Comment Re:Nope (Score 4, Informative) 36
You are right that current QCs are still too small (and have too high an error rate) to implement any of the "quantum supremacy" algorithms that people dream about (like breaking cryptography). It will be a long time still before those are ready for realistic use. However, many scientists are actively studying quantum mechanics, and simulating such systems on conventional computers is extremely computationally expensive, owing to the complex non-classical correlations that underlie quantum effects (superposition, entanglement, etc.). There are rigorous theories/proofs showing how the effects go beyond the classical.
So the idea is to use a quantum computer to simulate a quantum system. You get all these "quantum correlations" for free. Of course you may consider this "cheating". It starts to sound less like quantum computing and more like doing a physical experiment that is highly analogous (rigorously analogous) to the experiment you are trying to understand. And you are limited to rather small systems. But, at least, this points to some interesting near-term goals for quantum computing folks to work on: how to make these systems better and better at simulating larger-and-larger quantum systems.