Scientists create laser-activated superconductor

Shining lasers at superconductors can make them work at higher temperatures, suggests new findings from an international team of scientists including the University of Bath.

Superconductors are materials that conduct electricity without power loss and produce strong magnetic fields. They are used in medical scanners, super-fast electronic circuits and in Maglev trains which use superconducting magnets to make the train hover above the tracks, eliminating friction.

Currently superconductors only work at very low temperatures, requiring liquid nitrogen or helium to maintain their temperature. Now scientists publishing in the prestigious journal Nature have found a way to make certain materials superconduct at higher temperatures.

Laser-activated superconductor

The team, led by the Max Planck Institute for the Structure and Dynamics of Matter and including the Universities of Bath and Oxford, shone a laser at a material made up from potassium atoms and carbon atoms arranged in bucky ball structures and found it to still be superconducting at more than 100 degrees Kelvin - around minus 170 degrees Celsius.

The researchers hope these findings could lead to new routes and insights into making better superconductors that work at higher temperatures.

Superconducting at higher temperatures

Dr Stephen Clark , theoretical physicist at the University of Bath, worked with his experimental physicist colleagues to try to understand how superconductivity might emerge when the material is exposed to laser radiation.

He explained: "Superconductors currently only work at very low temperatures, requiring expensive cryogenics - if we can design materials that superconduct at higher temperatures, or even room temperature, it would eliminate the need for cooling, which would make them less expensive and more practical to use in a variety of applications.

"Our research has shown we can use lasers to make a material into a superconductor at much higher temperatures than it would do naturally. But having taken this first step, my colleagues and I will be trying to find other superconductors that can be coerced to work at even higher temperatures, possibly even at room temperature.

"Whilst this is a small piece of a very large puzzle, our findings provide a new pathway for engineering and controlling superconductivity that might help stimulate future breakthroughs."

91 per cent of physics research from the University of Bath was judged to be world-leading or internationally excellent by the in the recent independently-assessed  Research Excellence Framework 2014 .

International collaboration

The research was led by the Max Planck Institute for the Structure and Dynamics of Matter, (Hamburg, Germany). Other collaborating institutions were: The Hamburg Centre for Ultrafast Imaging (Hamburg, Germany), INSTM UdR Trieste-ST and Elettra - Sincrotrone Trieste (Trieste, Italy), Università di Roma "Sapienza" (Rome, Italy), Università degli Studi di Parma (Italy), University of Bath, (Bath UK), Oxford University (Oxford, UK), National University of Singapore.

European Research Council under the European Union’s Seventh Framework Programme funded the study.