Scalability and economics

48:39Okay. This is where the the this is where the startup pitch decks collide with reality. They collide with the laws of thermodynamics and the laws of economics which are not real laws. Which is why the economics Nobel Prize is not a real Nobel Prize. Okay. Had to say it. But when someone says we've got 100 cubits today and our road map is that we're going to have a million cubits um in 5 years. Okay. Really? Are you? >> Are you? >> Um I don't believe you. >> Yeah. Yeah. Yeah, you're there should be some salt >> in that. >> Um, so first of all, how much cooling are you going to need? >> That's a big question that you should ask because quantum things are finicky.

49:22>> Okay. And you have to talk about the biggest, loudest, and most obnoxious problem in the universe when it comes to maintaining quantum information and that is heat. So heat is the amount of jiggle and the amount of entropy um sorry the amount of energy in any degree of freedom of a system. For example um the heat in this room right now the the the room is about 70° Fahrenheit. So I don't know let's say um 200 like 300 no like 290 290 Kelvin above absolute zero. So 290° C above absolute zero. What that means is that the u molecules in our room have um an average amount of kinetic energy that is proportional to

50:05270 the number. >> Yeah. >> Multiplied by something called Boltzman's constant. Okay. And the the Boltzman's constant is literally just a um it's like a a a tally trick for us to convert from temperature to energy. Okay. If if I were to if a physicist were to invent a new society, we would be measuring temperature and energy with the same scale. There would not be a Kelvin and a jewel. There would just be uh FFP. >> That's what we call >> which represents it both across both. >> Yeah. Because both things are the same thing really. Temperature is is the amount of energy on average in every single degree of freedom. Now in

50:46classical computers, this doesn't matter so much. Okay. Um, unless you get up to like 100 degrees Celsius, 400 Kelvin. I mean, you know, we did cover a recent paper where it got all the way up to a,000 Kelvin. >> Yes. Which is >> and it was fine. >> It was fine. >> But that was a that was a weird um meister made out of graphine >> and tungsten and all this other stuff. But like our normal computer like it's going to fail, right? Because the there's going to be so much movement of electrons and so much jiggling of the atoms that it's going to destroy whatever computation is happening. Yep. >> Right. Yep. Now, but that's at like 100° C, 400 Kelvin. A cubit is incredibly delicate, though. Okay. The energy

51:26difference between a cubit's zero and its one state is microscopic. We're [clears throat] we're measuring this stuff in terms of electron volts, which is the amount of energy that it takes to move an electron up one volt, a single electron, right? It's it's minuscule. And if the ambient energy of the environment >> is larger than the energy gap of your cubit, right? Imagine, imagine I've got two states, my zero and my one, which is the cubit, um, whatever thingy, whether it's superconducting, and we'll get into what these states are, but imagine I've got a two-state system where the system can be in this spot or it can be in another spot. And the energy difference to jump from one to the other is some amount,

52:06but the amount of energy in the environment that's knocking you around, >> right, >> is larger than that amount. Well, then if I prepared, right, I want I'd like to prepare my cubid in the zero state. Well, pretty soon it's just going to go into a mix of the two. It's going to bounce around between the two, right? Um, it reminds me of um like imagine for example, you're in a car and you've got like a one of those beach balls, Earth beach balls in the passenger seat >> as opposed to those Mars Mars beach balls. >> Yeah. Yeah. Yeah. No, I I ain't going to Mars. I'm trying I'm trying to get Earth beach ball and the north pole is pointing north in your passenger seat and the south pole is pointing south in your passenger seat. If you're on a pristine road in I don't know like

52:48Switzerland, right? And there's no curves and you're just going straight that beach ball once you prepare it in the zero and one. So in the north pole facing up, right? The earth looks like this the earth and I just keep driving because the road is so smooth the the beach ball is going to stay in that in that right. But if I if if I go into a New York City ridden pothole street, which Mom Donnie fixed, good for [laughter] him, by the way. >> Good for him. >> Good for Good for Mom Donnie that he fixed all those potholes. But before the fixing of the potholes, if I was driving down a New York street, >> the road would be bumpy [snorts] and the bumps would impart an energy into my beach ball. >> Yeah.

53:28>> Right. That would start turning it. >> And there's some amount of energy that's required to keep this thing upright. But if I'm bumping enough, >> then this thing is can be in any way which >> I need to isolate thermal noise from my system. >> And this goes back to the how good is your cooling? Because basically you're saying how good is the suspension in your car when you hit a pothole? >> Exactly. Right. Is it really nice where you don't need a little and get rid of the jiggle for the beach ball or you know are you in a you know >> are you in a Jeep? No, that's No, where you feel where you want to feel every like I mean maybe that's part of the

54:08point of the Jeep, right? But like a Jeep would not make a good uh cubit controller, right? A Rolls-Royce might or Bentley might, >> right? Because that's what they optimize for is a smooth luxury uh riding experience. >> Yeah. And so for for a lot of these solid state cubits, you're operate that means you got to operate at 10 millichelvin above absolute zero, which is colder than outer space. Outer space is at like 3 Kelvin. So this is an order of magnitude if not more colder than outside like outer space >> and this is where you have to operate the computer. So it's like okay you're going to create this environment at scale to get a million cubits and you're going to do it at an order of magnitude cooler than deep space. >> And [clears throat] then the other challenge is in order to operate my

54:49cubit I got to send in electricity >> or stuff right to to like move it around like whether it's lasers or we'll get into that. Well, that better not heat up the the computer, >> right? >> Right. So, so that's a challenge that is going to affect how well you can scale stuff. >> Yes. >> Okay. And if you've ever seen a picture of a quantum computer, you've probably seen like those giant steampunk golden chandeliers um with the wires coming down and things like that. Yes. >> Um, all of that is the the well the the infrastructure of a lot of it is the dilution refrigerator where you're you're using helium and helium a mixture of helium 3 and helium 4 to get down to

55:31that base temperature of tens of millichelvin. >> Okay. >> Yeah. Who who knew being a quantum computer architect was uh similar to being a butcher who needs to keep their beef frozen. >> Yeah. Yeah. Effectively >> managing refriger managing refrigeration. Dude, you I have so many horror stories about about dilution refrigerators and that is for another time. Let's just say um but >> the point is you got to keep it cold. >> Okay. >> So, um that's why we got to freeze these things >> to that to that cold and and it better be frozen, >> which is non trivial like the big nonrival right? >> Okay. And that's going to that's going to come in later. Okay. The other thing is how big is the thing going to be? Yeah. >> Right. The whole if I want a million cubits, how big is it going to be?

56:12That's a question that you need to ask. Um, how much power are you going to need? If you got a bunch of fridges, you're going to need a bunch of power. You're going to need a bunch of helium. There's not a lot of helium 3 out there. There's a lot of helium 4. There's not a lot of helium 3 out there in the world. >> And we're not yet bringing it back from the lunar surface to Earth. Exactly. Which is also expensive. >> Yeah. That would also be right that that's not a solution for scalability. Correct. >> Right. At that point, just put a quantum computer on the moon. Are you serious? We're seeing the same issue with AI where it's like oh we want to do you know whatever all but it's like okay but the power power is the limiting factor more than compute is >> and it's the same issue >> exactly and then finally it would be

56:53like how are you going to manufacture this thing at scale >> okay so so those are the three criteria cubit quality cubit control and then scalability and economics okay and with that now let's get into our first leading modality okay this would be our Manchester city, let's say. Okay, so