228 00:10:27.799 --> 00:10:30.960 Okay, string of atomic pearls. But how do you keep 229 00:10:30.960 --> 00:10:34.840 an atom from just flying away? You can't exactly glue 230 00:10:34.879 --> 00:10:36.879 it down. Atoms are wiggly little things. 231 00:10:36.919 --> 00:10:39.480 You use light. That's the amazing part. They used highly 232 00:10:39.519 --> 00:10:43.720 focused lasers they're often called optical tweezers to tightly control 233 00:10:43.759 --> 00:10:45.600 the position of each individual atom. 234 00:10:45.720 --> 00:10:46.559 Optical tweezers. 235 00:10:46.679 --> 00:10:49.039 Yeah, so you have this row of atoms, each one 236 00:10:49.120 --> 00:10:51.159 pinned in placed by its own beam of light. 237 00:10:51.519 --> 00:10:54.679 That is just it always blows my mind that we 238 00:10:54.720 --> 00:10:56.519 can actually do that here. Let me just hold this 239 00:10:56.639 --> 00:10:59.639 single atom for you with a flashlight. It sounds like 240 00:10:59.639 --> 00:11:00.679 something for Star Trek. 241 00:11:00.879 --> 00:11:05.440 It really is remarkable technology. The source highlights this high 242 00:11:05.519 --> 00:11:09.840 degree of quantum engineering. They are manipulating the fundamental building 243 00:11:09.879 --> 00:11:13.799 blocks of matter with incredible, almost unbelievable precision. 244 00:11:14.159 --> 00:11:15.960 But holding them in place is just step one, just 245 00:11:16.000 --> 00:11:16.440 step one. 246 00:11:16.480 --> 00:11:18.919 Step two is getting them to interact with each other. 247 00:11:19.000 --> 00:11:21.720 Right, because a frozen line of atoms doesn't tell you 248 00:11:21.799 --> 00:11:24.320 much about mixing if they aren't even allowed to talk 249 00:11:24.360 --> 00:11:25.559 to each other exactly. 250 00:11:25.720 --> 00:11:29.720 So, they used another laser to excite the atom's electrons. 251 00:11:29.919 --> 00:11:32.720 Excite them How what does that mean? To excite an electron? 252 00:11:32.919 --> 00:11:35.879 It means they use the laser's energy to push the 253 00:11:35.960 --> 00:11:39.279 electron into a higher energy state, a different orbit around 254 00:11:39.279 --> 00:11:42.480 the nucleus. When they do this, it causes the atom's 255 00:11:42.559 --> 00:11:44.440 behaviors to become intertwined. 256 00:11:44.720 --> 00:11:45.440 Oh okay. 257 00:11:45.480 --> 00:11:48.960 In quantum terms, we're dealing with things like entanglement and interaction. 258 00:11:49.519 --> 00:11:52.600 The atoms stop acting like solitary individuals and they start 259 00:11:52.600 --> 00:11:55.639 acting like a collective system. Their fates are linked. 260 00:11:55.960 --> 00:11:58.799 Okay, so we have a chain of rubidium atoms. They 261 00:11:58.799 --> 00:12:01.600 are pinned in place by l They are excited at 262 00:12:01.679 --> 00:12:04.919 interacting with each other. This is the choreography that the 263 00:12:04.960 --> 00:12:05.679 source talks about. 264 00:12:05.879 --> 00:12:08.960 Yes, the researchers set up this very specific initial state, 265 00:12:09.000 --> 00:12:11.080 and this is like drawing the tulip in the latte 266 00:12:11.120 --> 00:12:14.399 from They positioned everything perfectly, they set the energy levels 267 00:12:14.559 --> 00:12:17.559 just so, and then then they let it go. They 268 00:12:17.639 --> 00:12:19.399 let it go, They let the system run. 269 00:12:19.639 --> 00:12:21.840 They introduced the squirrel exactly. 270 00:12:22.279 --> 00:12:26.840 They allowed the engineered quantum evolution to happen. They released 271 00:12:26.879 --> 00:12:30.000 the atoms from that initial rigid control just enough to 272 00:12:30.000 --> 00:12:33.039 see what they would do. Would they thermalize? Would they mix? 273 00:12:33.360 --> 00:12:34.600 Would the ink spread? 274 00:12:34.840 --> 00:12:35.080 Yeah? 275 00:12:35.120 --> 00:12:37.960 Would the tulip dissolve? That's the moment of truth. 276 00:12:38.120 --> 00:12:41.080 That was the big question. And remember, in a normal system, 277 00:12:41.399 --> 00:12:44.600 or even in many quantum systems, you would absolutely expect 278 00:12:44.639 --> 00:12:47.759 interaction to lead to mixing. If I'm an excited atom, 279 00:12:47.799 --> 00:12:49.960 and I bump into my neighbor. I transfer some energy. 280 00:12:50.320 --> 00:12:53.120 That neighbor bumps into the next one. Eventually the energy 281 00:12:53.120 --> 00:12:54.200 is spread all over the place. 282 00:12:54.360 --> 00:12:55.600 Everything should average out. 283 00:12:55.679 --> 00:12:59.159 It should, but that's not what happened. No, they observed 284 00:12:59.240 --> 00:13:00.679 statistical localization. 285 00:13:01.240 --> 00:13:03.879 So did the atoms mix like the coffee foam. 286 00:13:04.120 --> 00:13:07.200 They did not. They stayed put, or rather their state 287 00:13:07.279 --> 00:13:07.759 stayed put. 288 00:13:07.799 --> 00:13:10.399 Almost all states are frozen. That's the quote from Wonky 289 00:13:10.399 --> 00:13:10.679 and Low. 290 00:13:10.799 --> 00:13:14.360 Almost all states are frozen. It's such a powerful and 291 00:13:14.399 --> 00:13:17.759 surprising statement. It defies the expectation of chaos. 292 00:13:18.279 --> 00:13:20.200 I want to dig into how this is different from 293 00:13:20.200 --> 00:13:22.840 that normal localization you mentioned earlier, said that was like 294 00:13:22.960 --> 00:13:26.879 potholes in the road. How is statistical localization different because 295 00:13:27.120 --> 00:13:29.840 the source makes a pretty specific and important distinction here. 296 00:13:30.440 --> 00:13:33.240 This is a nuanced but really crucial point that Low 297 00:13:33.320 --> 00:13:36.200 makes in the paper. In the usual form of localization 298 00:13:36.879 --> 00:13:40.279 that Anderson localization with the potholes, the properties of the 299 00:13:40.320 --> 00:13:42.799 system are pinned to a particular site, like. 300 00:13:42.759 --> 00:13:45.879 A specific location in space. So atom A belongs in 301 00:13:45.960 --> 00:13:48.519 seat one, atomy is in C two, and they can't 302 00:13:48.559 --> 00:13:49.320 move right. 303 00:13:49.399 --> 00:13:51.240 Think of it like a traffic gym where every single 304 00:13:51.240 --> 00:13:54.440 car is stuck exactly where it is. Nothing moves at all. 305 00:13:54.519 --> 00:13:57.440 The disorder in the road, the potholes, prevents any movement. 306 00:13:57.600 --> 00:13:59.600 You look at the GPS and that car is at 307 00:13:59.600 --> 00:14:01.000 the same co ordinate for an hour. 308 00:14:01.360 --> 00:14:05.600 Okay, total gridlock, every car for itself stuck in place. 309 00:14:05.840 --> 00:14:08.799 But in statistical localization it's different. And this is the 310 00:14:08.840 --> 00:14:11.799 mind bending part. The quote from the paper is here 311 00:14:12.240 --> 00:14:15.720 we see localization, even though the conserved properties are rather 312 00:14:15.840 --> 00:14:16.840 spread out. 313 00:14:16.600 --> 00:14:21.480 Spread out, but localized. That sounds like a contradiction. How 314 00:14:21.480 --> 00:14:23.919 can something be spread out and frozen at the same time. 315 00:14:24.039 --> 00:14:26.960 It does sound like a paradox, it doesn't it. Let's 316 00:14:27.000 --> 00:14:30.039 go back to the traffic jam analogy. In the old model, 317 00:14:30.240 --> 00:14:33.279 every car is stuck on the highway completely alone. In 318 00:14:33.320 --> 00:14:36.080 this new state, it's more like the cars might be 319 00:14:36.159 --> 00:14:38.159 able to drive around a little bit, maybe they can 320 00:14:38.200 --> 00:14:40.480 swap lanes with the cars right next to them, but 321 00:14:40.519 --> 00:14:43.679 they can never leave their specific little group of cars. 322 00:14:43.960 --> 00:14:47.679 The group itself is frozen in terms of its overall configuration, 323 00:14:47.799 --> 00:14:49.679 even if there's some internal movement. 324 00:14:50.480 --> 00:14:52.559 So it's not that every single atom is glued to 325 00:14:52.600 --> 00:14:56.320 a specific coordinate. It's that the pattern. The relationship between 326 00:14:56.360 --> 00:14:57.320 the atoms is. 327 00:14:57.240 --> 00:15:01.600 What's frozen exactly. The overall state is preserved. The source 328 00:15:01.639 --> 00:15:04.759 explains that this was actually theorized back in twenty twenty. 329 00:15:05.080 --> 00:15:08.080 The Fear predicted that in certain quantum systems you would 330 00:15:08.080 --> 00:15:11.320 find subsets of quantum states are connected to each other 331 00:15:11.480 --> 00:15:15.200 and otherwise remain disjointed from all other quantum states. 332 00:15:15.559 --> 00:15:18.360 Disjointed. That's a really key word here. 333 00:15:18.559 --> 00:15:22.440 It is. Imagine a big cocktail party. Usually everyone mingles. 334 00:15:22.679 --> 00:15:24.919 After an hour, you've probably talked to a bunch of 335 00:15:24.919 --> 00:15:28.440 different people. The room has mixed. That's thermalization. 336 00:15:28.679 --> 00:15:31.559 Okay, the room is buzzing, everyone is meeting new people, 337 00:15:31.720 --> 00:15:33.480 sharing information exactly. 338 00:15:33.840 --> 00:15:37.159 In this system, it's like the party immediately splits into 339 00:15:37.240 --> 00:15:40.879 tiny separate clicks. The people in click A talk to 340 00:15:40.960 --> 00:15:44.240 each other furiously. They're interacting, they're sharing energy, but only 341 00:15:44.279 --> 00:15:47.960 with each other, and they absolutely completely ignore click B, 342 00:15:48.279 --> 00:15:49.080 click C and. 343 00:15:48.960 --> 00:15:51.519 Click b and clickbe ignores everyone else. 344 00:15:51.320 --> 00:15:55.279 Too, everyone else. The room never mixes. The clicks remain disjointed. 345 00:15:55.639 --> 00:15:57.639 They form these little isolated islands. 346 00:15:57.679 --> 00:16:00.399 So the system is fragmented. It shatters into peace that 347 00:16:00.399 --> 00:16:01.240 don't communicate. 348 00:16:01.600 --> 00:16:05.559 Yes, the technical term is a fragmented state space. And 349 00:16:05.600 --> 00:16:08.440 because these fragments don't talk to each other, the information 350 00:16:08.519 --> 00:16:12.000 that's contained within them doesn't leak out, doesn't dissipate into 351 00:16:12.000 --> 00:16:13.759 the rest of the system. It's protected. 352 00:16:14.320 --> 00:16:16.200 So if we bring this all the way back to 353 00:16:16.279 --> 00:16:21.320 the latte, if my latte had statistical localization, the milk 354 00:16:21.399 --> 00:16:24.399 molecules might be dancing around with other milk molecules in 355 00:16:24.440 --> 00:16:27.320 their own little cleek, right, but they refuse to acknowledge 356 00:16:27.360 --> 00:16:29.840 the existence of the coffee molecules next to them. 357 00:16:30.240 --> 00:16:32.879 Roughly speaking, yes, that's a great way to think about it. 358 00:16:33.200 --> 00:16:35.519 The tulip pattern is made of milk. If the milk 359 00:16:35.559 --> 00:16:38.759 molecules refuse to integrate with the coffee molecules, the tulip 360 00:16:38.799 --> 00:16:42.639 pattern stays. Even if you swirl the cup. The swirling 361 00:16:42.759 --> 00:16:46.879 moves the whole liquid around, but the internal separation remains. 362 00:16:47.360 --> 00:16:49.080 The cleek's hold strong. 363 00:16:49.200 --> 00:16:51.799 Low calls is very, very weird, and I have to 364 00:16:51.840 --> 00:16:52.360 agree with her. 365 00:16:52.399 --> 00:16:55.440 And she's right too, she says, in this imaginary example, 366 00:16:55.519 --> 00:16:58.080 we would have expected the elements to mix together to 367 00:16:58.120 --> 00:17:01.440 reach equilibrium, and yet we still some how see localization. 368 00:17:01.960 --> 00:17:03.039 It's a genuine surprise. 369 00:17:03.360 --> 00:17:05.720 It's weird, but she also says it could be a 370 00:17:05.759 --> 00:17:09.359 powerful feature, And this brings us to the really important 371 00:17:09.400 --> 00:17:13.519 part of this whole discussion, the so what why do 372 00:17:13.599 --> 00:17:16.960 we care if Adam's form clicks? Why does it matter 373 00:17:17.000 --> 00:17:20.200 if my hypothetical quantum latte doesn't mix well. 374 00:17:20.240 --> 00:17:23.359 The first big application, and maybe the most immediate one, 375 00:17:23.599 --> 00:17:27.640 is the holy grail of modern technology quantum computing. 376 00:17:27.880 --> 00:17:30.200 Right. We hear about quantum computers all the time. They're 377 00:17:30.200 --> 00:17:33.799 supposed to be faster, smarter, solve impossible problems, but they're 378 00:17:33.799 --> 00:17:37.119 also incredibly fragile, aren't they? That's the catch. 379 00:17:37.240 --> 00:17:40.920 Incredibly the biggest problem, the single biggest obstacle in building 380 00:17:40.960 --> 00:17:46.119 a useful, large scale quantum computer is something called decohuans. 381 00:17:45.720 --> 00:17:47.799 Which is basically the system just falling apart. 382 00:17:47.920 --> 00:17:52.119 It's the coffee mixing, it's thermalization. Quantum states, the quibits 383 00:17:52.119 --> 00:17:55.240 that do the computing are ridiculously delicate. Any little bit 384 00:17:55.240 --> 00:17:57.599 of noise from the environment, a tiny change in temperature, 385 00:17:57.640 --> 00:18:01.240 or a stray electromagnetic field, even the simple passage of 386 00:18:01.319 --> 00:18:03.960 time causes the quantum information to degrade. 387 00:18:04.079 --> 00:18:06.279 It leaks out, It leaks out. 388 00:18:06.119 --> 00:18:10.039 It thermalizes, it turns into that beige uniform mess ah, 389 00:18:10.079 --> 00:18:12.880 and when your information turns into a beige mess, you've 390 00:18:12.920 --> 00:18:15.920 lost your data. Your calculation is completely ruined. 391 00:18:16.000 --> 00:18:18.279 So if you want a quantum computer to actually work 392 00:18:18.319 --> 00:18:20.720 for more than a fraction of a second, you need 393 00:18:20.759 --> 00:18:23.319 a way to keep the ink blue and the water clear. 394 00:18:23.920 --> 00:18:27.200 You need to preserve the state precisely. You need a 395 00:18:27.200 --> 00:18:30.039 way to store information that is, and this is a 396 00:18:30.119 --> 00:18:35.119 quote from the paper robust to unpredictable surroundings. You need 397 00:18:35.240 --> 00:18:38.440 a memory system that fights back against entropy. 398 00:18:38.279 --> 00:18:41.039 And statistical localization offers a path to that. 399 00:18:41.319 --> 00:18:45.799 It offers a very exciting pathway. Low says, its implications 400 00:18:45.799 --> 00:18:49.640 for robustly storing information in a quantum system are quite exciting. 401 00:18:50.079 --> 00:18:52.960