4
$\begingroup$

IBM CEO Arvind made a talk in HBO's Axios program. It seems that there are misconceptions/misleading/flaws in reasoning etc.

What are those!

Some of the details of the speech is given as;

IBM says its new Eagle processor can handle 127 qubits, a measure of quantum computing power. In topping 100 qubits, IBM says it has reached a milestone that allows quantum to surpass the power of a traditional computer.

  • "It is impossible to simulate it on something else, which implies it's more powerful than anything else," Krishna told "Axios on HBO." How it works: While traditional computing uses ones and zeroes and can try many possibilities in quick succession, quantum computing hones in on the right answer, making it well suited to tacking complex problems.

...

  • "Can it solve every problem? No," Krishna said. But, at the same time, he said you can't do the work that this computer can do on a traditional machine. "It would take a normal computer bigger than this planet to be able to do that."

  • Krishna has been bullish that quantum computing can establish an important place in the computing world within a few years, while others believe it could take a decade to establish a significant role.

Yes, but: The arrival of quantum computing also poses a unique problem. Much of modern cryptography is based on hiding data in a way that it would take modern computers too long to crack. But, with their different approach, quantum computers will be able to break many of today's encryption systems.

$\endgroup$
8
  • $\begingroup$ Assume this Q as part of our no false information motto, and the speech of Arvind contains more than the given text. It is interesting that it contains some serious flaws. $\endgroup$
    – kelalaka
    Nov 16 '21 at 16:49
  • $\begingroup$ 1) It is impossible to simulate it on something else! $\endgroup$
    – kelalaka
    Nov 16 '21 at 17:20
  • 3
    $\begingroup$ "It is impossible to simulate it on something else, which implies it's more powerful than anything else," - it is impossible for this Quantum Computer to simulate the microcontroller in my microwave - does that mean that the microcontroller is more powerful than the Quantum Computer? If not, why not? [Sorry, I just get real irritated when someone rants about "Quantum Supremacy", which I think is massively overhyped] $\endgroup$
    – poncho
    Nov 16 '21 at 17:32
  • $\begingroup$ @poncho that is my aim so that one can write a complete answer as a response for those. Aginst : SHARCS (2009) $\endgroup$
    – kelalaka
    Nov 16 '21 at 17:39
  • 1
    $\begingroup$ Theres more... qubits alone are not sufficient. one would need to keep them coherent for a certain time (e.g. enough time to perform a few thousand quantum gates on them. Not to mention that this would need to be 128 logical qubits (i.e. after all the error correction), and that quantum gates can be applied to a entangled state on all of the qubits... $\endgroup$
    – Fleeep
    Nov 16 '21 at 18:37
6
$\begingroup$

IBM says its new Eagle processor can handle 127 qubits, a measure of quantum computing power.

I have no doubt that they have 127 physical qubits. I'm not sure how stable it is or anything else though.


In topping 100 qubits, IBM says it has reached a milestone that allows quantum to surpass the power of a traditional computer.

That's too broad a claim, even though Arvind Krishna tries and explain what he means later on. Because I have no doubt that it cannot perform 99% of the tasks that a normal computer can, and it would be slower and probably less precise for 99% of the 1% of the tasks that remain (assuming that you can meaningfully quantify "tasks" or "problems").


"It is impossible to simulate it on something else, which implies it's more powerful than anything else," Krishna told "Axios on HBO."

This sentence about quantum supremacy is what strikes most as dishonest and for good reason. First of all there is the flawed reasoning that anything that cannot be simulated on another computer is automatically more powerful.

Furthermore, quantum supremacy has been claimed before. In those very specific problem fields quantum cryptography has been claimed from a theoretical standpoint, while others have questioned those claims.

Instead of trying to refute it, let's show a small section of an interview with Google on Nature where they claim quantum supremacy. Nature of course has a different audience which means that they can dive a bit deeper:

In reality, Monroe adds, scientists are yet to show that a programmable quantum computer can solve a useful task that cannot be done any other way, such as by calculating the electronic structure of a particular molecule — a fiendish problem that requires modelling multiple quantum interactions. Another important step, says Aaronson, is demonstrating quantum supremacy in an algorithm that uses a process known as error correction — a method to correct for noise-induced errors that would otherwise ruin a calculation. Physicists think this will be essential to getting quantum computers to function at scale.

This kind of nuance is missing entirely from the interview.


How it works: While traditional computing uses ones and zeroes and can try many possibilities in quick succession, quantum computing hones in on the right answer, making it well suited to tacking complex problems.

"hone in" implies intent. This is a description of how quantum computer works for a layman, but it sneakily makes it look "smart" and relatable by personifying the device.


"Can it solve every problem? No," Krishna said. But, at the same time, he said you can't do the work that this computer can do on a traditional machine. "It would take a normal computer bigger than this planet to be able to do that."

This seems to be true of a full quantum computer, rather than their current machines. Unfortunately the calculation seems to be missing.


Krishna has been bullish that quantum computing can establish an important place in the computing world within a few years, while others believe it could take a decade to establish a significant role.

I'd share myself amongst the skeptical persons on this, although it might be that we find a few specific problems before that. But predicting the future is not hard science.


Yes, but: The arrival of quantum computing also poses a unique problem. Much of modern cryptography is based on hiding data in a way that it would take modern computers too long to crack. But, with their different approach, quantum computers will be able to break many of today's encryption systems.

That is almost certainly a decade out, but we should be preparing, and possibly at a faster pace for things like long term secrets and signatures that need to be verified far into the future (although those could be re-signed for some use cases, I suppose). Fortunately the replacements for those algorithms that are vulnerable are already out there. Still, updating the existing PKI infrastructures is going to be a huge undertaking.


Conclusion: in my opinion the speech of Mr Krishna to bring the news in such a way that it can be understood by a layman (i.e. investors). However, it seems everything in the interview is geared towards emphasizing the claim. The interview doesn't go into any of the drawbacks of the current quantum computers, which are not solving real world problems yet, and probably won't be for a while.

I have no doubt that quantum supremacy exists, and possibly we can get to a stage where it is shown and that scientific consensus agrees on it. Because then the scientists can focus on creating a quantum computer that can actually solve real world problems. Before that we're probably stuck with every company that works in the field making the same claim once they topple the previous record number of qubits.

Fortunately I think we've now already had Google and IBM claiming quantum supremacy (as well as a lab in China), so unless they are dishonest enough to claim it multiple times, they are out of the race. To my surprise I found that D-Wave only claimed a "quantum computational advantage", steering clear of the "quantum supremacy" term because they could envision that there was a smart algorithm possible on a normal computer that would solve their particular problem.

Although not as "sexy" a term, (like Monroe in the Nature article) I would really welcome the first announcement that shows practical quantum error correction, because I don't see a bright future for quantum computers without it.

$\endgroup$
2
  • 1
    $\begingroup$ Finally, someone wrote an answer. For a long time, we know that AES-256 is secure against quantum even AES-128 since it is not clear how one can execute $2^{64}$ successive calls. So block ciphers and Hashes are secure, the problem was with public key systems. $\endgroup$
    – kelalaka
    Nov 17 '21 at 15:04
  • 1
    $\begingroup$ Exactly what I wanted to say (only expressed better...) $\endgroup$
    – poncho
    Nov 17 '21 at 15:26

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.