字幕表 動画を再生する 英語字幕をプリント Well, brief mentions in other videos about the Q-word, *Laughs* you know, the magic computers that are going to break all encryption and beat everyone at their own game and be the next big thing and be on all our smartphones. Should we put some reality on this? Where are we at with quantum computing? I Work at a company called Righetti computing. We're a company in Berkeley, California And we build quantum computers from the ground up. We do the silicon fabrication all the way up to how we program the machines I in particular Think a lot about how we program the machines how we interface with it at some point Somebody has to type something into a keyboard to make it do something and that's mostly where I think about things quantum computers Really should be thought of as a way to Augment our existing compute infrastructure exists in computers solve problems, and that's not going away there. They will continue to solve good problems So a quantum computer really should be thought of as a is a special-purpose machine that can solve certain problems a lot better Than existing computers can solve them. In fact, I think thinking of it like a GPU is is pretty fruitful that GPUs are, are, they are computers in a sense. But really they're they're better thought of as like a coprocessor to your main computer. They GPUs are extremely good at solving a variety of problems you could sort of Wrangle a GPU to solve any problem you want to but it's you know regular computers are good at that so quantum computers I think of as like on the side Unfortunately current quantum computers are gigantic. They're they you know, they're like the old computers like the ENIAC they fill a room But nonetheless you you hook your computer up to this and it does separate problem-solving as a company We build these quantum computers and deploy them there. They're Accessible right now on the cloud. There's something that I on my laptop anywhere Actually, I don't need any special interface can connect up to them and do computations with them And we're at a point now where? the fundamental unit of resource of a quantum computer just as we take regular computers and think about them in terms of bits and gigabytes and so on on a quantum computer These are measured in qubits, which are very special because every time you add a qubit You're you're doubling the capacity of the computer in some way. So Last year, we released a machine that has around eight qubits. And now the current machine we have is about nineteen qubits so it's not that we Approximately just doubled the qubit because each qubit itself is doubling so you have to think of that number of doublings each time from eight to nineteen problems that deal with lots of interactions or lots of Possibilities so to speak are where quantum computer sort of shine so one big area of application is in quantum computing is the simulation of molecules molecules are are made up of a bunch of atoms and each of these atoms is is Applying a force to the other atoms they're pushing and pulling each other and they're just lots of ways in which the atoms interact with one another and a quantum computer is extremely good at Keeping track of all that and dealing with that in a very efficient way that classical computers which are normal computers Don't deal with quite as well Likewise other types of problems like optimization which in mathematics means kind of finding the best or worst possible solution to a problem Quantum computers are showing a lot of promise and with that said though There's one point I want to make which is sort of in popular science people think that quantum computers just sort of try every possibility At the same time you get all these sort of kooky Interpretations of multiple universes and so on and quantum computers, don't do that. They do not try every possibility at the same time But the second point is that applications of quantum computing is a very active field of research quantum computers currently are They're called noisy quantum computers. They they sort of act like analog devices not digital devices And so there's all this a little bits of error and little bits of noise that come into the system and so it's an active field of research to see what Algorithms and what problems are very robust to this noise and it turns out that this molecular simulation is an example of a problem That's very robust to noise Whereas what? You might heard of like Shor's algorithm and factoring and breaking encryption are not robust annoys at all They're very difficult to to do so that's a very active field of research both at the company that I work at As well as more broadly the community the sort of room size computers are sort of where we're at the way in which these computers have been constructed is Using sort of off-the-shelf components that have not been specially made for the construction of that machine in general So you find generally with these quantum computers you find big racks of analog electronics these electronics that that have existed for other applications and so It's definitely not at a point where we've we've sort of custom fabricated the entirety of the machine I'm not just talking about the quantum chip itself But the thing that the quantum chip is housed in the electronics that go with the quantum chip, etc, etc We're only just starting We just in general as a in the field of quantum computation are only just starting to make like customized electronics and the like for these systems The other aspect of this is that just like the ENIAC for example Which had vacuum tubes that burnt out and you had to go replace them Literal bugs getting in there and so on neither of those things happen with quantum computers But what does happen is that the system in general isn't shown to be stable across, you know? Five or ten years and just hasn't existed that long And so components are are often swapped out often changed It's not robust to changes in the environment like if somebody walks by with a big magnet the whole thing kind of goes awry, so it's a really sort of Finicky machine not unlike the early computers like the ENIAC and so on How far are we off quantum smartphones? Yeah, that is that is really really far away because we need to cool these chips down to like the same temperature or colder than The temperature of outer space so you need big refrigerators as they're called Not going to happen for a good while The interesting thing though is When we have multiple qubits, and this is really where the power of quantum computation happens We can actually think of it sort of simply Diagrammatically that if qubits if I just represent them sort of as a circle here, maybe we have three the idea Is that these qubits can interact this guy can interact with this guy?
B1 中級 量子コンピューティングの現状 - コンピュータマニア (Current State of Quantum Computing - Computerphile) 14 2 林宜悉 に公開 2021 年 01 月 14 日 シェア シェア 保存 報告 動画の中の単語