Google Announces It Has Reached Quantum Supremacy

On October 23rd, Google made a major announcement that it had reached quantum supremacy. For many people, that is an unknown term that could have stepped out of the pages of a Heinlein or Asimov novel. So, just what is ‘quantum supremacy’? And what difference will it make?

To put it simply, a team from Google in Mountain View, California, along with an experimental physicist named John Martinis from the University of California, had their quantum computer – called Sycamore – solve a specific and very difficult problem in 200 seconds.

Google vs IBM

Google claimed – as context – that the world’s currently fastest traditional computer – called Summit, owned by IBM and around the size of 2 basketball courts – would take 10,000 years to solve the same problem. One fly in Google’s ointment is that IBM have responded and said that Summit would actually only take 2.5 days to solve the problem, not 10,000 years.

While IBM’s response – still to be verified – takes a little of the sheen off Google’s announcement, it is still worth looking at the speed difference between the two: Sycamore took 200 seconds to solve the problem, and according to IBM, Summit would take approximately 216,000 seconds. So, even if the 10,000-year claim was inaccurate, the quantum computer is still operating over 100 times faster than what is recognised as the world’s fastest non-quantum computer.

But What is Quantum Supremacy?

The actual term ‘Quantum Supremacy’ refers to the point being reached where proof is present that quantum computers can outperform classical computers. This has long been known in theory, but this is the first time it has been proven in practice. And with the field of quantum computing a constantly developing one, that milestone may well go down in the annals of computing history.

Why is it a historic moment? If you look back, every single (non-quantum) computer on the planet, from antique 1960s models to your latest laptop or smartphone, all operate on the same rules and principles. These rules date back to Charles Babbage in the 19th century and to Alan Turing in the 1930s. A good analogy, to borrow from the world of fiction, is comparing the wheel to the hover board. Or to compare the wheel to the maglev technology currently in limited use, such as the airport link in Shanghai.

Is The Future Here?

But what does all this actually mean for us mere mortals with no grasp of the bewildering world of quantum physics, mechanics, and computing? Well, very little actually. Quantum computers being able to tackle and solve real life problems is likely still decades away, possibly more. But, as far as the ‘space race’ of quantum computing is concerned, this is the equivalent of getting the first man-made vehicle into orbit. What was only previous theory, though theory with a lot of belief in it, has now become fact. As Ciarán Gilligan-Lee of University College London states: “… it is the first baby step on a long road to getting useful quantum computers”.

There is a long – very long – way to go yet. While extremely fast, the scientists know that the quantum computers still make errors, so the next step for the Google team, and for the IBM team now playing catch-up, is to show that the teams can control qubits enough to get past these errors. Qubits? Qubits are quantum bits, the basic units of quantum information in quantum computing.

What is for sure is that there is a quantum computing space race going on. There are several teams around the world working, not only to make progress, but also to outdo each other and reach new milestones first.

Don’t Expect Miracles

While this announcement is groundbreaking, do not expect any more miraculous announcements in the near future. The next steps will be long and laboured examination and verification of the data, overcoming the inherent errors, reexamining and tweaking the algorithm, and generally checking every stage of their experiment for any mistakes. Other teams will be trying to replicate – or better – Google’s experiment, and teams using classical computers will be trying to find ways of closing the gap in computing time. The future is not quite here yet, but it is a lot closer.