Quantum computers are getting closer, and competition in that new and exotic space is becoming increasingly fierce. That competition got a jolt in recent days thanks to a study published by Google on NASA's portal, which mysteriously disappeared. In that text, the Mountain View giant claims to have achieved quantum supremacy, a condition that, if true, will rewrite several rules in the future. But what does quantum supremacy mean, and why is Google's announcement being doubted?
The potential of quantum computers is gigantic. From the discovery of new chemicals and medicines to artificial intelligences and a true cryptographic revolution, the world eagerly awaits this mysterious generation of hardware and its applications. When it comes to two names associated with quantum computing, they are IBM and Google. The blue giant has been around here several times, starting with its first advances in 2012, the remote access to its quantum hardware in 2016, and the "music" of the IBM Q.
The other quantum titan is Google. Its experiments with the D-Wave platform did not go unnoticed, but now they have doubled down with an announcement that could change everything. I say "could" because the original article published on NASA's site vanished into thin air, and all that remains are isolated copies rescued by some press portals. In that article, Google announced quantum supremacy. Beyond the feeling of a crossover between James Bond and Jason Bourne, what does that phrase mean?
What is quantum supremacy?
Quantum supremacy emerges when a quantum computer demonstrates that it can solve a problem that is practically impossible for traditional supercomputers. Google achieved this through a problem of randomness: In relaxed terms, the goal of the exercise was to verify whether the result of a random number generator algorithm truly possesses a random distribution.
The Mountain View quantum platform Sycamore has a total of 54 qubits, but one of them apparently does not work, so it poured the other 53 into the search for the solution. Sycamore completed the task in 3 minutes and 20 seconds, which doesn't tell us much until we compare it with other systems. The fastest supercomputer on the planet is the IBM Summit, a monster of 148.6 petaflops. The same exercise that Sycamore solved in just over three minutes would have taken 10,000 years on Summit.
In March 2018, Google announced the creation of the Bristlecone processor with a total of 72 qubits, but according to available information, it was very difficult to control. That makes Sycamore seem like a compromise, but if 53 are enough to achieve quantum supremacy, nobody is going to complain… except Google's competitors. Dario Gil, chief research officer at IBM, came out against Google's supremacy by calling it "indefensible and simply wrong", since the research is nothing more than "a lab experiment" designed to implement a very specific quantum sampling procedure, without any practical application.
Now, it is no coincidence that this conflict manifests itself days after IBM announced its own 53-qubit quantum computer, which will soon become part of the IBM Q network. Leaving aside the word "supremacy", another very important aspect of Google's development is error correction and the reduction of "crosstalk" between qubits, something that professor Daniel Lidar of the University of Southern California sees as a real advance. At the same time, he considers that the story is not over for classical supercomputers, and with new programming techniques, they could match Sycamore. Quantum combat? Google versus IBM. We are ready.
Source: Financial Times (paywall)
Source: NewScientist
