THE material that revolutionised electronics has been endowed with even greater power: silicon has joined the ranks of the superconductors.

In theory, doping silicon with high enough levels of boron atoms should turn it into a superconductor, but getting enough boron into the silicon has been a problem. Now Etienne Bustarret at the French national research agency CNRS in Grenoble and his colleagues have cracked it.

They fired a laser pulse at a silicon wafer while passing boron chloride gas over it. The laser melted the silicon, allowing many more boron atoms than normal to enter. When the silicon solidified, the boron atoms were trapped. The team found that the doped silicon superconducted below -272.8 °C (Nature, vol 444, p 465). "We must be able to produce this effect at higher temperatures for it to become widely useful," Bustarret points out.