Superconductors, Italy’s new frontier (Press review)

Researchers from Brescia and Trieste “filmed”, for the first time, the change in optical properties in high-temperature superconductors, paving the way for the transport of electricity without dissipation. Their research was published in Nature Communications. Trieste – Brescia. Transporting electricity through wires and circuits without dissipating energy; producing very elevated magnetic fields without having to cool the material, a very useful property in the field of magnetic levitation:

these are just two of the fields of application that might benefit from the discoveries of the basic research of a group of Italian researchers from the  Department of Physics of the Catholic University of Brescia, the Department of Physics of the University of Trieste and Sincrotrone Trieste S.C.p.A.

A technique developed by the Italian physicists has made it possible to “film” the change in optical properties – what we perceive as “colour” – on a timescale of about 0.000000000001 seconds (1 picosecond), after the system has been brought out of equilibrium by an pulse of light. The extremely fine temporal resolution has made it possible to show, for the first time, that the formation of superconductivity at high temperatures is associated with a change of “colour” in the material for an extremely brief span of time (about 10 picoseconds). This phenomenon, which is impossible to measure with traditional techniques, is completely absent from traditional superconductors (so-called low-temperature superconductors) and is an important step forward towards fully understanding this phenomenon.

This international study was coordinated by Dr. Claudio Giannetti and Dr. Gabriele Ferrini (Catholic University of Brescia) and Prof. Fulvio Parmigiani (University of Trieste and Sincrotrone Trieste S.C.p.A.) in collaboration with the University of British Columbia (Vancouver, Canada), the University of Geneva, the University of Minnesota, and the National Institute of Advanced Industrial Science and Technology in Tsukuba (Japan). It addresses one of the unsolved problems in the field of condensed matter physics: the origins of conductivity at critical temperatures (see “Open Questions in Physics”, “List of unsolved problems in physics”). Critical temperature superconductors include all the materials which become superconductors – meaning electrical resistance becomes zero – at a temperature of over 30 K (-243 °C). The first such superconductors were discovered in 1986 by Karl Müller and Johannes Bednorz, who won the Nobel Prize for Physics the following year. In spite of 25 years of research and over 100,000 papers published in scientific journals, the physical mechanism underpinning this phenomenon remains unclear.

A better understanding of high temperature superconductivity would have key implications both with regards to the theories that describe the properties of these systems, with are based on metal oxides, and to their applications: they could pave the way for engineering superconductive materials at room temperature, which could, for example, transport electricity without dissipation, with a major impact on both the transportation of electricity, which would take place without waste, and on the development of electronic equipment that does not heat up while in function. Thanks to the possibility of producing very high magnetic fields without cooling the material, another application could be in the field of transport using magnetic levitation, in which a vehicle is suspended thanks to a high-intensity magnetic field. The results obtain confirm how the labs of the Physics Departments on the Universities of Brescia and Trieste produce  internationally-significant research, and allow young researchers and students completing their degree courses to grapple with the most cutting-edge research themes in the field of condensed matter.