Applications of quantum computers after they become cheap enough and reliable enough as a binary computer

Question

Let's say in the near future Quantum Computers are as cheap as a high-end gaming PC or maybe Quantum Computing module that can work reliably when plugged into a PCI slot at a price similar to a high-end GPU is relased.

In this case what would be the uses of Quantum Computing in this case? Both Server and Client side uses can be considered?

Like for example would Quantum Computers be better than binary computers at graphics or file compression or encryption or secure communation over the internet or AI?

Or maybe applications that isn't common or doesn't exist now?

Answer 1

Made Community Wiki

Welcome to QCSE. These kinds of questions have come up here in the past, and maybe this site is not the best to give guidance (as the answers may be somewhat opinionated, etc.) The reddit forum has been pointed out as well.

But, breaking your question down, I don't know of too many people in the field who would accept the hypothesis that "in the near future Quantum Computers are as cheap as a high-end gaming PC" or a "quantum computing module that can work reliably when plugged into a PCI slot at a price similar to a high-end GPU is released". Most quantum computers are rather large, specialized machines that fill up a good portion of a room, and/or must be kept very close to absolute zero. To get out of that paradigm in "the near future" is likely beyond even the most optimistic conjectures.

Currently and likely in the near future (say the next 10 or so years) one communicates with a quantum computer over the cloud. The classical client engages with the quantum server.

The specific applications mentioned include (A) graphics, (B) file compression, (C) encryption, (D) secure communication over the internet, and (E) AI.

• For (A) and (B), a quantum computer is unlikely to provide any speedup, as GPU's already work very well and the classical algorithms are very efficient.
• For (C), quantum computing was made famous for decryption via Shor's algorithm, and not so much for encryption as proposed. However, there are some novel ideas about using a quantum computer for digital rights management and/or encrypted quantum money, but these will unlikely be realized in the near-term.
• For (D), secure communication over a quantum internet is indeed a use-case; the keywords there are quantum key exchange (QKD). There are some specific, and currently usable, approaches to QKD, although QKD solves a problem that's not yet broken, as we already have secure communication over the internet because we don't yet have quantum computers capable of running Shor's algorithm.
• For (E), artificial intelligence has been proposed as a use-case for quantum computers; I don't know much about it myself, but you can review quantum neural-networks (QNN)'s, for example. Many such algorithms fall into the quantum machine-learning (QML) class of problems, which has been going through a bit of an upheaval in view of a recent program initiated by E. Tang that shows many such quantum advantages are ephemeral.

A really more likely impact from current and near-term noisy, intermediate scale quantum computers will be in chemistry and/or materials science and/or physics experiments, rather than in graphics processing or compression or AI.

Answer 2

This is such an absurd and self-contradictory premise.

If we had such an advanced futuristic capability to create such a quantum device, we would not be using PCI slots and traditional PCs in the first place.

At that point, we would probably not care about file compression and graphics. I don't think any of the applications you presupposed would matter.

This reminded me of the movie Alien, filmed in 1979. It featured an advanced human cyborg who used an 8-bit computer while travelling in between stars. Somehow, cyborgs and interstellar travel developed faster than computers.