I guess someone will eventually introduce some kind of terminology like, "qubit equivalent". But I think that if you could build an error free 128 qubit machine, this would be interesting. But the main reason I see for that is if you can build one with 128 qubits, almost certainly someone with a lot more money than you, with a black budget, can build one much larger. The basic thrust of the article, and the paper, seems to be that if you can engineer a large enough quantum computer than doesn't really work, you can simulate one that doesn't exist. It's truly great if they are right, but I can't find a single statement about this paper on the entire web by an expert that is enthused about this announcement. The paper is short enough that there should be some comment by now.

Someone has already done that:

https://www.research.ibm.com/ibm-q/resources/quantum-volume....

That's a very specific number, do you know what the relevance of 128 is?

No I don't think it was specific. I believe he was just guesstimating the exponential power required to do anything more interesting than basic math. We were all rather young students at the time so I don't think he had a specific application in mind. It was all rather new back then anyways, hard to imagine all the applications.

He is probably referencing the 128 bit security threshold most crypto systems seek to achieve. However this doesn’t really line up with the number of qubits needed to break said crypto, which is typically much larger (thousands of qubits, plus error correction to survive millions of operations).

Edit: less than a doubling. Eg from 128 to 192 or from 256 to 384. I meant to say a doubling is sufficient.