Laser beams for superconductivity: Research sheds light on unexpected physical phenomena

October 25, 2017, International School of Advanced Studies (SISSA)
Credit: ORNL

A laser pulse, a special material, an extraordinary property which appears inexplicably. These are the main elements that emerge from a research conducted by an international team, coordinated by Michele Fabrizio and comprising Andrea Nava and Erio Tosatti from SISSA, Claudio Giannetti from the Università Cattolica di Brescia and Antoine Georges from the Collège de France. The results of their study have recently been published in the journal Nature Physics. The key element of the study is a compound of the most symmetrical molecule that exists in Nature, namely C60 bucky-ball, a spherical fullerene.

It is well known that this compound, with the chemical formula K3C60, can behave as a superconductor - that is, conduct without dissipating energy - below a critical temperature of 20 degrees Kelvin, i.e. around -253 degrees Celsius.

It has recently been discovered that K3C60 is capable of transforming into a high-temperature superconductor when struck by an extremely brief laser pulse. This material takes on superconductive properties - albeit extremely briefly - up to a temperature of -73 degrees Centigrade, almost 100 degrees above the critical equilibrium temperature. The research just published by the scientists explains the reason for this mysterious behaviour.

K3C60 is a compound in which purely molecular features coexist alongside metallic properties, a characteristic shared by so-called "strongly correlated" materials. According to the theory developed by the researchers in this study, the laser beam creates a high-energy molecular excitation, yet in order to do so it must absorb heat from the low-energy metallic component, which thus cools. As it is specifically the metallic component involved in conduction, its cooling may lead to a superconductivity phase despite the external temperature is higher than the .

As the researchers explain: "It is an example of laser cooling, yet with a new operating mechanism which had never been proposed until now. The fact that the pulse can transiently change the characteristics of a material is a significant observation. It may offer the prospect of manufacturing electronic devices whose properties change with the use of light, as if it were a switch. Indeed, the ultra-rapid control of materials with light sources is of great current interest for the scientific community and for the possible technological ramifications of these applications."

Explore further: Laser pulses reveal the superconductors of the future

More information: Andrea Nava et al, Cooling quasiparticles in A 3C 60 fullerides by excitonic mid-infrared absorption, Nature Physics (2017). DOI: 10.1038/nphys4288

Related Stories

Laser pulses reveal the superconductors of the future

May 10, 2017

An experiment at the cutting edge of condensed matter physics and materials science has revealed that the dream of more efficient energy usage can become reality. An international collaboration led by the scientists of Italy's ...

Superconductivity: Footballs with no resistance

February 9, 2016

Superconductors have long been confined to niche applications, due to the fact that the highest temperature at which even the best of these materials becomes resistance-free is minus 70 degrees Celsius. Nowadays they are ...

Recommended for you

Researchers study interactions in molecules using AI

October 19, 2018

Researchers from the University of Luxembourg, Technische Universität Berlin, and the Fritz Haber Institute of the Max Planck Society have combined machine learning and quantum mechanics to predict the dynamics and atomic ...

Pushing the extra cold frontiers of superconducting science

October 18, 2018

Measuring the properties of superconducting materials in magnetic fields at close to absolute zero temperatures is difficult, but necessary to understand their quantum properties. How cold? Lower than 0.05 Kelvin (-272°C).

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

KelDude
not rated yet Oct 26, 2017
Very nice to see the use of Celsius only temperatures in this article. Usually there is a Fahrenheit temperature indicated in brackets for the lowly US readers, the only country in the world still using the Fahrenheit temperature scale. Interestingly though, there is also the incorrect usage of the word Centigrade instead of Celsius. Still it's old school Fahrenheit numbers for the US readers that irk me the most in science articles.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.