Ultrafast laser pulses can affect the properties of copper-based superconductors, a research team representing several Italian institutions has found. Cuprate superconductors function at relatively high temperatures around -200 °C. At slightly higher temperatures they retain some properties of superconductivity, a state called pseudogap. When the pseudogap material was illuminated with 100-fs pulses, the researchers said, it became more metallic. “What we induced is in fact a transient state — lasting less than a picosecond — which we realized was related to electron-electron interactions,” said Dr. Massimo Capone of the International School for Advanced Studies (SISSA) in Trieste. “The light pulses remove these interactions, making the electrons freer to flow, hence the metallic state.” The researchers said a deeper understanding of the pseudogap could have implications for medical imaging and transportation. “In addition to offering a theoretical framework for the phenomenon and providing new insight into this major family of superconductors, our study opens to an important possibility of controlling and modulating the characteristics of superconductors through the use of laser light,” Capone said. The research was published in Nature Communications (doi: 10.1038/ncomms5353). For more information, visit www.sissa.it.