Quantum computers theoretically can prove more powerful than any supercomputer, and now scientists calculate just what quantum computers need to attain such "quantum supremacy," and whether or not Google achieved it with their claims last year.
Superposition lets one qubit perform two calculations at once, and if two qubits are linked through a quantum effect known as entanglement, they can help perform 2^2 or four calculations simultaneously; three qubits, 2^3 or eight calculations; and so on. In principle, a quantum computer with 300 qubits could perform more calculations in an instant than there are atoms in the visible universe.
It remains controversial how many qubits are needed to achieve quantum supremacy over standard computers. Last year, Google claimed to achieve quantum supremacy with just 53 qubits, performing a calculation in 200 seconds that the company estimated would take the world's most powerful supercomputer 10,000 years, but IBM researchers argued in a blog post "that an ideal simulation of the same task can be performed on a classical system in 2.5 days and with far greater fidelity."
To see what quantum supremacy might actually demand, researchers analyzed three different ways quantum circuits that might solve problems conventional computers theoretically find intractable. Instantaneous Quantum Polynomial-Time (IQP) circuits are an especially simple way to connect qubits into quantum circuits. Quantum Approximate Optimization Algorithm (QAOA) circuits are more advanced, using qubits to find good solutions to optimization problems. Finally, boson sampling circuits use photons instead of qubits, analyzing the paths such photons take after interacting with one another.
Assuming these quantum circuits were competing against supercomputers capable of up to a quintillion (1018) floating-point operations per second (FLOPS), the researchers calculated that quantum supremacy could be reached with 208 qubits with IQP circuits, 420 qubits with QAOA circuits and 98 photons with boson sampling circuits.
How Many Qubits Are Needed For Quantum Supremacy?
[Journal Reference]: Quantum Journal
(Score: 0) by Anonymous Coward on Friday May 22 2020, @12:47AM (1 child)
Duh.
(Score: 0) by Anonymous Coward on Friday May 22 2020, @01:02AM
Nah, we need to know what size pyramid table we're dealing with [battlestarwikiclone.org]
(Score: 2) by TheGratefulNet on Friday May 22 2020, @01:09AM (6 children)
I'm not an expert, but I have been reading up a lot on quantum physics, with lots of time on my hands (lol) these days.
quantum computing is nothing like 'normal' computer. you don't translate normal linear code, you don't 'run programs' in the conventional sense and the problem sets you can 'solve' are very different from regular 'apps'.
I'm not sure what they are trying to say. probably nothing.
quantum is quantum. I don't see much overlap with standard computing, but would like to hear from those that know a bit more.
(coolest thing I've read about quantum encryption is the 'read detection' bit; and again, that has nothing at all to do with regular processing; but it does make passing keys in 'plaintext' 100% secure and I thought that concept was cool as can be)
"It is now safe to switch off your computer."
(Score: 4, Interesting) by stormwyrm on Friday May 22 2020, @02:45AM (4 children)
Numquam ponenda est pluralitas sine necessitate.
(Score: 4, Interesting) by Anonymous Coward on Friday May 22 2020, @06:50AM (2 children)
This is not quantum supremacy. Quantum supremacy is well defined. It is when a quantum computer is capable of solving any well defined problem that a classical machine can not [practically] solve. This is an important distinction because you tackle problems differently with quantum vs classical machines. Classical machines obviously don't factor numbers using a simulated Shor's Algorithm [wikipedia.org]. They use e.g. a quadratic sieve. So you need to actually be able to put those qubits to use in a productive way, and that's a lot harder!
Which hits on the second point, and one you hit on though indirectly. It's only for certain esoteric tasks quantum computers can even *possibly* end up being more powerful than any normal computer. The domain of these problem sets is highly restricted into problems that can be translated into a 'quantum domain'. And that is a *very* tiny set of all problems. For let's say 99.9999999999% of purposes, classical computers will reign supreme. So why are governments and companies pouring billions of dollars into quantum machines? It's just the Enigma Project 2.0. The aforementioned Shor's Algorithm could potentially render all contemporary (and past) encryption completely moot. And the NSA has exabytes (if not zettabytes by now) of encrypted data just sitting around gathering dust.
Whoever cracks encryption first stands to gain a major tactical advantage against the rest of the world, especially as we, for whatever reason, do not seem to be in any rush to move to algorithms more resistant to quantum attacks. You will never have something like personal quantum computers because they'd be useless for nearly all practical purposes.
(Score: 4, Insightful) by DrkShadow on Friday May 22 2020, @10:02AM
Anonymous Coward, of Soylentnews, circa 2020.
Thomas J. of I.B.M., circa 1943, The Yale Book of Quotations quotes.
(Score: 3, Insightful) by sjames on Friday May 22 2020, @11:57PM
That's what I found so annoying about the flurry of press releases this year. The quantum computers didn't do any meaningful computation (open question, CAN they?) and the comparison was assuming that the conventional supercomputer would be emulating the quantum computer.
Of course, they also conveniently ignored the considerable setup time for the quantum run.
(Score: 2) by PiMuNu on Friday May 22 2020, @12:55PM
Sounds like there are two problems:
1. When can a "quantum computer" become impossibly complex to model using a "classical computer"
2. When can a "quantum computer" reproduce all the calculations that can be done with a "classical computer".
Sounds like you are answering the first problem, but this is a very restricted problem. TFS (and quantum computer in popular press) implies the second problem.
E.g. From TFS "Superposition lets one qubit perform two calculations at once" makes me think a "calculation" is a floating point operation (FLOP), as in a classical computer. Comments suggest this is an incorrect interpretation?
(Score: 3, Interesting) by bradley13 on Friday May 22 2020, @05:11AM
Quantum computing is indeed a different beast. Still, the problems we want to solve remain the same, so it becomes a difference in framing. At least for the foreseeable future, any "real" use of a quantum computer will be as an addition to a classic computer. We offload floating-point operations to the floating-point unit on the processor, and we will offload other operations to the quantum-unit.
The whole argument about quantum supremacy seems ridiculous and artificial. They are trying to perform some calculation, and claiming that a classical computer cannot simulate the quantum solution. Whooopie. Real quantum supremacy will come, when you can hand off a real problem, and the quantum computer can get the same result as a classical computer, but in less time. Example: Find the factors of this ginormous number. When a quantum computer can deliver an answer (and the same answer) faster than a classical computer, then we have quantum supremacy.
Everyone is somebody else's weirdo.
(Score: 3, Funny) by Kitsune008 on Friday May 22 2020, @01:12AM (1 child)
You only need one Bourne of qubits for supremacy. ;-)
(Score: 0) by Anonymous Coward on Friday May 22 2020, @02:15AM
Repeat that three times and win a lecture from aristarchus.
(Score: 2) by takyon on Friday May 22 2020, @02:39AM (1 child)
https://spectrum.ieee.org/tech-talk/computing/hardware/quantum-inspire-launches [ieee.org]
If existing transistor fabrication technologies can be used to build a type of room-temperature qubit, then you could see millions, billions, or even trillions of qubits on a single chip relatively quickly. And that might be the scale needed to do anything useful, rather than 53 to 420 blazing qubits.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 1) by khallow on Friday May 22 2020, @05:05AM
I certainly don't buy that they can pull that off with 300 qubits even near absolute zero.
(Score: -1, Flamebait) by Ethanol-fueled on Friday May 22 2020, @02:41AM (6 children)
Do you hear me, snakes? I am the end. I am here to send you to your ultimate fate.
You'll make a fine quarry for my final hunt...in the imaginary game of Minecraft. You nasty motherfuckers are going to get your filthy asses down to Mejico and the rest of you will hurt justifying your allegiance to China. Nasty hooknose scum.
(Score: 3, Informative) by takyon on Friday May 22 2020, @03:01AM (4 children)
You are really running with the Minecraft meme [urbandictionary.com], eh?
SN is a great place to recycle retired (dead) memes.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: -1, Flamebait) by Ethanol-fueled on Friday May 22 2020, @03:07AM (3 children)
We're sick of the fucking Jews dictating their wants upon the rest of the population. So now it's time for you fucking Jews to live on our terms. You can ban me but you can't ban every other one of us pointing out every one of you ChiCom sympathizers trying to fuck our society.
(Score: 2) by takyon on Friday May 22 2020, @03:12AM (2 children)
We are in a Cold War with China, but most people don't realize it. So U.S. has probably lost Cold War II already. Accept your new overlords.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: -1, Flamebait) by Ethanol-fueled on Friday May 22 2020, @03:24AM (1 child)
You think we'll bow down to you? You can get me banned from Soylentnews but we can pin the Jews as your allies, then get rid of the both of you, in the game of minecraft. Fuck off, you Chinkscum. We'll get rid of you along with the Mexicans.
FAAAAKKKK YOUUUUUU!
(Score: 0) by Anonymous Coward on Friday May 22 2020, @04:41PM
Man your trolling is low effort these days. You either need more drugs or less.
(Score: 0) by Anonymous Coward on Friday May 22 2020, @06:22PM
Well, we know where the people too retarded for slashdot went.
(Score: 1, Funny) by Anonymous Coward on Friday May 22 2020, @03:54AM
By definition, no one can know how many qubits are needed, until one observes quantum supremacy.
(Score: 0, Offtopic) by Anonymous Coward on Friday May 22 2020, @05:07AM (1 child)
how many cubits can fit in the crack of a model's ass?
https://www.instagram.com/p/BbksKxBAsM-/ [instagram.com]
(Score: 0) by Anonymous Coward on Friday May 22 2020, @04:49PM
In my case, 0.2222
(Score: 1, Offtopic) by Gaaark on Friday May 22 2020, @11:08AM
"What's a qubit?"
---Some guy in jail getting drugged and raped by his cell-daddy.
--- Please remind me if I haven't been civil to you: I'm channeling MDC. ---Gaaark 2.0 ---
(Score: 0) by Anonymous Coward on Friday May 22 2020, @09:32PM
wouldn't you require a MORE powerful computer to verify those quantum results?
using quantum computer you get result in 2 seconds but to verify them using a tried and tested classical computer takes forever?
so i guess just do the quantum calculation 100 times and see if the same result ...err... mistake happens again?
anyways, some post-quantum minds will already have a plan set out and it goes "you cannot beat this calculation thus follow them".
everything will be planed by this global quantum brain for humankind and to get to oversee, maintain and ask it questions you will need a degree in everything, including a degree in secrecy, ass kissing and party line toeing ... that's after you have been implanted with a micro-bomb in your spinal cored ^_^