Light touch transforms material into a superconductor

One hundred years after superconductivity was first observed in 1911, a team from Oxford, Germany and Japan observed conclusive signatures of superconductivity after hitting a non-superconductor with a strong burst of laser light.

"We have used light to turn a normal insulator into a superconductor," says Professor Andrea Cavalleri of the Department of Physics at Oxford University and the Max Planck Department for Structural Dynamics, Hamburg. "That's already exciting in terms of what it tells us about this class of materials. But the question now is can we take a material to a much higher temperature and make it a superconductor?"

The material the researchers used is closely related to high-temperature copper oxide superconductors, but the arrangement of electrons and atoms normally act to frustrate any electronic current.

In the journal Science, they describe how a strong infrared laser pulse was used to perturb the positions of some of the atoms in the material. The compound, held at a temperature just 20 degrees above absolute zero, almost instantaneously became a superconductor for a fraction of a second, before relaxing back to its normal state.

Superconductivity describes the phenomenon where an electric current is able to travel through a material without any resistance – the material is a perfect electrical conductor without any energy loss.

"But the question now is can we take a material to a much higher temperature and make it a superconductor?" ponders  Professor Cavalleri