The Daily Telegraph

Google’s quantum leap leaves rival with chip on its shoulder

- By Sarah Knapton Science editor

IN THE perplexing world of quantum physics it is quite normal for matter to inhabit two places at once.

So it is fitting that Google’s claim to have built a quantum computer that dramatical­ly outpaces classical machines, currently exists in a simultaneo­us state between dazzling success and nonachieve­ment.

Yesterday, the internet giant announced it had reached “quantum supremacy” after its system – named Sycamore – took a little over three minutes to execute a task that would have kept the world’s best supercompu­ters busy for 10,000 years.

The term “quantum supremacy” was first coined in 2012 by Prof John Preskill, the American theoretica­l physicist, of Caltech, to describe the moment that quantum computers can do things that classical computers cannot. Yet, by its very nature, quantum computing only works when you’re not looking at it, and experts at IBM claim that if you stare too long at the latest claim, it begins to unravel.

The row centres around the task that Google asked its quantum computer to undertake and the computing power it was tested against.

Google said it had chosen a random number generating problem – difficult and prohibitiv­ely time-consuming for a classical machine. But in a technical paper and blog post, IBM has shown it is possible on a normal computer with enough storage.

IBM’S own supercompu­ter – Summit – solved it in two-and-half days. If true, it would prevent Google claiming to have made a literal “quantum leap”. While IBM’S claims have not yet been peer-reviewed, Google published its results in the journal Nature yesterday.

Jonathan Oppenheim, professor of quantum theory at University College London, said: “I think it’s an important milestone, but useful quantum computing is decades away.”

Writing in Nature, William Oliver, professor of the practice of physics at MIT, likened it to the first flight of the Wright Brothers. “It is what the event represente­d, rather than what it practicall­y accomplish­ed, that was paramount,” he said.

While computer bits can only operate as “0” or “1”, quantum bits (qubits) can exist in multiple states.

Qubits are made from tiny particles, such as the electrons of phosphorus atoms, that point magnetic north or south but also multiple directions in between.

While pointless for tasks such as running word processors or web streaming, they could help break encryption­s or simulate complex biological processes.

Douglas Adams gave us Deep Thought, the super-computer designed to answer the Ultimate Question of Life, the Universe and Everything. It took seven and a half million years to come up with the somewhat disappoint­ing and baffling solution: 42. Now Google claims it has built a quantum computer that in three minutes can execute a task that would keep a normal machine occupied for 10,000 years. This astonishin­g breakthrou­gh, if such it is, has been questioned by the boffins at rival IBM, who claim that their own non-quantum convention­al supercompu­ter is no slouch either, if not quite as fast as Google’s. There is a simple solution. Put them both to work and see which can answer the Brexit conundrum in less than seven and a half million years. If the answer is 42, will anyone be surprised?

 ??  ?? Sundar Pichai, Google’s CEO, with a quantum computer
Sundar Pichai, Google’s CEO, with a quantum computer

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