[gobengo]

> Can these computers actually do something better than their classical counterparts, right now?

The answer is yes. Sometimes this is referred to as 'quantum supremacy' and some researchers at Google declared it in 2019.

https://www.nature.com/articles/s41586-019-1666-5 https://ai.googleblog.com/2019/10/quantum-supremacy-using-pr...

[isoprophlex]

Thanks, interesting idea but it seems the practical applicability is still far away.

> One of the most celebrated results in quantum computing is the development of a quantum algorithm for factorization that works in time polynomial in n. This algorithm, due to Peter Shor and known as Shor’s algorithm, runs in O (n3 log n) time and uses O (n2 log n log log n) gates. The first experimental implementation of this algorithm on a quantum computer was reported in 2001, when the number 15 was factored. The largest integer factored by Shor’s algorithm so far is 21.

[YakBizzarro]

Quantum supremacy, while a very interesting experiment and a milestone in quantum computing, proves hardly anything about usefulness of quantum computers. It "only" proves that quantum computers are the best quantum computers, and classic ones can't efficiently simulate them. It say nothing about useful operations.

[s1dev]

From a theoretical point of view, this is evidence that quantum computing is a more powerful model of computation. I think it would be hard to argue that a model of computation that can solve more problems is any less useful. Applications like quantum simulation do appear to be difficult on a classical computer yet efficiently computable on a quantum computer

[oldgradstudent]

In what sense the result describes a computation? And it what sense the device describes is a computer?

The only thing it can do faster is to run itself.

It's as if I called a Boeing airliner an aerodynamic computer and each flight a computaion.

[krastanov]

They are programmable, that makes them drastically more intetesting than a single-parameter aerodynamic analog computer like the Boeing, from the point of view of Computational Complexity. It does not make them "useful" yet, but it is a big milestone. See https://scottaaronson.blog/?p=5460