Materials known as unconventional superconductors can conduct electricity with no loss at higher temperatures than regular superconductors. But after 40 years of research, those temperatures are still quite cold – about 140 degrees Celsius below the freezing point of water. Engineering them to operate in much warmer conditions – a development that could spur revolutions in energy, microelectronics and other fields – requires a much better understanding of how these complex materials work.
Almost all the research so far has focused on very fast processes that may contribute to superconductivity – for instance, natural, high-frequency vibrations known as phonons that rattle a material’s atomic latticework trillions of times per second.
Now researchers at the Department of Energy’s SLAC National Accelerator Laboratory have taken a new look from the opposite direction: They observed how an exceedingly slow process known as atomic relaxation changes in the presence of two of the quantum states that intertwine in cuprate superconductors.
The results suggest that the relaxation process is a promising tool for exploring and understanding those two states – charge density waves (CDWs), which are stripes of higher and lower electron density in the material, and the superconducting state itself, which switches on when the material chills below its transition temperature.
The research team described the results today in the Proceedings of the National Academy of Sciences.
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Image: A SLAC research team discovered how an exceedingly slow process known as atomic relaxation changes in the presence of two of the quantum states that intertwine in cuprate superconductors. The results suggest that the relaxation process is a promising tool for exploring and understanding those two states – charge density waves (depicted above), which are stripes of higher and lower electron density in the material, and the superconducting state itself, which switches on when the material chills below its transition temperature.
Credit: Greg Stewart/SLAC National Accelerator Laboratory