THE long-standing quest to find a new type of superconductor, first predicted in the 1960s, has finally come to an end.
The theory of superconductors says that electrons have to pair up before they can pass through a material without resistance. In all the superconductors studied up to now, electrons do this by picking partners with opposite spin to themselves. But the theory also allows electrons with the same spin to get together.
Now Ying Liu at Pennsylvania State University and colleagues have found the first superconductor in which this happens. They say that electrons in strontium ruthenate cooled to close to absolute zero pair up with partners of the same spin (Science, vol 306, p1151). Other experiments over the past 10 years have hinted that strontium ruthenate might be different but Liu and colleagues are the first to pin it down, says Derek Lee at Imperial College in London.
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