Some of the main media (e.g. Financial Times or NASA’s website) recently ran a report that, prima facie, might seem ominous or menacing: “Google claims to have reached quantum supremacy”.
What does it mean to have achieved ‘quantum supremacy’? The term enshrines a fascinating race to be the first in achieving a Fully Operational Quantum Computer. In Europe and China this is mainly a race of public institutions. But in the United States the situation is quite different: there it is the biggest technology firms that are setting the pace: IBM, Google and Microsoft (and almost certainly Lockheed). These big firms currently have wads of spare cash for investment purposes and they are starting to spend it in areas sometimes far removed from their core business. Given the fierce competition that reigns between them, this means that it is there where the first quantum computer is likely to be achieved. And a lot quicker than we might think. Quantum Supremacy, in the jargon of quantum information theorists, means that, under certain conditions, a quantum computer outperforms a traditional, everyday computer in running any algorithm (a calculus). In the Google report the specific algorithm is run on its computer in three-and-a-half minutes, whereas a classical computer would take 10,000 years. This is why achieving Quantum Supremacy, even if it is not with a fully operational quantum computer, is considered to be an extraordinarily important step.
But what is Quantum Computing? Simply, it is a computer that works on the principles of the daunting quantum theory. Quantum theory, far from belonging to the realms of Sheldon Cooper and other freaks, is responsible for a quarter of the worldwide GDP. And it would allow a quantum computer to run algorithms that are impossible in the terrain of classical physics. Some of them are as important as the encryption algorithms that underpin web security and military communications.
To be considered quantum a computer has to tap into principles with names as thought-provoking and romantic as Superposition or Entanglement. The first is a fundamental principle of quantum mechanics whereby several states can coexist at the same time: 0/1; yes/no; up/down; etc. If this involves an information bit in the memory of a computer, the superposition principle makes it a quantum bit or qbit. Whenever a qbit that has been in superposed states is measured, it randomly chooses (with a probability determined by quantum theory) one only of these states. Quantum entanglement means we can kill two birds with one stone. What we do to a qbit automatically and instantly determines what happens to another qbit that is entangled with the first.
In a quantum computer, therefore, to compute anything, you simply prepare many qbits in a quantum state. And you measure. And the result is the solution to your algorithm. Courtesy of Mr. Schrödinger and his cat.
A cat that has survived Schrödinger’s experiment
So then the Google news hits NASA’s website. And a few minutes later the post is taken down. But it did give the Financial Times and other media time to take the story up. Why was it withdrawn? Conspiracy theorists (and Google’s competitors) immediately claimed it had been taken down because somebody didn’t want it to be known or that Google had jumped the gun and it wasn’t true. The funny thing is that the leakers of the news were NASA workers and we know they were collaborating with Google scientists and engineers on an article to be published in a science review of great prestige. And in such reviews everything to do with the subject of the article to be submitted undergoes an informative embargo policy. No one can say anything until it has been published in the review. In all likelihood, therefore, someone in NASA was unable to wait nearly a month before splashing his or her feat. And had to beat a hasty retreat. But what I sincerely believe is that Google has achieved what it claimed. With its 54 qbits. We’ll see in the coming weeks.
Author: Fernando Labarga
Las opiniones vertidas por el autor son enteramente suyas y no siempre representan la opinión de GMV
The author’s views are entirely his own and may not reflect the views of GMV