Actual Uses for Near-Term Quantum Computers

TFA article mentions 5 use cases that are supposedly "within the coming decade" and uses terms such as "few million qubits" "more qubits than are currently available" and "within reach", basically implying that there aren't any use cases possible now. This seems to reinforce skepticism[1] expressed by other researchers that practical uses of quantum computing will very likely be different from what we thought possible before, quote - "big compute" problems on small data, not big data problems.

As a newbie I seriously would like to know - are there ANY known real world applications of quantum computing that are possible today?

[1] https://cacm.acm.org/research/disentangling-hype-from-practi...

Shameless plug: But these types of areas of research (what types of problems can quantum computers solve and when) has been a big focus of our open-source Q# effort lately. You can see our last two blog posts (https://devblogs.microsoft.com/qsharp/) are about the resource estimation features we've recently built for exactly this purpose. You can give them a try pretty easily in VS Code or just in the browser (https://aka.ms/AQ/RE/Docs)

Disclaimer: I work on the Q# project (https://github.com/microsoft/qsharp) in a team under Matthias Troyer (quoted in the article).

Entirely personal option: I do think tempering some of the hype of the past few years/decades and focusing on the areas of highest potential is in general a good thing. Progress hasn't been what some optimists had hoped for, but hardware has been progressing quite quickly & consistently for years now, and I'm confident we'll get there eventually.

> and destroying Internet security seems like a dubious reason to build a new machine

In the same way technological advancements in radar and signals brought aerial superiority, the first-mover in PQC will bring both technical and cybersecurity superiority.

In 2015 people assumed we'd need 1 billion qubit computers to break 2048-bit RSA.

That estimate changed to 20 million in 2019.

We're 5 years on from that and quantum supercomputers are 16x more powerful than they were in 2019.

Based on our current rate of advancement, we'll likely be there within 10 years or less, even if the estimated amount of resources required don't decrease from improvements on the cracking side.

I think of them now as special-purpose accelerators, or, perhaps better, analog computers for simulating quantum phenomena.

But that's because of their current limitations - they still need a classical computer to set them up, the same way analog computers were configured to perform a specific job with wires, amplifiers, and function generators (because we didn't have digital computers that could do that for us). What would a function itself represented as a network of qubits to be applied on data qubits even look like?

> ... destroying Internet security seems like a dubious reason to build a new machine.

I can't agree with this; Destroying internet security is an excellent reason to build a new machine.

understanding quantum phenomena associated with developing a quantum computer is in itself cool enough to justify investment into it, at least at the academic level. People have been making these really cool electronic devices, making 'magic' atoms with protected quantum states. Quantum computing, even if a working device never gets constructed, is like a bottomless well of interesting quantum curiosities.