The ability of light to modify electronic properties of superconductors now proven (Press review)

Science Advances has published a study by an International team which comprises a number of Italian researchers.

High-temperature superconductivityis very much an open challenge to researchers in the field of condensed matter physics all over the world. Thirty years after the discovery of superconductivity in copper oxides, the several aspects that still need to be clarified are addressed through different and complementary approaches and techniques. Now, an innovative contribution has been given by an international team that has put together eleven science institutions in six countries.

In a study published by Science Advances, the research team developed a new experiment based on the use of ultrashort laser pulses in the ultraviolet energy spectrum (EUV) produced by the  ARTEMIS beamline at the Rutherford-Appleton laboratories (UK). This allowed for the first-ever observation in a high-temperature copper superconductor prototype of the dynamics of electrons across the entire Fermi surface (this is the definition of the surface in phase space used to describe the thermal, electrical, magnetic and optical properties of metals, semimetals and doped semiconductors). This advancement, impossible to obtain with conventional laser sources, has made it possible to study the dynamics of the so-called “antinodal” electronic states, which were inaccessible up to now.
“High-critical temperature superconductivity in this class of materials derives from the information coded by electrons which move along the copper-oxygen bonds, the so-called antinodal quasiparticles” – explained Claudio Giannetti of the Università Cattolica del Sacro Cuore in Milan, Italy, one of the scientists leading the experiment. “The novelty of this experiment – added Massimo Capone of SISSA, Trieste, who supervised the theoretical modelling of the experimental results – is that we managed to observe directly how the sudden excitation of light turns antinodal states, which are similar to insulators, into metal quasiparticles.”
“The results achieved are relevant not only for high-temperature superconductivity physics, but also for the development of new patterns for the optical manipulation of electronic properties in quantum materials” – stressed Federico Cilento, of Elettra-Sincrotrone, and Fulvio Parmigiani, of the University of Trieste. “Indeed, our results demonstrate that light can be used to create new properties that, although transient, are different from those of the same materials in balanced conditions. Such results open interesting prospects also for the development of ultrafast switches, the physical (electronic and optical) properties of which can be modulated to very high THz frequencies.”
Link to the article "Dynamics of correlation-frozen antinodal quasiparticles in superconducting cuprates"



Last Updated on Tuesday, 15 May 2018 15:50