High-temperature superconductor spills secret: A new phase of matter
A collaboration organized by Zhi-Xun Shen, a member of the Stanford Institute for Materials and Energy Science (SIMES) at SLAC and a professor of physics at Stanford University, used three complementary experimental approaches to investigate a single material, the high-temperature superconductor Pb-Bi2201 (lead bismuth strontium lanthanum copper-oxide). Their results are the strongest evidence yet that the pseudogap phase, a mysterious electronic state peculiar to high-temperature superconductors, is not a gradual transition to superconductivity in these materials, as many have long believed. It is in fact a distinct phase of matter.
"This is a paradigm shift in the way we understand high-temperature superconductivity," says Ruihua He, lead author with Makoto Hashimoto of the paper in the March 25 issue of the journal Science that describes the team's findings. "The involvement of an additional phase, once fully understood, might open up new possibilities for achieving superconductivity at even higher temperatures in these materials." When the research was done Hashimoto and He were members of SIMES, of Stanford's Department of Applied Physics, and of Berkeley Lab's Advanced Light Source (ALS), where He is now a postdoctoral fellow.
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