Superconductivity is caused by pairing of electrons (formation of Cooper pairs). Usually the required electron-electron interaction is mediated by phonons –vibrations of positive ions in the crystal lattice. In this case Nature finds a smart way of avoiding direct Coulomb repulsion of equally charged electrons in the pair.

I supraledare paras elektroner ihop i så kallade Cooper-par. Hur detta sker i högtemperatur-supraledare har länge varit ett mysterium. Forskare vid Stockholms universitet presenterar i senaste numret av Nature Communications en ny typ av experiment som belyser frågan.