WEBVTT 1 00:00:01.480 --> 00:00:05.599 Welcome to the quart 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 00:00:27.679 --> 00:00:31.079 So on December thirtieth, twenty twenty five, there is this 6 00:00:31.280 --> 00:00:33.759 massive publication in the Science bulletin. 7 00:00:33.439 --> 00:00:37.079 Yeah, the research from Shaolongsu's team at Shanksy University. 8 00:00:36.759 --> 00:00:40.719 Exactly, and they documented a milestone that fundamentally shifts how 9 00:00:40.719 --> 00:00:44.280 we scale quantum communication networks. I mean, we are talking 10 00:00:44.280 --> 00:00:49.520 about the realization of controllable, deterministic quantum teleportation of multiple 11 00:00:49.520 --> 00:00:54.079 side band quomo right, simultaneous parallel teleportation of up to 12 00:00:54.240 --> 00:00:57.679 five side band quomodes. And they did this within a 13 00:00:57.719 --> 00:01:01.920 tight twenty four megahertz bandwidth, hitting state transfer fidelities of 14 00:01:01.960 --> 00:01:03.359 around seventy. 15 00:01:02.960 --> 00:01:05.760 Percent, which is a huge structural departure from the old 16 00:01:05.959 --> 00:01:10.920 serial teleportation constraints. It's a game changer for network scalability. 17 00:01:10.400 --> 00:01:13.599 It really is. But to really unpack this development, we 18 00:01:13.640 --> 00:01:15.840 need to break it down step by step. We have 19 00:01:15.879 --> 00:01:20.239 to start with the foundational mechanics of continuous variable quantum teleportation. 20 00:01:20.480 --> 00:01:23.200 Because if you don't define the strict boundaries of quantum 21 00:01:23.200 --> 00:01:26.280 state transfer first, the rest of the experiment won't make. 22 00:01:26.159 --> 00:01:28.920 Sense, right, and you have to understand the strict academic 23 00:01:28.959 --> 00:01:31.799 definition of quantum teleportation out of the gate. So let's 24 00:01:31.799 --> 00:01:32.719 define that mechanism. 25 00:01:32.959 --> 00:01:37.439 Well, you have to define quantum teleportation strictly as the 26 00:01:37.480 --> 00:01:40.640 transfer of the information that defines a quantum state from 27 00:01:40.719 --> 00:01:42.000 one physical location to. 28 00:01:42.000 --> 00:01:44.680 Another, information being the keyword there. 29 00:01:44.840 --> 00:01:49.040 Exactly. You must separate this concept entirely from the physical 30 00:01:49.079 --> 00:01:53.439 translation of matter. In this protocol, the original physical carrier 31 00:01:53.480 --> 00:01:56.439 at the source, it doesn't travel through space to get. 32 00:01:56.319 --> 00:01:58.680 To the destination, and matter was moving right. 33 00:01:58.840 --> 00:02:01.920 Instead, the exact quantum state, which is basically the mathematical 34 00:02:01.959 --> 00:02:05.439 description of the system's properties. That state is transmitted and 35 00:02:05.439 --> 00:02:08.879 then imposed onto a distinct, pre existing physical carrier at 36 00:02:08.879 --> 00:02:09.560 the destination. 37 00:02:09.840 --> 00:02:12.319 And to pull that off, the mechanism relies on two 38 00:02:12.360 --> 00:02:13.960 fundamental resources, a. 39 00:02:14.000 --> 00:02:18.120 Dual resource dependency. Yeah, you need shared quantum entanglement and 40 00:02:18.159 --> 00:02:20.639 you need a standard classical communication channel. 41 00:02:20.840 --> 00:02:23.840 Let's talk about the entanglement part first, that provides the 42 00:02:23.879 --> 00:02:26.520 non local correlation between the sender and the receiver. 43 00:02:26.719 --> 00:02:30.719 Mm hm. You always begin with a bipartite entangled state. 44 00:02:31.280 --> 00:02:34.599 People often call this an Einstein Podolski Rosen pair or 45 00:02:34.639 --> 00:02:35.520 an EPR pair. 46 00:02:35.759 --> 00:02:38.599 So you have this pair, and one half stays with 47 00:02:38.680 --> 00:02:41.719 the sender and the other half goes to the receiver, right, And. 48 00:02:41.680 --> 00:02:44.199 When the center has an unknown quantum state that they 49 00:02:44.319 --> 00:02:47.599 want to teleport, they don't just measure it directly. They 50 00:02:47.639 --> 00:02:50.840 perform a joint measurement on both the unknown state and 51 00:02:50.919 --> 00:02:52.879 their half of the entangled EPR. 52 00:02:52.639 --> 00:02:56.560 Pair, specifically a Bell state measurement exactly. But and this 53 00:02:56.639 --> 00:02:59.080 is crucial, you have to note that performing this joint 54 00:02:59.120 --> 00:03:03.439 measurement in inherently destroys the original quantum state at the source. 55 00:03:03.840 --> 00:03:07.240 Yeah, it has to. That satisfies the no deleting theorem 56 00:03:07.280 --> 00:03:11.639 of quantum mechanics, which operates right alongside the non cloning theorem. 57 00:03:11.759 --> 00:03:14.400 You can't just make a copy, right, So the joint 58 00:03:14.400 --> 00:03:17.840 measurement projects the combined system into a specific state, and 59 00:03:17.879 --> 00:03:22.080 that projection extracts two discrete pieces of classical. 60 00:03:21.639 --> 00:03:24.639 Data, and that data represents the measurement outcome. 61 00:03:24.360 --> 00:03:27.360 Which brings us to the second resource, the classical channel. 62 00:03:27.479 --> 00:03:31.360 Yeah, the center takes this extracted classical data and transmits 63 00:03:31.360 --> 00:03:35.280 it to the receiver using a totally standard classical communication 64 00:03:35.400 --> 00:03:37.879 channel fiber optics, radio, whatever. 65 00:03:37.800 --> 00:03:40.719 And because it's a classical channel, it is strictly bound 66 00:03:40.719 --> 00:03:41.319 by the speed of. 67 00:03:41.360 --> 00:03:45.800 Light, which is how we ensure quantum teleportation doesn't violate causality. 68 00:03:46.400 --> 00:03:50.120 You aren't sending information faster than light. The classical message 69 00:03:50.319 --> 00:03:53.400 basically acts as a set of precise operational instructions. 70 00:03:53.479 --> 00:03:56.360 So the receiver gets this classical data. 71 00:03:56.520 --> 00:04:01.000 And upon receiving it, they apply specific unitary transformation to 72 00:04:01.080 --> 00:04:04.159 their half of the entangled pair, usually a sequence of 73 00:04:04.199 --> 00:04:05.919 phase and amplitude displacements. 74 00:04:06.479 --> 00:04:09.759 And because of those initial entanglement correlations. 75 00:04:09.159 --> 00:04:13.639 Exactly applying those specific local operations, which are conditioned entirely 76 00:04:13.680 --> 00:04:17.560 on the sender's classical measurement results. It literally forces the 77 00:04:17.600 --> 00:04:21.519 receiver's particle to assume the exact quantum state of the 78 00:04:21.519 --> 00:04:23.199 original input particle. 79 00:04:22.959 --> 00:04:24.879 The one that was destroyed at the source. 80 00:04:24.720 --> 00:04:28.279 Right the quantum information is perfectly reconstructed at the destination. 81 00:04:28.560 --> 00:04:31.600 So it's that interaction between the pre shared quantum entanglement 82 00:04:32.000 --> 00:04:35.160 and the classical feed forward mechanism that is the strict 83 00:04:35.160 --> 00:04:37.000 requirement for state transfer. 84 00:04:36.879 --> 00:04:40.160 And establishing that rigorous definition is so important because it 85 00:04:40.199 --> 00:04:43.120 addresses a massive misconception in the public discourse. 86 00:04:43.360 --> 00:04:44.680 Oh, the Star Trek question. 87 00:04:44.839 --> 00:04:48.279 Always people are constantly asking about the timeline for physical 88 00:04:48.279 --> 00:04:52.959 teleportation of macroscopic objects, like you see commentary asking if 89 00:04:52.959 --> 00:04:56.560 we'll be teleporting physical matter not just data, within the 90 00:04:56.600 --> 00:04:57.800 next decade. 91 00:04:57.519 --> 00:05:01.319 Which is well, you have to methodically separate macroscopic physical 92 00:05:01.360 --> 00:05:06.040 transport from the transfer of quantum information across defined Hilbert spaces. 93 00:05:06.519 --> 00:05:07.480 They're not the same thing. 94 00:05:07.720 --> 00:05:11.000 The distinction really comes down to dimensionality and thermodynamics. Right. 95 00:05:11.040 --> 00:05:14.439 Absolutely, a quantum state like what we use in continuous 96 00:05:14.519 --> 00:05:19.000 variable teleportation. It's a mathematical description of a continuous spectrum 97 00:05:19.199 --> 00:05:22.920 of observables like the position and momentum quadratures of an 98 00:05:22.959 --> 00:05:24.040 electromagnetic field. 99 00:05:24.160 --> 00:05:27.079 So when they teleport this state, they're just transferring exact 100 00:05:27.160 --> 00:05:30.399 quantum probability distributions to a new set of photons. 101 00:05:30.560 --> 00:05:35.040 Right. But macroscopic physical matter, like a biological organism or 102 00:05:35.040 --> 00:05:37.360 even just a coffee mug, it's made of atoms on 103 00:05:37.399 --> 00:05:39.319 the scale of a Goadro's number. 104 00:05:39.120 --> 00:05:41.040 Ten to the twenty third power. 105 00:05:40.879 --> 00:05:43.800 Roughly, yeah, and every single one of those atoms is 106 00:05:43.839 --> 00:05:46.480 continuously interacting with its thermal environment. 107 00:05:46.240 --> 00:05:49.360 Which causes rapid environmental decoherence instantly. 108 00:05:49.920 --> 00:05:53.279 It destroys the fragile quantum states you would need for entanglement. 109 00:05:53.839 --> 00:05:56.120 And even if you could somehow isolate it, if you 110 00:05:56.160 --> 00:05:59.560 calculate the sheer volume of information required to specify the 111 00:05:59.600 --> 00:06:02.879 complete quantum state of a macroscopic. 112 00:06:02.240 --> 00:06:03.759 Object, it's unfathomable. 113 00:06:03.879 --> 00:06:07.680 It yields a data quantity that completely exceeds the theoretical 114 00:06:07.680 --> 00:06:11.560 limits of any classical communication channel we can even conceptualize 115 00:06:11.639 --> 00:06:14.439 right now. It violates the Bekenstein limit. 116 00:06:14.759 --> 00:06:18.680 So anticipating physical teleportation of matter based on these quantum 117 00:06:18.680 --> 00:06:22.680 state transfer breakthroughs is just a fundamental misapplication of the physics. 118 00:06:22.879 --> 00:06:26.959 Entirely. The Shangxi University research is strictly confined to manipulating 119 00:06:27.000 --> 00:06:32.160 and transferring quantum information encoded in optical fields, not relocating mass. 120 00:06:32.360 --> 00:06:35.000 Okay, So with that cleared up, to really comprehend the 121 00:06:35.040 --> 00:06:38.759 specific technical bottleneck this team overcame, you have to distinguish 122 00:06:38.839 --> 00:06:42.759 between discrete variable systems and continuous variable system. 123 00:06:42.560 --> 00:06:45.920 Right, because most introductory physics focuses strictly on discrete systems. 124 00:06:46.199 --> 00:06:49.319 Using the quibbit as the foundational unit, equibent operates in 125 00:06:49.360 --> 00:06:53.560 a finite dimensional Hilbert space. It represents discrete states. 126 00:06:53.560 --> 00:06:57.079 Like a single photon's polarization, being either horizontal. 127 00:06:56.639 --> 00:07:02.120 Or vertical exactly, but continuous variable or CV systems they 128 00:07:02.160 --> 00:07:06.959 operate on a totally distinct mathematical foundation. The quantum information 129 00:07:07.160 --> 00:07:11.600 is encoded into observables that have a continuous spectrum of eigenvalues, 130 00:07:11.720 --> 00:07:12.000 and that. 131 00:07:12.000 --> 00:07:15.680 Continuous spectrum requires you to operate within an infinite dimensional 132 00:07:15.759 --> 00:07:20.519 Hilbert space in quantum optics, which is where this experiment lives. 133 00:07:21.000 --> 00:07:25.319 These continuous observables are typically the amplitude and phase quadratures 134 00:07:25.639 --> 00:07:27.360 of an electromagnetic field. 135 00:07:27.199 --> 00:07:31.160 Which are mathematically analogous to the position and momentum of 136 00:07:31.199 --> 00:07:33.079 a quantum harmonic oscillator. 137 00:07:33.279 --> 00:07:36.240 Right. And the beautiful thing about these continuous variables is 138 00:07:36.240 --> 00:07:40.120 that they allow for deterministic processing and highly efficient detection 139 00:07:40.399 --> 00:07:42.160 using Hamidine detectors. 140 00:07:41.839 --> 00:07:44.959 Which measure the interference between the quantum signal and a 141 00:07:45.040 --> 00:07:47.079 really strong classical reference. 142 00:07:46.680 --> 00:07:49.879 Beam the local oscillator. Yeah. And within this framework, we 143 00:07:49.959 --> 00:07:53.160 have to define the concept of a quomode, because it's 144 00:07:53.199 --> 00:07:54.360 not a coupit, right. 145 00:07:54.360 --> 00:07:56.319 A coupit is a two level system, but. 146 00:07:56.399 --> 00:08:00.319 A qualm mode represents a quantum harmonic oscillator. They can 147 00:08:00.319 --> 00:08:04.519 contain an arbitrary number of photons. It carries information in 148 00:08:04.560 --> 00:08:05.800 its continuous. 149 00:08:05.360 --> 00:08:09.759 Quadratures, and in this experiment they used sideband quomodes. You 150 00:08:09.800 --> 00:08:12.800 can conceptualize a sideband quomode by just looking at the 151 00:08:12.800 --> 00:08:14.279 frequency spectrum. 152 00:08:13.839 --> 00:08:15.800 Of an optical field like a radiodial. 153 00:08:15.959 --> 00:08:19.000 Exactly, if you have a primary beam of light acting 154 00:08:19.040 --> 00:08:23.120 as your carrier frequency, you can generate distinct frequency channels 155 00:08:23.160 --> 00:08:25.639 separated from that carrier by specific intervals. 156 00:08:25.680 --> 00:08:29.480 And those distinct channels writing right alongside the primary optical 157 00:08:29.519 --> 00:08:31.839 field are the sidebands. 158 00:08:31.360 --> 00:08:35.519 And each individual sideband can be treated as an independent quomode. 159 00:08:35.600 --> 00:08:39.159 It can carry its own continuous quantum information. 160 00:08:38.840 --> 00:08:43.240 Which is incredibly powerful for massive data transmission. By multiplexing 161 00:08:43.279 --> 00:08:47.759 quantum information across multiple distinct frequencies, you optimize the capacity 162 00:08:47.799 --> 00:08:49.360 of your physical transmission medium. 163 00:08:49.440 --> 00:08:53.440 But there's been a massive operational constraint historically, right, continuous 164 00:08:53.559 --> 00:08:57.600 variable quantum teleportation has effectively been stuck as a serial, 165 00:08:58.039 --> 00:08:59.159 one at a time process. 166 00:08:59.519 --> 00:09:03.799 Yeah, the limitation prior to this Shanxy breakthrough technical limits 167 00:09:03.879 --> 00:09:08.840 in generating multipart tit entanglement and then synchronously manipulating the 168 00:09:08.840 --> 00:09:14.080 classical feed forward channels. Meant researchers were basically constrained to 169 00:09:14.240 --> 00:09:18.200 teleporting a single sideband quimode during any given run. 170 00:09:18.080 --> 00:09:22.480 Which severely restricts building scalable quantum networks. You can look 171 00:09:22.519 --> 00:09:25.440 at this limitation by drawing a direct analogy to classical 172 00:09:25.519 --> 00:09:26.600 telecommunication like. 173 00:09:26.559 --> 00:09:27.720 The fiber optic Internet. 174 00:09:27.840 --> 00:09:32.559 Exactly in our standard global Internet infrastructure, data isn't transmitted 175 00:09:32.559 --> 00:09:36.360 sequentially on a single frequency channel. The whole system relies 176 00:09:36.440 --> 00:09:39.000 on wavelength division multiplexing WDM. 177 00:09:39.399 --> 00:09:43.639 Right WDM transmits multiple data streams at slightly different wavelengths 178 00:09:43.679 --> 00:09:45.919 simultaneously over a single optical fighter. 179 00:09:46.080 --> 00:09:49.320 So transitioning from serial transmission to parallel transmission is the 180 00:09:49.360 --> 00:09:52.919 foundational requirement for network scalability. You can't build a global 181 00:09:52.960 --> 00:09:54.159 network one channel at a time. 182 00:09:54.240 --> 00:09:56.799 No, you really can't. And the absence of a parallel 183 00:09:56.840 --> 00:10:01.360 transmission capability in entanglement based ontom communication has been this 184 00:10:01.440 --> 00:10:03.879 critical technical hurdle for years. 185 00:10:04.039 --> 00:10:07.159 Because if a quantum network is stuck doing serial teleportation, 186 00:10:07.639 --> 00:10:10.600 increasing your bandwidth means you have to linearly expand your 187 00:10:10.639 --> 00:10:11.519 physical hardware. 188 00:10:11.600 --> 00:10:16.000 It's a nightmare. You would need separate optical parametric oscillators, 189 00:10:16.039 --> 00:10:20.360 separate beam splitters, separate homodye detection systems for every single 190 00:10:20.399 --> 00:10:22.600 individual frequency channel you want to transmit. 191 00:10:22.720 --> 00:10:26.080 The architectural redundancy is just highly inefficient. 192 00:10:25.639 --> 00:10:29.720 And practically non scalable. So transitioning from the serial teleportation 193 00:10:29.799 --> 00:10:34.600 of a single quo mode to the simultaneous parallel teleportation 194 00:10:34.679 --> 00:10:39.080 of multiple sideband quomodes that is the necessary evolutionary step. 195 00:10:39.320 --> 00:10:43.480 It's like moving from early radio broadcasting to complex multiplexed 196 00:10:43.600 --> 00:10:47.360 broadband networks exactly, which brings us to the actual methodology 197 00:10:47.399 --> 00:10:51.639 published by Selanngsu and the team. Because they specifically targeted 198 00:10:51.679 --> 00:10:54.200 this requirement for parallel transmission, and. 199 00:10:54.120 --> 00:10:57.320 They achieved it by implementing an advanced mechanism of phase 200 00:10:57.360 --> 00:11:00.000 control within the classical communication channel. 201 00:11:00.399 --> 00:11:03.639 Let's examine the mechanics of that classical phase tuning. How 202 00:11:03.679 --> 00:11:06.000 did they bypass the serial bottleneck? 203 00:11:06.200 --> 00:11:09.960 Well, the methodology relies heavily on manipulating the final stage 204 00:11:09.960 --> 00:11:14.679 of the teleportation protocol. Like we established earlier, the protocol 205 00:11:14.720 --> 00:11:19.440 requires the sender to extract two classical signals via homodne 206 00:11:19.440 --> 00:11:23.000 detection and send them to the receiver right. The receiver 207 00:11:23.080 --> 00:11:26.919 then uses these electronic signals to drive electro optic modulators. 208 00:11:27.440 --> 00:11:31.399 Those modulators apply the required amplitude and phase displacements to 209 00:11:31.519 --> 00:11:35.000 their half of the entangled optical field to reconstruct the state. 210 00:11:35.440 --> 00:11:37.919 Okay, so what did SHANKSY do differently here? 211 00:11:38.200 --> 00:11:42.000 They introduced highly precise dynamic phase shifts directly into those 212 00:11:42.000 --> 00:11:46.080 classical electronic channels. They didn't just passively transmit the raw 213 00:11:46.080 --> 00:11:48.960 measurement data. They carefully tuned the phases of the two 214 00:11:49.039 --> 00:11:53.639 classical channels while concurrently selecting different adjustable radio frequency signals. 215 00:11:53.799 --> 00:11:56.519 So how does the RF selection interact with the classical 216 00:11:56.559 --> 00:11:57.279 phase tuning? 217 00:11:57.679 --> 00:12:01.480 By shifting the phase of the classical signal, basically delaying 218 00:12:01.559 --> 00:12:04.360 or advancing the timing of the electronic waveform, and then 219 00:12:04.399 --> 00:12:07.720 coordinating that specific phase shift with a selected radio frequency, 220 00:12:08.000 --> 00:12:09.879 they created a targeted resonance. 221 00:12:09.480 --> 00:12:13.399 Condition, and this resonance condition dictates how the electro optic 222 00:12:13.480 --> 00:12:15.840 modulators interact with the optical field. 223 00:12:15.960 --> 00:12:21.039 Precisely, the phase matching condition determines which specific sideband frequency 224 00:12:21.399 --> 00:12:25.879 on the receiver's optical field will actually undergo the displacement operation. 225 00:12:25.679 --> 00:12:30.159 Because under standard conditions without dynamic phase tuning, the classical 226 00:12:30.200 --> 00:12:34.320 signal would only correctly displace and reconstruct the quantum state 227 00:12:34.679 --> 00:12:37.960 for a single predetermined sideband, right, it would. 228 00:12:37.720 --> 00:12:40.960 Just be serial again. But by synthesizing the classical signal 229 00:12:40.960 --> 00:12:45.799 with multiple tuned radio frequency components and applying precise calculated 230 00:12:45.840 --> 00:12:47.879 phase shift to each component. 231 00:12:47.600 --> 00:12:51.879 The receiver's electro optic modulators can simultaneously apply the correct 232 00:12:52.039 --> 00:12:56.840 independent displacement operations to multiple distinct sideband frequencies on the 233 00:12:56.960 --> 00:12:58.279 single optical carrier. 234 00:12:58.519 --> 00:13:01.960 The classical channel is effect multiplexed. It allows it to 235 00:13:01.960 --> 00:13:05.440 deliver parallel instruction sets to the quantum field simultaneously. 236 00:13:05.480 --> 00:13:08.519 And the critical outcome here is that they achieve deterministic 237 00:13:08.519 --> 00:13:10.679 teleportation for multiple quomas. 238 00:13:10.679 --> 00:13:13.240 Could we really need to define deterministic in this operational 239 00:13:13.279 --> 00:13:15.639 context because it's a major distinction. 240 00:13:15.519 --> 00:13:18.519 Right, Because a lot of advanced quantum protocols, especially the 241 00:13:18.519 --> 00:13:22.840 ones using linear optics and single photon detection, they're probabilistic. 242 00:13:23.279 --> 00:13:26.759 They rely on post selection, which means the operation only 243 00:13:26.799 --> 00:13:29.480 actually succeeds a fraction of the time. You have to 244 00:13:29.519 --> 00:13:30.960 throw away all the failed. 245 00:13:30.639 --> 00:13:35.000 Runs, which severely limits your data through put rates. You 246 00:13:35.039 --> 00:13:37.799 can't run a reliable network if the routing only works 247 00:13:37.840 --> 00:13:38.559 ten percent. 248 00:13:38.399 --> 00:13:42.639 Of the time exactly. Deterministic teleportation, on the other hand, 249 00:13:43.000 --> 00:13:46.519 guarantees the success of the protocol for every single execution, 250 00:13:47.200 --> 00:13:52.120 assuming ideal equipment and no catastrophic environmental interference obviously. 251 00:13:51.879 --> 00:13:56.879 And continuous variable teleportation because it uses highly squeezed states 252 00:13:56.919 --> 00:13:59.919 and hamidine detection is inherently deterministic. 253 00:14:00.159 --> 00:14:03.120 It is, and the massive achievement of the Shanksy University 254 00:14:03.120 --> 00:14:07.240 team is that they successfully maintain that deterministic nature while 255 00:14:07.320 --> 00:14:09.399 scaling the protocol up to parallel channels. 256 00:14:09.440 --> 00:14:13.159 Their teleportation of the multiplex sideband QUO modes function reliably 257 00:14:13.200 --> 00:14:16.360 on demand, no probabilistic post selection required, which. 258 00:14:16.200 --> 00:14:18.279 Is a strict prerequisite if you ever want to integrate 259 00:14:18.320 --> 00:14:21.559 this technology into active continuous communication networks. 260 00:14:21.879 --> 00:14:25.519 So they quantified the capacity of this parallel transmission by 261 00:14:25.600 --> 00:14:30.080 teleporting up to five distinct sideband quomodes, and they fit 262 00:14:30.200 --> 00:14:34.120 all five into a highly compressed parameter a twenty four 263 00:14:34.320 --> 00:14:35.480 megahertz bandwidth. 264 00:14:35.799 --> 00:14:39.559 Using such a narrow frequency ban to host five independent 265 00:14:39.720 --> 00:14:44.320 deterministic quantum channels, that demonstrates extreme spectral efficiency. 266 00:14:44.399 --> 00:14:47.919 Plus the methodology has this built in system of dynamic 267 00:14:47.919 --> 00:14:52.120 control variables. It makes it incredibly flexible for network architectures. 268 00:14:52.279 --> 00:14:56.559 Right, the architecture isn't statically locked into teleporting exactly five 269 00:14:56.639 --> 00:14:57.799 quot modes every time. 270 00:14:58.000 --> 00:15:00.159 So how does the dynamic control workm. 271 00:15:00.000 --> 00:15:04.240 Practice the classical phase tuning mechanism. Let's operators selectively dictate 272 00:15:04.279 --> 00:15:07.039 the precise number of quomodes they want to reconstruc during 273 00:15:07.120 --> 00:15:07.799 any given. 274 00:15:07.600 --> 00:15:09.879 Run by altering the specific phase delays. 275 00:15:09.960 --> 00:15:13.080 Yes, by altering the phase delays and the corresponding radio 276 00:15:13.080 --> 00:15:17.039 frequency signals injected into the classical feed forward channel, operators 277 00:15:17.039 --> 00:15:21.039 can dynamically target one, two, three, four, or five sideband frequencies. 278 00:15:21.120 --> 00:15:25.919 It completely bypasses the limitations of a rigid fixed channel system. 279 00:15:25.639 --> 00:15:30.720 Exactly, the ability to dynamically allocate bandwidth just by adjusting 280 00:15:30.759 --> 00:15:35.639 classical control variables, rather than having to physically reconfigure complex 281 00:15:35.759 --> 00:15:39.320 quantum optical hardware that gives you the precise routing capability 282 00:15:39.360 --> 00:15:42.519 you absolutely need for a multi Noode quantum network. 283 00:15:42.600 --> 00:15:46.360 Okay, so having established how they achieved parallel transmission, we 284 00:15:46.480 --> 00:15:50.679 have to transition to the verification protocols because claiming you 285 00:15:50.720 --> 00:15:54.000 transfer to quantum state requires rigorous mathematical proof. 286 00:15:54.279 --> 00:15:56.519 You have to prove the output state is a genuine 287 00:15:56.600 --> 00:16:00.279 reconstruction of the input state, and more importantly, that this 288 00:16:00.320 --> 00:16:05.039 reconstruction could not possibly have been achieved through purely classical means. 289 00:16:04.759 --> 00:16:07.480 And the primary metric for this validation is the fidelity 290 00:16:07.480 --> 00:16:08.759 of the quantum state transfer. 291 00:16:08.919 --> 00:16:12.279 Fidelity is a strict mathematical measure of the overlap between 292 00:16:12.320 --> 00:16:16.240 two quantum states. It quantifies the distinguishability the input state 293 00:16:16.279 --> 00:16:19.279 provided to the sender and the output state retrieved by 294 00:16:19.279 --> 00:16:19.799 the receiver. 295 00:16:20.080 --> 00:16:23.240 Let's get into the math briefly. In the density matrix formalism, 296 00:16:23.399 --> 00:16:24.399 how is it calculated. 297 00:16:24.600 --> 00:16:26.919 It's calculated as the trace of the square root of 298 00:16:26.960 --> 00:16:29.679 the products of the square root of the input density matrix, 299 00:16:30.120 --> 00:16:32.679 the output density matrix and the square root of the 300 00:16:32.759 --> 00:16:33.840 input density matrix. 301 00:16:33.879 --> 00:16:36.799 Again, so a fidelity metric of one point zero or 302 00:16:36.840 --> 00:16:40.399 one hundred percent indicates perfect state transfer, the output is 303 00:16:40.440 --> 00:16:42.440 perfectly identical to the input right, and. 304 00:16:42.399 --> 00:16:45.879 A fidelity of zero point zero indicates completely orthogonal states 305 00:16:46.200 --> 00:16:47.399 with zero overlap. 306 00:16:47.600 --> 00:16:51.240 And the objective of any quantum teleportation experiment is to 307 00:16:51.399 --> 00:16:53.080 maximize that fidelity metric. 308 00:16:53.240 --> 00:16:55.960 And the empirical data published by the Shanksy University team 309 00:16:56.039 --> 00:17:00.240 reported that their simultaneous teleportation of the multiplexed sea side 310 00:17:00.240 --> 00:17:04.119 band coool modes achieved output fidelities of approximately seventy percent 311 00:17:04.400 --> 00:17:05.640 or point seven to zero. 312 00:17:05.559 --> 00:17:09.000 Which sounds good. But to evaluate the true significance of 313 00:17:09.039 --> 00:17:12.480 a point seven zero fidelity metric, you must comprehend the 314 00:17:12.559 --> 00:17:13.640 non cloning limit. 315 00:17:13.880 --> 00:17:17.000 Yes, the non cloning limit serves as the fundamental benchmark 316 00:17:17.119 --> 00:17:19.559 in continuous variable quantum mechanics. 317 00:17:19.079 --> 00:17:22.519 Normalized in nineteen eighty two by physicists Wooters and Zurich. 318 00:17:22.880 --> 00:17:26.279 Right, it's a direct consequence of the linearity and unitarity 319 00:17:26.279 --> 00:17:29.359 of quantum mechanics. It simply states that it is physically 320 00:17:29.400 --> 00:17:33.799 impossible to create an independent, identical copy of an arbitrary, 321 00:17:33.920 --> 00:17:35.359 unknown quantum state. 322 00:17:35.559 --> 00:17:38.160 So how does the non cloning theorem apply to the 323 00:17:38.200 --> 00:17:39.200 measurement process. 324 00:17:39.599 --> 00:17:43.480 It dictates that the measurement process inherently disrupts the quantum system. 325 00:17:44.000 --> 00:17:46.720 If you attempt to replicate a quantum state using a 326 00:17:46.720 --> 00:17:50.359 measure and prepare strategy, meaning you perform a classical measurement 327 00:17:50.440 --> 00:17:53.599 on the input state to extract as much information as possible, 328 00:17:53.960 --> 00:17:56.440 send that classical data, and use it to prepare a 329 00:17:56.480 --> 00:17:58.319 new state at the destination. 330 00:17:58.119 --> 00:18:01.599 You are strictly constrained by the Heisenber uncertainty principle. 331 00:18:01.279 --> 00:18:05.400 Exactly measuring one conjugate variable like the amplitude quadrature introduces 332 00:18:05.480 --> 00:18:08.839 noise and uncertainty into the other conjugate variable, the phase quadrature. 333 00:18:09.160 --> 00:18:13.160 You absolutely cannot simultaneously extract perfect information about both. 334 00:18:13.319 --> 00:18:17.279 Consequently, the newly prepared state will inherently contain a minimum 335 00:18:17.319 --> 00:18:18.799 amount of added noise. 336 00:18:18.720 --> 00:18:21.240 Typically quantified as one unit of vacuum. 337 00:18:20.839 --> 00:18:25.319 Noise, and this unavoidable introduction of noise establishes a strict 338 00:18:25.359 --> 00:18:28.839 mathematical ceiling on the fidelity of any state transfer that 339 00:18:28.920 --> 00:18:34.359 relies purely on classical strategies without utilizing quantum entanglement. 340 00:18:34.000 --> 00:18:37.799 For the teleportation of coherent states in a continuous variable system. 341 00:18:38.200 --> 00:18:42.160 This absolute classical boundary, the non cloning limit, is mathematically 342 00:18:42.160 --> 00:18:45.079 proven to be exactly fifty percent, or a fidelity of 343 00:18:45.160 --> 00:18:45.920 zero point five. 344 00:18:46.079 --> 00:18:49.480 The zero point five threshold is the strict demarcation line 345 00:18:49.519 --> 00:18:53.559 between classical state replication and genuine quantum teleportation. 346 00:18:53.799 --> 00:18:56.240 If an experiment yield to a fidelity equal to or 347 00:18:56.319 --> 00:18:59.559 lower than point five, your results can be entirely explained 348 00:18:59.559 --> 00:19:03.519 by a cloislassical measure and prepare strategy. The protocol has 349 00:19:03.519 --> 00:19:05.400 demonstrated zero quantum. 350 00:19:05.160 --> 00:19:09.440 Advantage, so to definitively prove that the protocol successfully utilized 351 00:19:09.480 --> 00:19:13.240 shared quantum entanglement to bypass the uncertainty principle and teleport 352 00:19:13.240 --> 00:19:17.119 the state. The calculated fidelity must mathematically surpass the point 353 00:19:17.160 --> 00:19:18.440 five threshold. 354 00:19:18.079 --> 00:19:21.079 And this is why the Shanksy University achievement is so profound. 355 00:19:21.400 --> 00:19:24.079 It's not merely that they multiplex five channels. It's that 356 00:19:24.079 --> 00:19:27.799 the empirical data confirms all five teleported cool modes simultaneously 357 00:19:27.799 --> 00:19:30.200 achieve fidelities of approximate lyight point seven. 358 00:19:30.119 --> 00:19:33.799 Zero, systematically exceeding the classical limit point five. 359 00:19:34.079 --> 00:19:38.039 By surpassing this non cloning limit concurrently across all five 360 00:19:38.079 --> 00:19:42.839 frequency channels, the researchers mathematically validated the quantum nature of 361 00:19:42.880 --> 00:19:43.920 the parallel transfer. 362 00:19:44.119 --> 00:19:48.039 They provided definitive proof that quantum entanglement was the actual 363 00:19:48.119 --> 00:19:52.160 operational mechanism preserving the integrity of the state transfer across 364 00:19:52.200 --> 00:19:53.960 the entire multiplex spectrum. 365 00:19:54.039 --> 00:19:57.839 That verification validates the entire methodology. 366 00:19:57.279 --> 00:20:00.559 Which transitions our analysis directly to the empl locations. This 367 00:20:00.599 --> 00:20:04.359 breakthrough holds for a high capacity quantum infrastructure. 368 00:20:03.720 --> 00:20:08.599 Because the architectural requirements for scaling entanglement based communication links 369 00:20:08.839 --> 00:20:10.519 are fundamentally altered. 370 00:20:10.160 --> 00:20:13.640 Now right, the traditional approach to increasing channel capacity and 371 00:20:13.759 --> 00:20:18.079 quantum networks meant you had to linearly scale physical resources. 372 00:20:18.119 --> 00:20:21.680 If you wanted ten independent quantum channels, you needed. 373 00:20:21.480 --> 00:20:26.000 Ten distinct entanglement generation sources, ten sets of it afarometers, 374 00:20:26.440 --> 00:20:28.799 twenty separate hamidine detectors. 375 00:20:28.519 --> 00:20:32.160 The physical footprint, the complexity of stabilizing all those lasers, 376 00:20:32.480 --> 00:20:36.839 the power consumption. It all scaled proportionally with the required bandwidth, but. 377 00:20:36.839 --> 00:20:41.799 The implementation of phase controlled frequency multiplexing completely eliminates that 378 00:20:41.920 --> 00:20:43.359 linear scaling dependency. 379 00:20:43.759 --> 00:20:47.200 You can analyze the information density optimization here just by 380 00:20:47.279 --> 00:20:49.799 looking at how they pack more quantum information into a 381 00:20:49.799 --> 00:20:50.880 singular physical system. 382 00:20:51.000 --> 00:20:54.640 By utilizing multiple side bands on a single optical carrier, 383 00:20:55.200 --> 00:20:59.680 researchers can exploit the massive frequency bandwidth inherent in optical fields. 384 00:21:00.079 --> 00:21:05.400 The shared entanglement resource the multipartite continuous variable entangled state 385 00:21:05.440 --> 00:21:10.240 that's generated by a single optical parametric amplifier. It's effectively 386 00:21:10.319 --> 00:21:12.279 partition across the frequency domain. 387 00:21:12.559 --> 00:21:16.839 The primary architectural advantage is the direct elimination of redundant 388 00:21:16.839 --> 00:21:19.920 hardware setups. You can have a single transmitting node and 389 00:21:19.960 --> 00:21:23.319 a single receiving node connected by one unified quantum channel 390 00:21:23.640 --> 00:21:27.119 processing multiple independent quantum data streams simultaneously. 391 00:21:27.759 --> 00:21:30.839 The capacity of the network scales simply by adding frequency 392 00:21:30.920 --> 00:21:35.279 channels in the control software rather than building physical hardware, which. 393 00:21:35.119 --> 00:21:40.880 Directly mirrors the historical evolution of classical telecommunications infrastructure, and honestly, 394 00:21:41.279 --> 00:21:45.079 it provides a mathematically viable pathway toward constructing a global 395 00:21:45.160 --> 00:21:46.559 quantum Internet. 396 00:21:46.200 --> 00:21:50.279 An Internet capable of supporting high volume, secure data transmission, 397 00:21:50.599 --> 00:21:53.799 quantum key distribution, distributed quantum computing. 398 00:21:53.880 --> 00:21:55.440 The applications are immense. 399 00:21:55.240 --> 00:21:59.680 And speaking of immense applications, you have to objectively contextualize 400 00:21:59.799 --> 00:22:04.119 this societal and technological trajectories that are often extrapolated from 401 00:22:04.160 --> 00:22:06.920