Quantum computing is now on launchpad

Chinese researchers revealed this month that they have built a quantum computer capable of performing in minutes calculations that would theoretically take today's most powerful supercomputers millions of years.

The machine, which relies on manipulating particles of light, has enabled the scientists to claim they have achieved so-called quantum supremacy, a year after Google said it had achieved "quantum advantage" with a supercomputer that uses ultra-cooled superconducting chips.

Both projects are part of international efforts to push computing to the next and previously unattainable level that, until now, had been largely theoretical.

Lu Chaoyang, a professor in charge of the experiment at the University of Science and Technology of China in Hefei, the capital of Anhui province, was quoted as saying, "Building a quantum computer is a race between humans and nature, not between countries."

As the biggest brains in computing and quantum physics assess the significance of the breakthrough, it would seem almost churlish for us ordinary mortals, who struggle to keep our laptop software updated, to ask what the machine actually does. Is the breakthrough beneficial? Does it offer any practical advantages for improving our lives?

Hefei's Jiuzhang experiment focused on performing one specific, complex mathematical task beyond the range of conventional computers.

Traditional computing relies on binary bits whose value is expressed as either zero or one. In quantum computing, bits can be both one and zero at the same time, exponentially increasing their processing power and making them trillions of times faster.

The machine used beams of laser light to perform a computation that would be practically impossible on a conventional computer.

Although, for now, the Chinese computer can only perform one task, the next stage is to create a quantum machine that would be fully programmable and capable of addressing a range of calculations.

The Hefei team believes the supercomputing capacity has potential in areas such as machine learning and quantum chemistry. It could also hasten medical advances, a potential that takes on particular significance in a pandemic year.

Some skeptics believe that may be a long haul and that the next steps, beyond the so-called boson sampling that the latest experiment achieves, may be very difficult to achieve.

That is unlikely to deter the international researchers, or indeed the private companies and governments that fund them. Venture capitalists have poured billions of investor dollars into what has been described as a quantum gold rush, hoping to cash in on the as yet unproven practical applications of the technology.

The science magazine Nature estimated that, by the start of 2019, private investors had funded more than 50 quantum technology companies globally since 2012.

Some are betting that it might be possible to market an early task-specific quantum computer that could, for example, simulate a chemical reaction or optimize a financial model.

The field has also attracted large-scale government funding.

All new technology has its potential downsides, and advances in quantum computing have inevitably given rise to concerns, particularly in the field of internet security.

Today's data is protected by encryption technology that would take a conventional computer hundreds of years to pick apart. Theoretically, a quantum computer could crack the codes in minutes, a threat that has given rise to the related field of quantum cryptography.

It is in its early days, but quantum computing has the potential to revolutionize a range of disciplines. Science invariably advances from the theoretical to the practical, defying the skeptics who challenge whether it is worthwhile pouring money into unproven and seemingly esoteric research.

Polling in the 1960s found that more than half of the people in the United States thought their government's investment in space technology was a waste of money, an opinion that changed once astronauts finally made it to the moon.

Since then, the so-called space race has transformed the world in a variety of ways, from a revolution in satellite-based communications technology to advances in scientific and medical research and robotics.

With the Chinese breakthrough and other global advances, quantum computers are now on their own launchpad, ready to take off, even if we are not quite sure yet what unforeseen and incalculable practical benefits might one day emerge.