Researchers just took a big step towards making superconductivity at room temperature happen. A cutting edge experiment has revealed that more efficient energy usage may soon be a reality. Researchers at Italy’s International School for Advanced Studies (SISSA), Università Cattolica di Brescia and Politecnico di Milano have used laser pulses to snap electronic interactions in a compound containing copper, oxygen, and bismuth. This discovery showed researchers the conditions when electrons don’t repel each other. This is essential for current to flow without resistance. The research gives scientists new perspectives for developing superconducting materials with applications in electronics, diagnostics, and transport.
Scientists used sophisticated laser techniques, which made it possible to investigate the non-equilibrium regime. They found a new way to understand properties of a special class of materials. The SISSA team worked on the theoretical aspects of the research, and the Universita Cattolica del Sacro Curoe and Politecnico di Milano worked on the experimental efforts.
"One of the greatest obstacles to exploiting superconductivity in everyday technology is that the most promising superconductors tend to turn into insulators at high temperatures and for low doping concentrations", the scientists explained. "This is because the electrons tend to repel each other instead of pairing up and moving in the direction of the current flow." To study this phenomenon, the researchers focused on a specific superconductor, which has highly complex physical and chemical properties, being composed of four different types of atoms, including copper and oxygen. "Using a laser pulse," the researchers elaborated, "we drove the material out of its equilibrium state. A second, ultra-short pulse then enabled us to disentangle the components that characterize the interaction between the electrons while the material was returning to equilibrium. Metaphorically, it was like taking a series of snapshots of the different properties of that material at different moments."
Through the new approach, the scientists found that "in this material, the repulsion between the electrons, and therefore their insulating properties, disappears even at room temperature. It is a very interesting observation as this is the essential prerequisite for turning a material into a superconductor. We will be able to take this material as a starting point and change its chemical composition, for example," the researchers explained. Now scientists have new tools to find the correct recipe for producing a superconductor at room temperature.
Having a superconductor at room temperature could benefit a few applications. The magnetic field generated by the passing current through a superconductor could be used for a new type of magnetic levitation train, similar to the ones already in use at Shanghai airport, but with far better performance and efficiency. It would make it possible to generate large magnetic fields in very small spaces, which, in turn, would make it possible to perform high accuracy magnetic resonance imaging on the small scale.
This study was published in the journal Nature Physics.