Coupling occurs at temperature too high for superconductivity
Electrons zipping through a thin layer of strontium titanate interact and form pairs at higher temperatures than expected, researchers report in the May 14 Nature. The study is the first definitive evidence of coupled electrons in a solid material too warm for superconductivity, a state in which paired electrons move with no resistance. The research could help scientists better understand how superconductivity emerges and how to get materials to conduct electricity without resistance at or near room temperature.
Electrons tend to avoid each other, repelled by their negative charge. But within a select group of materials exposed to extremely low temperatures, electrons overcome their standoffishness and pair up. Two electrons mutually attracted to positively charged ions in the material lattice can couple to form a Cooper pair, which is crucial for superconductivity. Robert Schrieffer, who shared the 1972