Electrons find each other repulsive. Nothing personal – it’s just that their negative charges repel each other. So, getting them to pair up and travel together, like they do in superconducting materials, requires a little nudge.
In old-school superconductors, which were discovered in 1911 and conduct electric current with no resistance, but only at extremely cold temperatures, the nudge comes from vibrations in the material’s atomic lattice.
But in newer, “unconventional” superconductors – which are especially exciting because of their potential to operate at close to room temperature for things like zero-loss power transmission – no one knows for sure what the nudge is, although researchers think it might involve stripes of electric charge, waves of flip-flopping electron spins that create magnetic excitations, or some combination of things.
In the hope of learning more by looking at the problem from a slightly different angle, researchers at Stanford University and the Department of Energy’s SLAC National Accelerator Laboratory synthesized another unconventional superconductor family – the nickel oxides, or nickelates. Since then, they’ve spent three years investigating the nickelates’ properties and comparing them to one of the most famous unconventional superconductors, copper oxides or cuprates.