As someone who understands little about quantum computing, why is quantum volume not a good measure?
I'd be thankful to better understand better what parts of the complicated system is lost in the measure.
I'd be thankful to better understand better what parts of the complicated system is lost in the measure.
https://qiskit.org/textbook/ch-quantum-hardware/measuring-qu...
Random circuits are really only good for proving that you are in fact operating a quantum computer, since you can test the results, and random quantum circuits can not be efficiently simulated by classical computers. So quantum volume is not a totally meaningless metric, but it doesn’t necessarily indicate any capability for real problems that people would like to use quantum computers on: factoring, solving discrete logs, general search problems, or simulating quantum physics systems.
https://www.forbes.com/sites/moorinsights/2019/11/23/quantum...
> Quantum Volume would also benefit the CEO or investor who lacks the in-depth technical knowledge necessary to make confident investment decisions in the technology. Additionally, reported variations in Quantum Volume from company to company would likely stimulate more articles by the media, which would serve to educate the general public further.
Look at your computer. It's got a processor with a certain number of cores, a maximum clock frequency, a hierarchical cache system with varying sizes; it's got a certain amount of RAM with its own operating frequency; a graphics card with some number of cores, its own RAM and clock frequency. Imagine that I hand you a single number that's supposed to encapsulate all that information -- let's say something of the form frequency * cores * ram. And... maybe that kinda makes sense? But it doesn't actually correspond to any kind of real-world performance.
The issue isn't so much that there's parts lost in the measure -- rather, they've thrown in the kitchen sink and it's hard to say what it all really means. Except convincing management, "big numbers go zoom!"
But it may correlate with performance, and that might be sufficient -- in the same way that Moore's law did for so long too
Can't really argue with that sort of hedge. I'd even go so far as to say it does correlate with performance on a completely artificial benchmark. But that's a far cry from "it faithfully describes computational power" that would justify the headline in question.