In a new scientific publication, Google claims to have reached “quantum supremacy” with a 53-qubit quantum computer, meaning that it has solved a problem that no classical computer can solve within a reasonable timeframe. It is the first time this has been achieved, marking a major milestone in the field of quantum computing.
While the term supremacy is a bit of an exaggeration, as it concerns just one application, it shows that quantum computers with their qubits, albeit still years from commercialization in all likelihood, have finally reached a point where they have solved a problem that no transistor-based computer or supercomputer could ever solve, essentially proving that quantum computers indeed work. “To our knowledge, this experiment marks the first computation that can only be performed on a quantum processor,” the Google researchers wrote.
The experiment involved calculating the output of certain specialized circuits, with as input randomly generated numbers “produced through a specialized scenario involving quantum phenomena.” The quantum processor took 200 seconds to sample one instance of the quantum circuit one million times, while a supercomputer would require 20,000 years to perform that task, according to the researchers. The quantum computer used was Google’s 53-qubit Sycamore system, scaling back from their 72-qubit Bristlecone machine, although no reason was provided.
The researchers further predict that quantum computing power will grow at a double exponential rate, possibly referring to the exponential growth in capabilities with each new qubit, but with the number of qubits growing at an exponential rate akin to Moore’s Law.
Fortune claimed on Friday that the Financial Times first reported on the news. Google posted the paper to NASA.gov earlier this week, but it has since been taken down. A Google spokesperson declined to comment, but a source from Fortune says that the paper was probably accidentally published before it had passed the peer-review process.
Not too long ago, quantum computers belonged largely to science fiction. But in recent years, several companies have made progress in scaling up the number of qubits, including Google, IBM, Microsoft, and Intel. Last year, IBM already proved that quantum computers could be superior to classical ones for a certain problem, while Intel unveiled its 49-qubit Tangle Lake quantum computer at CES 2018.