By observing events at the scale of single atoms, Cornell researchers have found evidence that the mechanism in high-temperature superconductors may be much more like that in low-temperature superconductors than was previously thought.

 

"This came as a huge shock," said J.C. Séamus Davis, Cornell professor of physics, who with colleagues reports the findings in the Aug. 3 issue of the journal Nature. 

Superconductors are materials that conduct electricity with virtually no resistance. The new research may shed light on how superconductivity works in modified copper oxides known as cuprates, which superconduct at the relatively "high" temperature of liquid nitrogen.
"The main expectation has been that electron pairing in cuprates is due to magnetic interactions. The objective of our experiment was to find the magnetic glue," Davis said.

Instead, the researchers found that the distribution of paired electrons in a common high-temperature superconductor was "disorderly," but that the distribution of phonons -- vibrating atoms in the crystal lattice -- was disorderly in just the same way.

The theory of low-temperature superconductivity says that electrons interacting with phonons join into pairs that are able to travel through the conductor without being scattered by atoms. These results suggest that a similar mechanism may be at least partly responsible for high-temperature superconductivity.

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