Quantum computers have vast potential. They could eventually revolutionise everything from artificial intelligence to the development of new drugs. A working quantum computer could help create powerful new materials, turbocharge the fight against climate change and completely upend the cryptography that keeps our secrets safe. It would, as Discover magazine put it in the early days of research, be ‘less a machine than a force of nature’.
If their potential can be fully realised, these devices won’t simply be more powerful versions of our existing computers. They work in a completely different way, which could enable them to do seemingly impossible things. Because their strengths are so alien to the way most of us perceive the universe, it can be difficult to explain them without resorting to slightly fuzzy analogies. But effectively, quantum computers could unlock a new set of abilities based on the new, deeper understanding of the universe that physicists have developed over the last century.
In certain situations, quantum computers could allow us to do things that are impossible right now, even with the power of a million supercomputers. Believe the hype, and we’re on the verge of a new technological era, in which quantum computers will help us create more efficient travel routes, and crunch complex sums in scientific experiments. They’ll potentially change the way banks analyse risk, and allow chemists and biologists to create detailed simulations of the natural world to develop new, more efficient materials and processes. ‘This is one of the biggest technology jumps ever, in history,’ says William Hurley (known as Whurley), tech entrepreneur and founder of Strangeworks, which is working to make quantum computing accessible to all. ‘Computing will change more in the next ten years than it has in the last hundred.’
One of the most exciting applications of quantum computing could be in the field of machine learning. For decades, algorithms for classical computers were written by hand – painstakingly crafted by coders, who were like chefs writing down detailed recipes. But as computing power got cheaper, artificial intelligence and machine learning came to the fore. Now, the algorithms behind everything from facial recognition to online translation are more likely to be created by training a general-purpose program on a vast set of data. These technologies are hugely powerful. They can, for instance, diagnose lung cancer from scans more successfully than human experts. But they’re only as good as the data you feed them on. If you don’t have good enough data, or your underlying data is biased, you end up with flawed, biased algorithms.
Quantum computing offers the possibility of creating data where none actually exists in the real world, through a process known as generative modelling. It’s a process that’s already being carried out on classical computers, but quantum devices could do it faster and at a larger scale. ‘If we have a sample of a hundred things, we can use generative modelling to create things that are similar,’ explains Savoie. The additional power of quantum computers could be used to extrapolate from limited data sets, and feed machine-learning algorithms with data, even when we don’t have it. ‘Enhancing this allows us to do things with scant data – whether that’s looking for rare lung cancer in MRIs, or in facial recognition, where you have a lot of pictures of the side of a face but not the front of a face,’ says Savoie. It is, he says, like creating deep fakes that are as good as the real thing.
As deep fakes have demonstrated, tools like AI and machine learning can be hugely beneficial, or tremendously disruptive, depending on whose hands they’re in. Quantum computers are likely to have the same impact. If they work, they will undoubtedly bring benefits to the worlds of biology, chemistry and physics. But there are risks to such powerful machines being concentrated in the hands of a select few large companies or national governments. Some are worried that quantum computers could also upend the security systems that protect everything from banking systems to military secrets.