8 June 2002

Quantum superbrains

IN THE quantum steeplechase, the runners are competing for a prize beyond riches: a computer so powerful it can simulate the most complex and mysterious aspects of the Universe without breaking sweat, leaving today’s supercomputers looking like ageing nags.

Many of the runners have already attracted widespread interest. But could this be a race in which the fences are so menacing, the distances so vast and the water jump so expansive that nobody makes it to the finish?

It wouldn’t be the first time. Forty years ago, researchers claimed they could harness nuclear fusion to generate cheap, clean power. Today, such power stations are as far off as ever.

Pushing technology beyond the limits of known science is always risky. No one can tell what unimaginable complexities will arise or what laws of physics will emerge to thwart you. Quantum physicists will have several tricky fences to jump before they can build their devices, and their dreams may rapidly change into nightmares.

What makes a quantum computer such a glittering prize? The key is in the nature of the information it would exploit. Think of ordinary information and you probably imagine the 0s and 1s of binary code, but that changes when you work with quantum particles. Information becomes a strange, ethereal substance, because quantum bits or qubits can be both a 0 and a 1 at the same time. And when put to work inside a quantum computer, they can do extraordinary things.

Take the spin of an electron. Think of it as being like the spin of a basketball with its axis pointing either up or down. Let’s …


To continue reading this premium article, subscribe for unlimited access.

Quarterly by Direct Debit

Inclusive of applicable taxes (VAT)
