| Intro Quantum computers are one of the three most impactful future technologies in the world… But not even their most die-hard fans believed quantum chips could be scaled for any meaningful, practical application, let alone to be mass-produced any earlier than in 10 or 20 years… Until now!A major player in the field of quantum computing designed, built, and tested the first scalable, production-ready quantum computer chip based on photonics and partnered with one of the world’s largest chip manufacturers to make the new photonic quantum chips AT SCALE.We are at a historic moment, guys.This new invention could be for quantum computers what the transistor was to the desktop computer.In today’s video, we’ll dive into how photonic quantum computers work, and how they finally solve quantum computing’s biggest hurdles.Are home quantum computers around the corner? Let’s figure it out together. I’m Ricky, and this is Two Bit da Vinci. |
| The Quantum Hype A lot of people talk about AI as the next game-changer, and I get it.AI is already changing the world as we know it. It has changed how we work, learn, the things we can do, and have made us even question our significance in the world.AI has touched us all in more ways than we realize, becoming one of the few technologies that have so far managed to live up to the hype. But the real revolution will be quantum computing.Think about it: the internet, AI, blockchain, EVs, smart factories, they all run on computers.Quantum computing has the potential to revolutionize how computers work, so they’ll revolutionize AI, EVs, Gaming, and almost everything you can think of.But there has always been one big problem:Unlike AI, quantum computers haven’t been able to deliver on their promise of quantum supremacy, that is, their ability to perform certain tasks exponentially faster than classical computers. The problems behind reaching quantum supremacyThe problem is that quantum processors can sometimes give wrong answers.They’re prone to errors, and that isn’t good.I’ll explain why in a minute, but for now just know that those errors are a part of their quantum nature, so it’s impossible to avoid them.But there’s a workaround:Almost three decades ago, two researchers came up with a solution.Peter Shor and Andrew Steane independently published two different Quantum Correction Codes that combined several qubits to protect a single qubit against error.So, if you have a large enough quantum computer, you dramatically reduce the error rate to a point that’s “acceptable” for quantum computations.But that’s where the quantum computers’ second Aquiles heel comes in:It’s estimated that you need at least 1 to 10 million qubits for a practical quantum computer.But quantum computers are very hard to scale.So the core problem is scaling. Find a way to scale a quantum computer, and you solve both problems at once. The thing is, most quantum computers today need to be kept at freezing temperatures of just a few milikelvin, which is way colder than interstellar space.Scaling that is very hard, expensive, and impractical. But, as you can probably imagine by now, someone cracked the code!That someone is a company called PsiQuantum.What are quantum computers and how do they work?Ok, so by now you may be wondering what on Earth is a Qubit and how this all works.And we definitely have to put on our engineering hats on for a minute to explain that, because it’s the only way we can understand just how ijmportant PsiQuantum’s new approach is.You can think of a classical computer like your laptop or smartphone as a giant collection of millions of tiny little switches called transistors.Each transistor is like a little switch that can only be either ON or OFF at any given time.In encodes information in the form of a zero, when it’s OFF, or a one, when it’s ON.This zero or one is what we call a classical bit of information.This entire video is literally written on the computer as a unique sequence of bits, or zeros and ones! A quantum computer works with quantum bits or qubits which are very different:A qubit can be ONE, ZERO, or any combination of both at the same time.This is called quantum superposition and is a unique property of quantum systems, (and a weird one at that, if you ask me.)Onother weird thing about qubits is that, though thy exists in this superposition of states, that state collapses into a definite ONE or a ZERO when you measure it with a certain probability.It’s like when you toss a coin and it spins in the air. The coin will ultimately land on HEADS (ONE) or TAILS (ZERO), but as it’s spinning in the air, it’s essentially both at the same time.This is at the hart of Schrodinger’s cat paradox: put a cat in a box with a bit of poison and seal it in, and the cat may be alive or dead. For all practical applications it’s both alive and dead, but you won’t know for sure until you open the box and look at it.Another difference between bits and qubits is how you make them:Instead of using ON/OFF switches like transistors or old vacuum tubes, the “ones” and “zeros” in a qubit usually represents the state of some quantum property like magnetic spin or polarization.This means you can make different types of qubits. Until very recently, the only real contenders wereSuperconductingSemiconductingNeutral atomAnd traped ion qubits.And now, thanks to PsiQuantum’s new approach, we have photonic quantum qubits. But I’ll get back to that those in a second because there’s something else we need to cover first. You see, the weirdness of qubits doesn’t end here.Quantum computers also leverage a phenomenon called quantum parallelism.Since qubits can exist in superpositions of states representing multiple values at once, they hold more information than a normal bit, and a quantum computer can perform operations on all these potential values simultaneously.This means quantum computers can potentially explore multiple solutions to a problem simultaneously. It was hard for me to understand how exactly this works at first so I dug a little deeper.It has to do with the wave-like properties of quantum systems.Here’s how that works:The state of a quantum system like a qubit is given by something called a wave function.So, like a wave, the qubit’s state can go from a through, representing a zero, to a peak, representing a one, and every value in between. That’s the superposition of states.Now, just like your normal sound wave or the ripples in a pond, those wave functions can interact with each other through something called quantum interference.(get some still water like your full hot tub for this analogy)Ok, so imagine this is a qubit and the ripples I’m making are its wave function (your finger tapping in one spot on the surface).And now let’s add another qubit here (start tapping somewhere else in the water at the same speed)See what happens to the waves when they interact?In some parts, where the peaks of the waves coincide the wave functions will add up and amplify, which is constructive interference. (you can maybe slow down the footage and zoom in at a point where there are strong peaks and throughs in the water).And in others, they’ll cancel out, which is destructive interference (you can zoom in at a point where the water doesn’t rise).If you add more qubits, the pattern becomes more complex with large peaks in some areas and smaller ones in others, etc..What a quantum computer’s algorithm does is manipulate the qubits in a way that uses constructive interference to amplify the right answer to a problem.And destructive interference to suppress the wrong answers.So you end up with a pattern like this where the tallest peak represents the optimal answer.What’s cool about this is that this whole interference pattern appears right away when you run the algorithm on the input qubits.So you get a snapshot of all possible solutions without having to build the pattern by evaluating a function for each value of a bit, one by one.This is just an analogy, of course, but it gets the idea across.Finally, there’s the issue of entanglement.The laws of thermodynamics let us create qubits whose states are strongly correlated.This is called entanglement.That means that the state of one entangled qubit immediately determines the state of the entangled pair.This takes quantum parallelism to a whole new level:If you entangle, say, n qubits, running an algorithm on just one of them is like running it on all of them.This makes sprocessing speed increase exponentially with the power of n, whereas classical compute power only increases linearly.For example, if you have one bit and you increase it to 2 or 3, your processing power will double or triple.But if you have one qubit and you increase it to two or three entangled qubits, your processing power multiplies by 4 or 8.Imagine how that scales if you have 100 or a million qubits.This makes some calculations exponentially faster than with a classical computer, because it can try all solutions in parallel, or simultaneously.Think of it like searching a maze. A classical computer would try each path one at a time, but a quantum computer with entangled qubits in superposition can explore multiple paths simultaneously. |
| The problem with quantum computing So, quantum computers are powerful and could change the world as we know it.What’s the holdup?Current quantum processors have limited qubit counts, typically ranging from tens to a few hundred qubits. It’s very hard to scale the number of qubits.The record-holder is IBM’s Condor processor, which has 1,121 qubits. But it’s estimated that for error correction, we need at least a million qubits.Most qubits requre cryogenic temperatures that are only 10 or 15 millikelvin. That’s hundreds of times colder than spase!This is why some people don’t think quantum computers will ever be scaled to practical applications, and most don’t think it will only happen in the next 20 years. |
| Enter PsiQuantum This startup founded in 2016 has an innovative approach to quantum computing:They decided to use photons, the particles that make up light, instead of electrons to make their qubits.This is a field called photonic quantum computing, and it offerse several advantages: Scalability: Photonic qubits are easier to scale than other qubit types. They can be manufactured using existing semiconductor fabrication techniques, allowing for hundreds of qubits on a single chip.Room Temperature Operation: Unlike superconducting or trapped ion qubits, photonic qubits don’t require extreme cooling, simplifying the infrastructure and reducing costs.Error Correction: PsiQuantum’s architecture incorporates a robust error correction scheme based on the Gottesman-Kitaev-Preskill (GKP) code, designed specifically for photonic systems. How do you turn photons into qubits? But how do they turn photons into qubits? It took me a while to understand how that works, but this is what I found:You need three things to make a qubit:You need a system that can be in a state of one and zero, but also any superposition of those states.You also need to be able to create entangled qubits.You need qubits to interact with each other through quantum interference to enable quantum algorithms that enhance correct solutions through constructive interference and suppress wrong answers through destructive interference.Light ticks all of those boxes.In the simplest case, you can make photonic qubit’s states be “There” and “Not there”.The way this works is by splitting a beam of light into two separate paths, one of them encodes a digital “ONE” when the photon is detected in that path (it’s “THERE”), and when it’s detected in the other path (so it’s “NOT THERE” in the first path), it encodes a digital “ZERO”.The crazy thing about this is that even a single photon that hits a beam splitter will split between the two paths and be in both paths at the same time.I know this sounds weird, but it’s because light is a wave:Imagine you have this wave coming here from the left, and we put this board here with two slots in the way.Notice how the original wave now splits into two separate waves. However, it’s still actually the same wave.That’s how you get the superposition of states using a single photon and a beam splitter.The photon is simultaneously in both paths at the same time. You can also encode qubit states with photons using other properties like polarization where one state is “vertically polarized” and the other is “Horizontally polarized.”This is what PsiQuantum uses: Path-encoded photonic qubits. Light can have any polarization in between vertical and horizontal or even have all polarizations at once, like sunlight, which is the same as saying it’s not poalrized at all.So, photons can have a superposition of polarization states as well. The other property of photons that make them work as qubits is that you can drive a photon through a non-linear crystal and it’ll split into two lower-energy photons that are entangled.Also, since light is made up of electromagnetic waves, photons can interfere with one another when those waves interact. So, you can create entangled photons with superpositions of “zero” and “one” states and photons show quantum interference: Those are the three hallmarks of a qubit. The best thing about photonic qubits is that, Unlike trapped ion or superconducting circuit qubits, you can make qubits out of photons at room temperature.However, you also need to detect those single photos, and the detector needs to be chilled down to 4K so its noise doesn’t drown out the single photon hitting it. Modular Architecture: But the very best thing about this approach is its scalability.PsiQuantum’s design involves modular quantum computing units that can be interconnected to create larger, more powerful systems. This approach allows for incremental scaling and flexibility in building quantum computers of varying sizes and capabilities. A Focus on Real-World Applications: PsiQuantum is not just focused on building the biggest or most complex quantum computer. They aim to develop a machine that can solve real-world problems in areas like drug discovery, materials science, and finance. Their approach emphasizes practical applications and delivering value to users. PsiQuantum’s Approach in a Nutshell PsiQuantum’s unique combination of photonics, scalable manufacturing, error correction, modular architecture, and a focus on real-world applications positions them as a frontrunner in the race to develop practical and commercially viable quantum computers. While challenges remain, their innovative approach offers a promising path towards overcoming the key drawbacks of quantum computing and ushering in a new era of technological advancement. |
| How PsiQuantum’s chip works PsiQuantum’s chip is a marvel of miniaturization. Imagine a bustling factory where photons, particles of light, are created, guided through intricate pathways, and precisely measured. This entire factory fits onto a tiny chip, smaller than your fingernail.This is a HUGE departure from traditional quantum setups, which often look like something out of a sci-fi movie – tables full of lasers, mirrors, and bulky detectors. PsiQuantum’s approach is sleek, efficient, and most importantly, scalable.But overall, the best part about this story is that they have a clear deadline for the first commercial utility-scale quantum computer in the world. That’s something no one else can boast.PsiQuantum signed a deal with the Australian Government to build the first quantum computer in Birsbane no later than 2029.The computer will cost almost $700 million and will be pretty similar to a modern data center: a large warehouse full of modular photonic quantum chips encased in cryogenic baths, plus a separate building just for the cryo generation.And who’s helping them build it? None other than GlobalFoundries, the THIRD largest chip manufacturer in the world! They’re the experts in photonics, the technology behind fiber optic internet, and they’re bringing that expertise to quantum computing. |
| GLOBALFOUNDRIES: THE SILICON SAVIOR PsiQuantum’s partnership with GlobalFoundries was a master stroke of genius. It means PsiQuantum can leverage the power of high-volume semiconductor manufacturing, something ono other company can boast.They can build hundreds or even thousands of these chips at once, just like we do with regular computer chips. That’s the secret to scaling up quantum computers to the size and power we need.GlobalFoundries might not be a household name, but they’re a major player in the chip industry. They’ve been overshadowed by giants like TSMC, but quantum computing could be their chance to leapfrog the competition. Remember how the U.S. used to be the undisputed king of chip manufacturing? Then, Texas Instruments missed out on the foundry model that Morris Chang pioneered with TSMC. Now, most of our chips are made overseas. This partnership with PsiQuantum could bring chip supremacy back to the U.S. If they succeed in mass-producing quantum chips, it would be a massive win for the American tech industry and a huge boost to national security. |
| THE PROMISE & THE PERIL Let’s be real: quantum computers are NOT about to replace your laptop. But they WILL revolutionize industries in ways we’re just starting to grasp. Think about it: Drug Discovery: Simulating complex molecules to design new life-saving drugs.Materials Science: Creating materials with properties we never thought possible, from superconductors to ultra-strong alloys.Climate Modeling: Running incredibly detailed simulations to understand and combat climate change.Artificial Intelligence: Unleashing AI capabilities beyond our wildest dreams.Now, let’s address the elephant in the room: Quantum computers WON’T magically solve every problem overnight. They’re not going to instantly break all encryption (though they could certainly make some current methods obsolete). And they won’t replace your trusty smartphone for checking social media. This is a long-term game, folks. |
| CHALLENGES AHEAD PsiQuantum has a clear roadmap, but challenges remain. Error correction is still a major hurdle, and complex tasks will require a tremendous number of photons. Cost is another big factor. The first commercially viable quantum computer could cost hundreds of millions of dollars. But remember, the first computers were also massive and expensive. With time, technology tends to get smaller, cheaper, and more powerful. We’re still in the early days of quantum computing, and it’s an exciting time to be a part of this technological revolution. |
