Five Ways to Think About Quantum Supremacy

Aventine reports:

When Google announced that it had achieved quantum supremacy in 2019, the headlines were thrilling.

The world of quantum computing had taken a remarkable step. Google, with its Sycamore quantum processor, had performed a calculation in 200 seconds that, the company claimed in the journal Nature, would take a supercomputer 10,000 years.

This feat, named quantum supremacy by John Preskill, a theoretical physicist, back in 2012, promised to usher in a new world of computing performance. ...

Only it didn’t play out the way Google hoped or expected. ...

And then, earlier this summer, researchers from Shanghai Artificial Intelligence Laboratory in China completed the same task in just 14.22 seconds, driving a final stake through the heart of the Google quantum supremacy claim.

It’s not the only warning sign for the industry. Venture capital investment in the sector has fallen off a cliff, from $2.2 billion globally in 2022 to about $1.2 billion in 2023.

It then reports the opinions of five experts, but none of them say that quantum supremacy has been achieved. The closest is Scott Aaronson who says:

Quantum supremacy can be achieved and then unachieved later. It’s a little bit of a moving target in that sense. But all expect that we’ll eventually get to a place where quantum computers are just routinely doing things that classical computers cannot replicate within thousands of years or millions of years, and at that point there’s no more arguing about it.

Achieved and then unachieved? This is a bit like a mathematician saying something was proved, and then disproved. If it was later disproved, then it was never really proved.

Gil Kalai argues that quantum supremacy is impossible, and explains further here.