The word quantum computer is a little bit misleading because it sounds like a computer and when people think of computer, they think of a phone or a laptop. The truth is the phone and the laptop and even a very powerful supercomputer all operate according to the same fundamental rules and a quantum computer is fundamentally different. The classical bit stores information as a zero or one and a quantum bit can be both zero and one. At the same time, if you have two quantum bits, then there are four possible states that you can put in superposition with three qubits it’s, eight four qubits at 16, but grows exponentially. The nice thing about quantum supremacy is that this is a very well defined engineering. Milestone in a nutshell, what we’re trying to do is we’re trying to so that experimental quantum computers can surpass the best super computers in the world to actually demonstrate quantum supremacy. We have these three steps. First, pick a circuit, second run it on the quantum computer. Third simulate what the quantum computer is doing on a classical computer. We gradually increase the complexity of that circuit. At some point, it becomes completely impossible for the classical computer to keep up. Then we say: we’ve achieved quantum supremacy, Music. We started building together in the quantum chips to do this experiment and then the evolution of the devices with more and more qubits and more and more complexity, it’s very much an iterative process.

A lot of the work that we put in was not just these chips, but it’s also the infrastructure that you need to drive those chips, the cryostats that we install them in all of the control, electronics software. All of this stuff is needed and it all has to be developed. When the experiment started, we were getting data from the experimentalist. We saw initially a beautiful straight line, corresponding to our predictions. Then right before we hit supremacy, they it dropped much faster and it fell below the threshold where it needed to be and there’s nothing. We can do because we don’t know how to analyze past that so everyone’s like oh we’re screwed, because it’s just it’s getting really really bad at a large number of qubits it’s like well, maybe there’s, some really complex interaction between all the qubits. It turned out that the reason was rather benign. We calibrated a little bit better and then this problem disappeared. So there wasn’t like a oh, we did it. I think we crossed it and then it wasn’t clear that we crossed it. So we crossed it a little bit further. It took me like a day to realize like hold on you know. This is actually experimental data, it’s kind of amazing to see you know how. Well the theory works. The processes that achieved quantum supremacy is called the sycamore processor and it’s parallel processing, two to the 53 states, which is 10 million billion, and thus that enormous amount of parallel processing is what gives it the power.

When we run small chunks of the computation is the largest supercomputer in the world, our estimate is that it will take thousands of years to complete the full computation technologies are born. This way, let’s say the space age started with a satellite orbiting earth and it was not doing much. It was just beeping. The big technical achievement of quantum supremacy was really dependent on all this young talent, who’s kind of taken this and gotten it to work at a very technologically capable level. We have reached a new computational capability. There are certain computations, the only place in the world where you can compute those things is here in our data center at google, santa barbara for the first time we’re, showing that we can solve a problem that is just infeasible to do on the biggest computers ever Made by civilization and what’s exciting is now we’re ready to turn this over to the world and say let’s figure out what we can do with this. The thing that excites me most is building a useful quantum computer when we can give a researcher a tool that is, unlike any other and say great figure out something cool to do with it.