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IBM Finally Proves That Quantum Systems Are Faster Than Classical Systems (engadget.com)
In a paper published Thursday in the journal Science, Dr. Sergey Bravyi and his team reveal that they've developed a mathematical proof which, in specific cases, illustrates the quantum algorithm's inherent computational advantages over classical. Engadget reports: "It's good to know, because results like this become parts of algorithms," Bob Sutor, vice president of IBM Q Strategy and Ecosystem, told Engadget. "They become part of decisions about how people will start to attack problems. Where will they try classical techniques? Where will they try quantum techniques? How will those interplay? How will they work back and forth together?" What's more, the proof shows that, in these cases, the quantum algorithm can solve the problem in a fixed number of steps, regardless of how many inputs are added. With a classical computer, the more inputs you add, the more steps it needs to take in order to solve. Such are the advantages of parallel processing.
"The main point of this paper is not that somehow we discover some incredibly important quantum algorithm, or some practical, interesting problem," Bravyi told Engadget. "We ask if we can separate a constant depth [between] quantum and classical algorithms. As we increase the problem size, the runtime of the quantum algorithm remains constant, but the total number of operations grows." As Bravyi points out, this new proof doesn't, in and of itself, solve any existing computational issues. Instead, "it gives us insight into what makes a quantum computers more powerful," he continued. "And hopefully in the future it will lead to more practical, useful algorithms."
"The main point of this paper is not that somehow we discover some incredibly important quantum algorithm, or some practical, interesting problem," Bravyi told Engadget. "We ask if we can separate a constant depth [between] quantum and classical algorithms. As we increase the problem size, the runtime of the quantum algorithm remains constant, but the total number of operations grows." As Bravyi points out, this new proof doesn't, in and of itself, solve any existing computational issues. Instead, "it gives us insight into what makes a quantum computers more powerful," he continued. "And hopefully in the future it will lead to more practical, useful algorithms."
Congratulations to the IBM, this is an exciting result! Now lets just see if coherence times and the number of qubits can be scaled up as the researchers hope.
They proved that in their mathematical model, quantum systems are faster. No mathematical model that describes physical reality accurately is known at this time though and it is known that the current standard model cannot be true as it is inconsistent. Hence they did not actually prove anything about reality.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
The money will keep flowing. Now build something out here in reality that actually does something useful.
Do quantum computers exist?
The bad news is they used quantum logic for the proof.
So the results may be true or not.
I'll stop laughing when they break some crypto.
"we are all atheists about most of the gods that societies have ever believed in. Some of us just go one god further."
in theory. In practice however they differ.
Back 20+ year ago neural network was just like Quantum computing today. A few systems built around to try to prove what it could do, costing a lot of money and in general under-performing the traditional models. Now we have them on our smartphone and just used to make sure our face is ours and to place a dinosaur onto a live video feed.
If something is so important that you feel the need to post it on the internet... It probably isn't that important.
... they've developed a mathematical proof which, in specific cases ...
Identifying those cases reveals that there are problems that quantum computers (QC) cannot solve and that classical computers can.
While QC will bust current encryption wide open in a New York minute, QC will also create encryption that cannot be busted.
For those interested, look at "man in the middle," wiretapping that outs itself because it's making a measurement midstream and randomizing the fuck out of the process.
It little behooves the best of us to comment on the rest of us.
This is interesting because although something like Schor's algorithm for finding the order of an element in the multiplicative group of a field (and hence factoring) is faster than the best traditional algorithms, no one has actually proved that there isn't a faster method of factoring that would beat Schor.
"What lies behind us, and what lies before us are tiny matters compared to what lies within us." Ralph Waldo Emerson
Back 20+ year ago neural network was just like Quantum computing today.
Actually: no. Neural networks are a mature "science" sind minimum 30 years.
Now we have the processing power to run/train networks like Alpha Go. But the math did not change at all. Well, the new thing is that we have dedicated hardware for ANNs and don't need to run them on a CPU or GPU.
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
They have demonstrated mathematically that a hypothetical quantum computer could, at least in theory, do the kind of things that have people interested in quantum computing for.
Not to detract from the mathematical achievement, the news to me at least is that this hadn't been done yet.
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
This result is extremely narrow and does not offer any generality. In the specific problems space the researchers attacked they did not find that quantum computers were better than classical computers. What they state in the paper is something far more specific and thus less powerful. The comparison is between a 2D quantum grid of 1 qubit and 2 qubit gates versus a classical (probabilistic) circuit. They found that in the classical (probabilistic) circuit there is a strong lower bound on the depth of gates required to solve the problem (log n, where n is the size of the input). In the quantum grid case the depth remains constant as the computation is carried out over a 2D quantum grid.
Both Science and other write ups about this result, including this post, seems to paint this result very generally and it simply isn't. It's not an algorithm, the paper does not pit quantum vs classical computers, simply circuits. There is no analysis as to the size of the quantum grid required w.r.t. the size of the input, only the depth of the circuit. Also by leaning on probabilistic classical circuits they move the goalposts into an exotically small portion of the problem space.
The result is rather great, but it is nothing like the media is portraying and it is not a general result at all. Please don't take the above as anything other than media critique and clarification of the results in the paper.