Laser Triggered Superconductivity

This may be very important.  We have here a way to test forsuperconductivity over a wide range of materials and their multiple variationsand various temperatures.

It also suggests that it will bepossible to establish single layer materials that may have conductivity turnedon through a mask to provide a superconductive circuit board.  If this is not neat, then what is?

There is obviously plenty of labwork to conduct to see where this all goes but the possibility is nowconfirmed.

Light touch transforms material into a superconductor

14 Jan 11

Professor Andrea Cavalleri used laser light to transform a materialinto a superconductor

A non-superconducting material has been transformed into asuperconductor using light, Oxford University researchersreport.

One hundred years after superconductivity was first observed in 1911,the team from Oxford, Germanyand Japanobserved conclusive signatures of superconductivity after hitting anon-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 OxfordUniversity and the Max Planck Department for Structural Dynamics, Hamburg.‘That’s already exciting in terms of what it tells us about this class ofmaterials. But the question now is can we take a material to a much highertemperature and make it a superconductor?’

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

In the journal Science, they describe how a strong infrared laserpulse 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, almostinstantaneously became a superconductor for a fraction of a second, beforerelaxing back to its normal state.

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

But the question now is can we take a material to a much highertemperature and make it a superconductor?

Professor Andrea Cavalleri

High-temperature superconductors can be found among a class ofmaterials made up of layers of copper oxide, and typically superconduct up to atemperature of around –170°C. They are complex materials where the rightinterplay of the atoms and electrons is thought to ‘line up’ the electrons in astate where they collectively move through the material with no resistance.

‘We have shown that the non-superconducting state and thesuperconducting one are not that different in these materials, in that it takesonly a millionth of a millionth of a second to make the electrons “synch up”and superconduct,’ says Professor Cavalleri. ‘This must mean that they wereessentially already synched in the non-superconductor, but something waspreventing them from sliding around with zero resistance. The precisely tunedlaser light removes the frustration, unlocking the superconductivity.’

The advance immediately offers a new way to probe with great controlhow superconductivity arises in this class of materials, a puzzle ever sincehigh-temperature superconductors were first discovered in 1986.

But the researchers are hopeful it could also offer a new route toobtaining superconductivity at higher temperatures. If superconductors thatwork at room temperature could be achieved, it would open up many moretechnological applications.

‘There is a school of thought that it should be possible to achievesuperconductivity at much higher temperatures, but that some competing type oforder in the material gets in the way,’ says Professor Cavalleri. ‘We should beable to explore this idea and see if we can disrupt the competing order toreveal superconductivity at higher temperatures. It’s certainly worth trying!’

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