Scientists have discovered a new nanoscale relationship between superconductivity (the passage of electric current without wasting energy) and the phenomena known as charge density waves.
The discovery, which was published in the journal Science, is an exciting step forward in the decades-long search for room-temperature superconductors that might usher in a new era of electronics and computing. Because superconducting materials function at extremely low temperatures, often below -320 degrees Fahrenheit, they are impracticable to utilise without a cooling mechanism. The development of superconductors that work at higher temperatures has the potential to alter everything from laptop computers to regional power systems.
“Knowing what makes these materials superconductors gets us closer to being able to control them. We’re looking for any connection that relates to their superconductivity,” said Eduardo H. da Silva Neto, an assistant professor of physics in Yale’s Faculty of Arts and Sciences and co-author of the new study.
The study focused on a substance called yttrium barium copper oxide, which was conducted by the US Department of Energy’s SLAC National Accelerator Laboratory at Stanford University and included experts from Yale, the University of British Columbia (YBCO), and other institutions. They discovered that YBCO’s superconductivity was linked to charge density waves — disturbances in the density of electrons in the material — at the nanoscale.
The material’s charge density waves rose and ordered themselves in a more equal, coordinated manner when the scientists lowered its superconductivity by exposing it to infrared light. When superconductivity was strengthened, however, the charge density waves in the material became less structured.
“In other words, superconductivity and charge density waves co-exist but they don’t like each other,” da Silva Neto said. “We’ve essentially found a ‘tuning knob’ to alter the shape of charge density waves, through increased or decreased superconductivity.” Scientists’ next step, according to da Silva Neto, is to reverse the process and find ways to manipulate superconductivity using charge density waves.
Access to the SLAC National Accelerator Laboratory, an underground facility in Menlo Park, California, committed to a broad programme in atomic and solid-state physics, chemistry, biology, and medicine, was a critical component of the research, he added.